code
string | repo_name
string | path
string | language
string | license
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from collections import namedtuple
import sqlparse
from django.db import DatabaseError
from django.db.backends.base.introspection import BaseDatabaseIntrospection
from django.db.backends.base.introspection import FieldInfo as BaseFieldInfo
from django.db.backends.base.introspection import TableInfo
from django.db.models import Index
from django.utils.regex_helper import _lazy_re_compile
FieldInfo = namedtuple(
"FieldInfo", BaseFieldInfo._fields + ("pk", "has_json_constraint")
)
field_size_re = _lazy_re_compile(r"^\s*(?:var)?char\s*\(\s*(\d+)\s*\)\s*$")
def get_field_size(name):
"""Extract the size number from a "varchar(11)" type name"""
m = field_size_re.search(name)
return int(m[1]) if m else None
# This light wrapper "fakes" a dictionary interface, because some SQLite data
# types include variables in them -- e.g. "varchar(30)" -- and can't be matched
# as a simple dictionary lookup.
class FlexibleFieldLookupDict:
# Maps SQL types to Django Field types. Some of the SQL types have multiple
# entries here because SQLite allows for anything and doesn't normalize the
# field type; it uses whatever was given.
base_data_types_reverse = {
"bool": "BooleanField",
"boolean": "BooleanField",
"smallint": "SmallIntegerField",
"smallint unsigned": "PositiveSmallIntegerField",
"smallinteger": "SmallIntegerField",
"int": "IntegerField",
"integer": "IntegerField",
"bigint": "BigIntegerField",
"integer unsigned": "PositiveIntegerField",
"bigint unsigned": "PositiveBigIntegerField",
"decimal": "DecimalField",
"real": "FloatField",
"text": "TextField",
"char": "CharField",
"varchar": "CharField",
"blob": "BinaryField",
"date": "DateField",
"datetime": "DateTimeField",
"time": "TimeField",
}
def __getitem__(self, key):
key = key.lower().split("(", 1)[0].strip()
return self.base_data_types_reverse[key]
class DatabaseIntrospection(BaseDatabaseIntrospection):
data_types_reverse = FlexibleFieldLookupDict()
def get_field_type(self, data_type, description):
field_type = super().get_field_type(data_type, description)
if description.pk and field_type in {
"BigIntegerField",
"IntegerField",
"SmallIntegerField",
}:
# No support for BigAutoField or SmallAutoField as SQLite treats
# all integer primary keys as signed 64-bit integers.
return "AutoField"
if description.has_json_constraint:
return "JSONField"
return field_type
def get_table_list(self, cursor):
"""Return a list of table and view names in the current database."""
# Skip the sqlite_sequence system table used for autoincrement key
# generation.
cursor.execute(
"""
SELECT name, type FROM sqlite_master
WHERE type in ('table', 'view') AND NOT name='sqlite_sequence'
ORDER BY name"""
)
return [TableInfo(row[0], row[1][0]) for row in cursor.fetchall()]
def get_table_description(self, cursor, table_name):
"""
Return a description of the table with the DB-API cursor.description
interface.
"""
cursor.execute(
"PRAGMA table_info(%s)" % self.connection.ops.quote_name(table_name)
)
table_info = cursor.fetchall()
if not table_info:
raise DatabaseError(f"Table {table_name} does not exist (empty pragma).")
collations = self._get_column_collations(cursor, table_name)
json_columns = set()
if self.connection.features.can_introspect_json_field:
for line in table_info:
column = line[1]
json_constraint_sql = '%%json_valid("%s")%%' % column
has_json_constraint = cursor.execute(
"""
SELECT sql
FROM sqlite_master
WHERE
type = 'table' AND
name = %s AND
sql LIKE %s
""",
[table_name, json_constraint_sql],
).fetchone()
if has_json_constraint:
json_columns.add(column)
return [
FieldInfo(
name,
data_type,
get_field_size(data_type),
None,
None,
None,
not notnull,
default,
collations.get(name),
pk == 1,
name in json_columns,
)
for cid, name, data_type, notnull, default, pk in table_info
]
def get_sequences(self, cursor, table_name, table_fields=()):
pk_col = self.get_primary_key_column(cursor, table_name)
return [{"table": table_name, "column": pk_col}]
def get_relations(self, cursor, table_name):
"""
Return a dictionary of {column_name: (ref_column_name, ref_table_name)}
representing all foreign keys in the given table.
"""
cursor.execute(
"PRAGMA foreign_key_list(%s)" % self.connection.ops.quote_name(table_name)
)
return {
column_name: (ref_column_name, ref_table_name)
for (
_,
_,
ref_table_name,
column_name,
ref_column_name,
*_,
) in cursor.fetchall()
}
def get_primary_key_columns(self, cursor, table_name):
cursor.execute(
"PRAGMA table_info(%s)" % self.connection.ops.quote_name(table_name)
)
return [name for _, name, *_, pk in cursor.fetchall() if pk]
def _parse_column_or_constraint_definition(self, tokens, columns):
token = None
is_constraint_definition = None
field_name = None
constraint_name = None
unique = False
unique_columns = []
check = False
check_columns = []
braces_deep = 0
for token in tokens:
if token.match(sqlparse.tokens.Punctuation, "("):
braces_deep += 1
elif token.match(sqlparse.tokens.Punctuation, ")"):
braces_deep -= 1
if braces_deep < 0:
# End of columns and constraints for table definition.
break
elif braces_deep == 0 and token.match(sqlparse.tokens.Punctuation, ","):
# End of current column or constraint definition.
break
# Detect column or constraint definition by first token.
if is_constraint_definition is None:
is_constraint_definition = token.match(
sqlparse.tokens.Keyword, "CONSTRAINT"
)
if is_constraint_definition:
continue
if is_constraint_definition:
# Detect constraint name by second token.
if constraint_name is None:
if token.ttype in (sqlparse.tokens.Name, sqlparse.tokens.Keyword):
constraint_name = token.value
elif token.ttype == sqlparse.tokens.Literal.String.Symbol:
constraint_name = token.value[1:-1]
# Start constraint columns parsing after UNIQUE keyword.
if token.match(sqlparse.tokens.Keyword, "UNIQUE"):
unique = True
unique_braces_deep = braces_deep
elif unique:
if unique_braces_deep == braces_deep:
if unique_columns:
# Stop constraint parsing.
unique = False
continue
if token.ttype in (sqlparse.tokens.Name, sqlparse.tokens.Keyword):
unique_columns.append(token.value)
elif token.ttype == sqlparse.tokens.Literal.String.Symbol:
unique_columns.append(token.value[1:-1])
else:
# Detect field name by first token.
if field_name is None:
if token.ttype in (sqlparse.tokens.Name, sqlparse.tokens.Keyword):
field_name = token.value
elif token.ttype == sqlparse.tokens.Literal.String.Symbol:
field_name = token.value[1:-1]
if token.match(sqlparse.tokens.Keyword, "UNIQUE"):
unique_columns = [field_name]
# Start constraint columns parsing after CHECK keyword.
if token.match(sqlparse.tokens.Keyword, "CHECK"):
check = True
check_braces_deep = braces_deep
elif check:
if check_braces_deep == braces_deep:
if check_columns:
# Stop constraint parsing.
check = False
continue
if token.ttype in (sqlparse.tokens.Name, sqlparse.tokens.Keyword):
if token.value in columns:
check_columns.append(token.value)
elif token.ttype == sqlparse.tokens.Literal.String.Symbol:
if token.value[1:-1] in columns:
check_columns.append(token.value[1:-1])
unique_constraint = (
{
"unique": True,
"columns": unique_columns,
"primary_key": False,
"foreign_key": None,
"check": False,
"index": False,
}
if unique_columns
else None
)
check_constraint = (
{
"check": True,
"columns": check_columns,
"primary_key": False,
"unique": False,
"foreign_key": None,
"index": False,
}
if check_columns
else None
)
return constraint_name, unique_constraint, check_constraint, token
def _parse_table_constraints(self, sql, columns):
# Check constraint parsing is based of SQLite syntax diagram.
# https://www.sqlite.org/syntaxdiagrams.html#table-constraint
statement = sqlparse.parse(sql)[0]
constraints = {}
unnamed_constrains_index = 0
tokens = (token for token in statement.flatten() if not token.is_whitespace)
# Go to columns and constraint definition
for token in tokens:
if token.match(sqlparse.tokens.Punctuation, "("):
break
# Parse columns and constraint definition
while True:
(
constraint_name,
unique,
check,
end_token,
) = self._parse_column_or_constraint_definition(tokens, columns)
if unique:
if constraint_name:
constraints[constraint_name] = unique
else:
unnamed_constrains_index += 1
constraints[
"__unnamed_constraint_%s__" % unnamed_constrains_index
] = unique
if check:
if constraint_name:
constraints[constraint_name] = check
else:
unnamed_constrains_index += 1
constraints[
"__unnamed_constraint_%s__" % unnamed_constrains_index
] = check
if end_token.match(sqlparse.tokens.Punctuation, ")"):
break
return constraints
def get_constraints(self, cursor, table_name):
"""
Retrieve any constraints or keys (unique, pk, fk, check, index) across
one or more columns.
"""
constraints = {}
# Find inline check constraints.
try:
table_schema = cursor.execute(
"SELECT sql FROM sqlite_master WHERE type='table' and name=%s"
% (self.connection.ops.quote_name(table_name),)
).fetchone()[0]
except TypeError:
# table_name is a view.
pass
else:
columns = {
info.name for info in self.get_table_description(cursor, table_name)
}
constraints.update(self._parse_table_constraints(table_schema, columns))
# Get the index info
cursor.execute(
"PRAGMA index_list(%s)" % self.connection.ops.quote_name(table_name)
)
for row in cursor.fetchall():
# SQLite 3.8.9+ has 5 columns, however older versions only give 3
# columns. Discard last 2 columns if there.
number, index, unique = row[:3]
cursor.execute(
"SELECT sql FROM sqlite_master "
"WHERE type='index' AND name=%s" % self.connection.ops.quote_name(index)
)
# There's at most one row.
(sql,) = cursor.fetchone() or (None,)
# Inline constraints are already detected in
# _parse_table_constraints(). The reasons to avoid fetching inline
# constraints from `PRAGMA index_list` are:
# - Inline constraints can have a different name and information
# than what `PRAGMA index_list` gives.
# - Not all inline constraints may appear in `PRAGMA index_list`.
if not sql:
# An inline constraint
continue
# Get the index info for that index
cursor.execute(
"PRAGMA index_info(%s)" % self.connection.ops.quote_name(index)
)
for index_rank, column_rank, column in cursor.fetchall():
if index not in constraints:
constraints[index] = {
"columns": [],
"primary_key": False,
"unique": bool(unique),
"foreign_key": None,
"check": False,
"index": True,
}
constraints[index]["columns"].append(column)
# Add type and column orders for indexes
if constraints[index]["index"]:
# SQLite doesn't support any index type other than b-tree
constraints[index]["type"] = Index.suffix
orders = self._get_index_columns_orders(sql)
if orders is not None:
constraints[index]["orders"] = orders
# Get the PK
pk_columns = self.get_primary_key_columns(cursor, table_name)
if pk_columns:
# SQLite doesn't actually give a name to the PK constraint,
# so we invent one. This is fine, as the SQLite backend never
# deletes PK constraints by name, as you can't delete constraints
# in SQLite; we remake the table with a new PK instead.
constraints["__primary__"] = {
"columns": pk_columns,
"primary_key": True,
"unique": False, # It's not actually a unique constraint.
"foreign_key": None,
"check": False,
"index": False,
}
relations = enumerate(self.get_relations(cursor, table_name).items())
constraints.update(
{
f"fk_{index}": {
"columns": [column_name],
"primary_key": False,
"unique": False,
"foreign_key": (ref_table_name, ref_column_name),
"check": False,
"index": False,
}
for index, (column_name, (ref_column_name, ref_table_name)) in relations
}
)
return constraints
def _get_index_columns_orders(self, sql):
tokens = sqlparse.parse(sql)[0]
for token in tokens:
if isinstance(token, sqlparse.sql.Parenthesis):
columns = str(token).strip("()").split(", ")
return ["DESC" if info.endswith("DESC") else "ASC" for info in columns]
return None
def _get_column_collations(self, cursor, table_name):
row = cursor.execute(
"""
SELECT sql
FROM sqlite_master
WHERE type = 'table' AND name = %s
""",
[table_name],
).fetchone()
if not row:
return {}
sql = row[0]
columns = str(sqlparse.parse(sql)[0][-1]).strip("()").split(", ")
collations = {}
for column in columns:
tokens = column[1:].split()
column_name = tokens[0].strip('"')
for index, token in enumerate(tokens):
if token == "COLLATE":
collation = tokens[index + 1]
break
else:
collation = None
collations[column_name] = collation
return collations
|
castiel248/Convert
|
Lib/site-packages/django/db/backends/sqlite3/introspection.py
|
Python
|
mit
| 17,357 |
import datetime
import decimal
import uuid
from functools import lru_cache
from itertools import chain
from django.conf import settings
from django.core.exceptions import FieldError
from django.db import DatabaseError, NotSupportedError, models
from django.db.backends.base.operations import BaseDatabaseOperations
from django.db.models.constants import OnConflict
from django.db.models.expressions import Col
from django.utils import timezone
from django.utils.dateparse import parse_date, parse_datetime, parse_time
from django.utils.functional import cached_property
class DatabaseOperations(BaseDatabaseOperations):
cast_char_field_without_max_length = "text"
cast_data_types = {
"DateField": "TEXT",
"DateTimeField": "TEXT",
}
explain_prefix = "EXPLAIN QUERY PLAN"
# List of datatypes to that cannot be extracted with JSON_EXTRACT() on
# SQLite. Use JSON_TYPE() instead.
jsonfield_datatype_values = frozenset(["null", "false", "true"])
def bulk_batch_size(self, fields, objs):
"""
SQLite has a compile-time default (SQLITE_LIMIT_VARIABLE_NUMBER) of
999 variables per query.
If there's only a single field to insert, the limit is 500
(SQLITE_MAX_COMPOUND_SELECT).
"""
if len(fields) == 1:
return 500
elif len(fields) > 1:
return self.connection.features.max_query_params // len(fields)
else:
return len(objs)
def check_expression_support(self, expression):
bad_fields = (models.DateField, models.DateTimeField, models.TimeField)
bad_aggregates = (models.Sum, models.Avg, models.Variance, models.StdDev)
if isinstance(expression, bad_aggregates):
for expr in expression.get_source_expressions():
try:
output_field = expr.output_field
except (AttributeError, FieldError):
# Not every subexpression has an output_field which is fine
# to ignore.
pass
else:
if isinstance(output_field, bad_fields):
raise NotSupportedError(
"You cannot use Sum, Avg, StdDev, and Variance "
"aggregations on date/time fields in sqlite3 "
"since date/time is saved as text."
)
if (
isinstance(expression, models.Aggregate)
and expression.distinct
and len(expression.source_expressions) > 1
):
raise NotSupportedError(
"SQLite doesn't support DISTINCT on aggregate functions "
"accepting multiple arguments."
)
def date_extract_sql(self, lookup_type, sql, params):
"""
Support EXTRACT with a user-defined function django_date_extract()
that's registered in connect(). Use single quotes because this is a
string and could otherwise cause a collision with a field name.
"""
return f"django_date_extract(%s, {sql})", (lookup_type.lower(), *params)
def fetch_returned_insert_rows(self, cursor):
"""
Given a cursor object that has just performed an INSERT...RETURNING
statement into a table, return the list of returned data.
"""
return cursor.fetchall()
def format_for_duration_arithmetic(self, sql):
"""Do nothing since formatting is handled in the custom function."""
return sql
def date_trunc_sql(self, lookup_type, sql, params, tzname=None):
return f"django_date_trunc(%s, {sql}, %s, %s)", (
lookup_type.lower(),
*params,
*self._convert_tznames_to_sql(tzname),
)
def time_trunc_sql(self, lookup_type, sql, params, tzname=None):
return f"django_time_trunc(%s, {sql}, %s, %s)", (
lookup_type.lower(),
*params,
*self._convert_tznames_to_sql(tzname),
)
def _convert_tznames_to_sql(self, tzname):
if tzname and settings.USE_TZ:
return tzname, self.connection.timezone_name
return None, None
def datetime_cast_date_sql(self, sql, params, tzname):
return f"django_datetime_cast_date({sql}, %s, %s)", (
*params,
*self._convert_tznames_to_sql(tzname),
)
def datetime_cast_time_sql(self, sql, params, tzname):
return f"django_datetime_cast_time({sql}, %s, %s)", (
*params,
*self._convert_tznames_to_sql(tzname),
)
def datetime_extract_sql(self, lookup_type, sql, params, tzname):
return f"django_datetime_extract(%s, {sql}, %s, %s)", (
lookup_type.lower(),
*params,
*self._convert_tznames_to_sql(tzname),
)
def datetime_trunc_sql(self, lookup_type, sql, params, tzname):
return f"django_datetime_trunc(%s, {sql}, %s, %s)", (
lookup_type.lower(),
*params,
*self._convert_tznames_to_sql(tzname),
)
def time_extract_sql(self, lookup_type, sql, params):
return f"django_time_extract(%s, {sql})", (lookup_type.lower(), *params)
def pk_default_value(self):
return "NULL"
def _quote_params_for_last_executed_query(self, params):
"""
Only for last_executed_query! Don't use this to execute SQL queries!
"""
# This function is limited both by SQLITE_LIMIT_VARIABLE_NUMBER (the
# number of parameters, default = 999) and SQLITE_MAX_COLUMN (the
# number of return values, default = 2000). Since Python's sqlite3
# module doesn't expose the get_limit() C API, assume the default
# limits are in effect and split the work in batches if needed.
BATCH_SIZE = 999
if len(params) > BATCH_SIZE:
results = ()
for index in range(0, len(params), BATCH_SIZE):
chunk = params[index : index + BATCH_SIZE]
results += self._quote_params_for_last_executed_query(chunk)
return results
sql = "SELECT " + ", ".join(["QUOTE(?)"] * len(params))
# Bypass Django's wrappers and use the underlying sqlite3 connection
# to avoid logging this query - it would trigger infinite recursion.
cursor = self.connection.connection.cursor()
# Native sqlite3 cursors cannot be used as context managers.
try:
return cursor.execute(sql, params).fetchone()
finally:
cursor.close()
def last_executed_query(self, cursor, sql, params):
# Python substitutes parameters in Modules/_sqlite/cursor.c with:
# bind_parameters(state, self->statement, parameters);
# Unfortunately there is no way to reach self->statement from Python,
# so we quote and substitute parameters manually.
if params:
if isinstance(params, (list, tuple)):
params = self._quote_params_for_last_executed_query(params)
else:
values = tuple(params.values())
values = self._quote_params_for_last_executed_query(values)
params = dict(zip(params, values))
return sql % params
# For consistency with SQLiteCursorWrapper.execute(), just return sql
# when there are no parameters. See #13648 and #17158.
else:
return sql
def quote_name(self, name):
if name.startswith('"') and name.endswith('"'):
return name # Quoting once is enough.
return '"%s"' % name
def no_limit_value(self):
return -1
def __references_graph(self, table_name):
query = """
WITH tables AS (
SELECT %s name
UNION
SELECT sqlite_master.name
FROM sqlite_master
JOIN tables ON (sql REGEXP %s || tables.name || %s)
) SELECT name FROM tables;
"""
params = (
table_name,
r'(?i)\s+references\s+("|\')?',
r'("|\')?\s*\(',
)
with self.connection.cursor() as cursor:
results = cursor.execute(query, params)
return [row[0] for row in results.fetchall()]
@cached_property
def _references_graph(self):
# 512 is large enough to fit the ~330 tables (as of this writing) in
# Django's test suite.
return lru_cache(maxsize=512)(self.__references_graph)
def sql_flush(self, style, tables, *, reset_sequences=False, allow_cascade=False):
if tables and allow_cascade:
# Simulate TRUNCATE CASCADE by recursively collecting the tables
# referencing the tables to be flushed.
tables = set(
chain.from_iterable(self._references_graph(table) for table in tables)
)
sql = [
"%s %s %s;"
% (
style.SQL_KEYWORD("DELETE"),
style.SQL_KEYWORD("FROM"),
style.SQL_FIELD(self.quote_name(table)),
)
for table in tables
]
if reset_sequences:
sequences = [{"table": table} for table in tables]
sql.extend(self.sequence_reset_by_name_sql(style, sequences))
return sql
def sequence_reset_by_name_sql(self, style, sequences):
if not sequences:
return []
return [
"%s %s %s %s = 0 %s %s %s (%s);"
% (
style.SQL_KEYWORD("UPDATE"),
style.SQL_TABLE(self.quote_name("sqlite_sequence")),
style.SQL_KEYWORD("SET"),
style.SQL_FIELD(self.quote_name("seq")),
style.SQL_KEYWORD("WHERE"),
style.SQL_FIELD(self.quote_name("name")),
style.SQL_KEYWORD("IN"),
", ".join(
["'%s'" % sequence_info["table"] for sequence_info in sequences]
),
),
]
def adapt_datetimefield_value(self, value):
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, "resolve_expression"):
return value
# SQLite doesn't support tz-aware datetimes
if timezone.is_aware(value):
if settings.USE_TZ:
value = timezone.make_naive(value, self.connection.timezone)
else:
raise ValueError(
"SQLite backend does not support timezone-aware datetimes when "
"USE_TZ is False."
)
return str(value)
def adapt_timefield_value(self, value):
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, "resolve_expression"):
return value
# SQLite doesn't support tz-aware datetimes
if timezone.is_aware(value):
raise ValueError("SQLite backend does not support timezone-aware times.")
return str(value)
def get_db_converters(self, expression):
converters = super().get_db_converters(expression)
internal_type = expression.output_field.get_internal_type()
if internal_type == "DateTimeField":
converters.append(self.convert_datetimefield_value)
elif internal_type == "DateField":
converters.append(self.convert_datefield_value)
elif internal_type == "TimeField":
converters.append(self.convert_timefield_value)
elif internal_type == "DecimalField":
converters.append(self.get_decimalfield_converter(expression))
elif internal_type == "UUIDField":
converters.append(self.convert_uuidfield_value)
elif internal_type == "BooleanField":
converters.append(self.convert_booleanfield_value)
return converters
def convert_datetimefield_value(self, value, expression, connection):
if value is not None:
if not isinstance(value, datetime.datetime):
value = parse_datetime(value)
if settings.USE_TZ and not timezone.is_aware(value):
value = timezone.make_aware(value, self.connection.timezone)
return value
def convert_datefield_value(self, value, expression, connection):
if value is not None:
if not isinstance(value, datetime.date):
value = parse_date(value)
return value
def convert_timefield_value(self, value, expression, connection):
if value is not None:
if not isinstance(value, datetime.time):
value = parse_time(value)
return value
def get_decimalfield_converter(self, expression):
# SQLite stores only 15 significant digits. Digits coming from
# float inaccuracy must be removed.
create_decimal = decimal.Context(prec=15).create_decimal_from_float
if isinstance(expression, Col):
quantize_value = decimal.Decimal(1).scaleb(
-expression.output_field.decimal_places
)
def converter(value, expression, connection):
if value is not None:
return create_decimal(value).quantize(
quantize_value, context=expression.output_field.context
)
else:
def converter(value, expression, connection):
if value is not None:
return create_decimal(value)
return converter
def convert_uuidfield_value(self, value, expression, connection):
if value is not None:
value = uuid.UUID(value)
return value
def convert_booleanfield_value(self, value, expression, connection):
return bool(value) if value in (1, 0) else value
def bulk_insert_sql(self, fields, placeholder_rows):
placeholder_rows_sql = (", ".join(row) for row in placeholder_rows)
values_sql = ", ".join(f"({sql})" for sql in placeholder_rows_sql)
return f"VALUES {values_sql}"
def combine_expression(self, connector, sub_expressions):
# SQLite doesn't have a ^ operator, so use the user-defined POWER
# function that's registered in connect().
if connector == "^":
return "POWER(%s)" % ",".join(sub_expressions)
elif connector == "#":
return "BITXOR(%s)" % ",".join(sub_expressions)
return super().combine_expression(connector, sub_expressions)
def combine_duration_expression(self, connector, sub_expressions):
if connector not in ["+", "-", "*", "/"]:
raise DatabaseError("Invalid connector for timedelta: %s." % connector)
fn_params = ["'%s'" % connector] + sub_expressions
if len(fn_params) > 3:
raise ValueError("Too many params for timedelta operations.")
return "django_format_dtdelta(%s)" % ", ".join(fn_params)
def integer_field_range(self, internal_type):
# SQLite doesn't enforce any integer constraints
return (None, None)
def subtract_temporals(self, internal_type, lhs, rhs):
lhs_sql, lhs_params = lhs
rhs_sql, rhs_params = rhs
params = (*lhs_params, *rhs_params)
if internal_type == "TimeField":
return "django_time_diff(%s, %s)" % (lhs_sql, rhs_sql), params
return "django_timestamp_diff(%s, %s)" % (lhs_sql, rhs_sql), params
def insert_statement(self, on_conflict=None):
if on_conflict == OnConflict.IGNORE:
return "INSERT OR IGNORE INTO"
return super().insert_statement(on_conflict=on_conflict)
def return_insert_columns(self, fields):
# SQLite < 3.35 doesn't support an INSERT...RETURNING statement.
if not fields:
return "", ()
columns = [
"%s.%s"
% (
self.quote_name(field.model._meta.db_table),
self.quote_name(field.column),
)
for field in fields
]
return "RETURNING %s" % ", ".join(columns), ()
def on_conflict_suffix_sql(self, fields, on_conflict, update_fields, unique_fields):
if (
on_conflict == OnConflict.UPDATE
and self.connection.features.supports_update_conflicts_with_target
):
return "ON CONFLICT(%s) DO UPDATE SET %s" % (
", ".join(map(self.quote_name, unique_fields)),
", ".join(
[
f"{field} = EXCLUDED.{field}"
for field in map(self.quote_name, update_fields)
]
),
)
return super().on_conflict_suffix_sql(
fields,
on_conflict,
update_fields,
unique_fields,
)
|
castiel248/Convert
|
Lib/site-packages/django/db/backends/sqlite3/operations.py
|
Python
|
mit
| 16,961 |
import copy
from decimal import Decimal
from django.apps.registry import Apps
from django.db import NotSupportedError
from django.db.backends.base.schema import BaseDatabaseSchemaEditor
from django.db.backends.ddl_references import Statement
from django.db.backends.utils import strip_quotes
from django.db.models import UniqueConstraint
from django.db.transaction import atomic
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
sql_delete_table = "DROP TABLE %(table)s"
sql_create_fk = None
sql_create_inline_fk = (
"REFERENCES %(to_table)s (%(to_column)s) DEFERRABLE INITIALLY DEFERRED"
)
sql_create_column_inline_fk = sql_create_inline_fk
sql_delete_column = "ALTER TABLE %(table)s DROP COLUMN %(column)s"
sql_create_unique = "CREATE UNIQUE INDEX %(name)s ON %(table)s (%(columns)s)"
sql_delete_unique = "DROP INDEX %(name)s"
def __enter__(self):
# Some SQLite schema alterations need foreign key constraints to be
# disabled. Enforce it here for the duration of the schema edition.
if not self.connection.disable_constraint_checking():
raise NotSupportedError(
"SQLite schema editor cannot be used while foreign key "
"constraint checks are enabled. Make sure to disable them "
"before entering a transaction.atomic() context because "
"SQLite does not support disabling them in the middle of "
"a multi-statement transaction."
)
return super().__enter__()
def __exit__(self, exc_type, exc_value, traceback):
self.connection.check_constraints()
super().__exit__(exc_type, exc_value, traceback)
self.connection.enable_constraint_checking()
def quote_value(self, value):
# The backend "mostly works" without this function and there are use
# cases for compiling Python without the sqlite3 libraries (e.g.
# security hardening).
try:
import sqlite3
value = sqlite3.adapt(value)
except ImportError:
pass
except sqlite3.ProgrammingError:
pass
# Manual emulation of SQLite parameter quoting
if isinstance(value, bool):
return str(int(value))
elif isinstance(value, (Decimal, float, int)):
return str(value)
elif isinstance(value, str):
return "'%s'" % value.replace("'", "''")
elif value is None:
return "NULL"
elif isinstance(value, (bytes, bytearray, memoryview)):
# Bytes are only allowed for BLOB fields, encoded as string
# literals containing hexadecimal data and preceded by a single "X"
# character.
return "X'%s'" % value.hex()
else:
raise ValueError(
"Cannot quote parameter value %r of type %s" % (value, type(value))
)
def prepare_default(self, value):
return self.quote_value(value)
def _is_referenced_by_fk_constraint(
self, table_name, column_name=None, ignore_self=False
):
"""
Return whether or not the provided table name is referenced by another
one. If `column_name` is specified, only references pointing to that
column are considered. If `ignore_self` is True, self-referential
constraints are ignored.
"""
with self.connection.cursor() as cursor:
for other_table in self.connection.introspection.get_table_list(cursor):
if ignore_self and other_table.name == table_name:
continue
relations = self.connection.introspection.get_relations(
cursor, other_table.name
)
for constraint_column, constraint_table in relations.values():
if constraint_table == table_name and (
column_name is None or constraint_column == column_name
):
return True
return False
def alter_db_table(
self, model, old_db_table, new_db_table, disable_constraints=True
):
if (
not self.connection.features.supports_atomic_references_rename
and disable_constraints
and self._is_referenced_by_fk_constraint(old_db_table)
):
if self.connection.in_atomic_block:
raise NotSupportedError(
(
"Renaming the %r table while in a transaction is not "
"supported on SQLite < 3.26 because it would break referential "
"integrity. Try adding `atomic = False` to the Migration class."
)
% old_db_table
)
self.connection.enable_constraint_checking()
super().alter_db_table(model, old_db_table, new_db_table)
self.connection.disable_constraint_checking()
else:
super().alter_db_table(model, old_db_table, new_db_table)
def alter_field(self, model, old_field, new_field, strict=False):
if not self._field_should_be_altered(old_field, new_field):
return
old_field_name = old_field.name
table_name = model._meta.db_table
_, old_column_name = old_field.get_attname_column()
if (
new_field.name != old_field_name
and not self.connection.features.supports_atomic_references_rename
and self._is_referenced_by_fk_constraint(
table_name, old_column_name, ignore_self=True
)
):
if self.connection.in_atomic_block:
raise NotSupportedError(
(
"Renaming the %r.%r column while in a transaction is not "
"supported on SQLite < 3.26 because it would break referential "
"integrity. Try adding `atomic = False` to the Migration class."
)
% (model._meta.db_table, old_field_name)
)
with atomic(self.connection.alias):
super().alter_field(model, old_field, new_field, strict=strict)
# Follow SQLite's documented procedure for performing changes
# that don't affect the on-disk content.
# https://sqlite.org/lang_altertable.html#otheralter
with self.connection.cursor() as cursor:
schema_version = cursor.execute("PRAGMA schema_version").fetchone()[
0
]
cursor.execute("PRAGMA writable_schema = 1")
references_template = ' REFERENCES "%s" ("%%s") ' % table_name
new_column_name = new_field.get_attname_column()[1]
search = references_template % old_column_name
replacement = references_template % new_column_name
cursor.execute(
"UPDATE sqlite_master SET sql = replace(sql, %s, %s)",
(search, replacement),
)
cursor.execute("PRAGMA schema_version = %d" % (schema_version + 1))
cursor.execute("PRAGMA writable_schema = 0")
# The integrity check will raise an exception and rollback
# the transaction if the sqlite_master updates corrupt the
# database.
cursor.execute("PRAGMA integrity_check")
# Perform a VACUUM to refresh the database representation from
# the sqlite_master table.
with self.connection.cursor() as cursor:
cursor.execute("VACUUM")
else:
super().alter_field(model, old_field, new_field, strict=strict)
def _remake_table(
self, model, create_field=None, delete_field=None, alter_fields=None
):
"""
Shortcut to transform a model from old_model into new_model
This follows the correct procedure to perform non-rename or column
addition operations based on SQLite's documentation
https://www.sqlite.org/lang_altertable.html#caution
The essential steps are:
1. Create a table with the updated definition called "new__app_model"
2. Copy the data from the existing "app_model" table to the new table
3. Drop the "app_model" table
4. Rename the "new__app_model" table to "app_model"
5. Restore any index of the previous "app_model" table.
"""
# Self-referential fields must be recreated rather than copied from
# the old model to ensure their remote_field.field_name doesn't refer
# to an altered field.
def is_self_referential(f):
return f.is_relation and f.remote_field.model is model
# Work out the new fields dict / mapping
body = {
f.name: f.clone() if is_self_referential(f) else f
for f in model._meta.local_concrete_fields
}
# Since mapping might mix column names and default values,
# its values must be already quoted.
mapping = {
f.column: self.quote_name(f.column)
for f in model._meta.local_concrete_fields
}
# This maps field names (not columns) for things like unique_together
rename_mapping = {}
# If any of the new or altered fields is introducing a new PK,
# remove the old one
restore_pk_field = None
alter_fields = alter_fields or []
if getattr(create_field, "primary_key", False) or any(
getattr(new_field, "primary_key", False) for _, new_field in alter_fields
):
for name, field in list(body.items()):
if field.primary_key and not any(
# Do not remove the old primary key when an altered field
# that introduces a primary key is the same field.
name == new_field.name
for _, new_field in alter_fields
):
field.primary_key = False
restore_pk_field = field
if field.auto_created:
del body[name]
del mapping[field.column]
# Add in any created fields
if create_field:
body[create_field.name] = create_field
# Choose a default and insert it into the copy map
if not create_field.many_to_many and create_field.concrete:
mapping[create_field.column] = self.prepare_default(
self.effective_default(create_field),
)
# Add in any altered fields
for alter_field in alter_fields:
old_field, new_field = alter_field
body.pop(old_field.name, None)
mapping.pop(old_field.column, None)
body[new_field.name] = new_field
if old_field.null and not new_field.null:
case_sql = "coalesce(%(col)s, %(default)s)" % {
"col": self.quote_name(old_field.column),
"default": self.prepare_default(self.effective_default(new_field)),
}
mapping[new_field.column] = case_sql
else:
mapping[new_field.column] = self.quote_name(old_field.column)
rename_mapping[old_field.name] = new_field.name
# Remove any deleted fields
if delete_field:
del body[delete_field.name]
del mapping[delete_field.column]
# Remove any implicit M2M tables
if (
delete_field.many_to_many
and delete_field.remote_field.through._meta.auto_created
):
return self.delete_model(delete_field.remote_field.through)
# Work inside a new app registry
apps = Apps()
# Work out the new value of unique_together, taking renames into
# account
unique_together = [
[rename_mapping.get(n, n) for n in unique]
for unique in model._meta.unique_together
]
# Work out the new value for index_together, taking renames into
# account
index_together = [
[rename_mapping.get(n, n) for n in index]
for index in model._meta.index_together
]
indexes = model._meta.indexes
if delete_field:
indexes = [
index for index in indexes if delete_field.name not in index.fields
]
constraints = list(model._meta.constraints)
# Provide isolated instances of the fields to the new model body so
# that the existing model's internals aren't interfered with when
# the dummy model is constructed.
body_copy = copy.deepcopy(body)
# Construct a new model with the new fields to allow self referential
# primary key to resolve to. This model won't ever be materialized as a
# table and solely exists for foreign key reference resolution purposes.
# This wouldn't be required if the schema editor was operating on model
# states instead of rendered models.
meta_contents = {
"app_label": model._meta.app_label,
"db_table": model._meta.db_table,
"unique_together": unique_together,
"index_together": index_together,
"indexes": indexes,
"constraints": constraints,
"apps": apps,
}
meta = type("Meta", (), meta_contents)
body_copy["Meta"] = meta
body_copy["__module__"] = model.__module__
type(model._meta.object_name, model.__bases__, body_copy)
# Construct a model with a renamed table name.
body_copy = copy.deepcopy(body)
meta_contents = {
"app_label": model._meta.app_label,
"db_table": "new__%s" % strip_quotes(model._meta.db_table),
"unique_together": unique_together,
"index_together": index_together,
"indexes": indexes,
"constraints": constraints,
"apps": apps,
}
meta = type("Meta", (), meta_contents)
body_copy["Meta"] = meta
body_copy["__module__"] = model.__module__
new_model = type("New%s" % model._meta.object_name, model.__bases__, body_copy)
# Create a new table with the updated schema.
self.create_model(new_model)
# Copy data from the old table into the new table
self.execute(
"INSERT INTO %s (%s) SELECT %s FROM %s"
% (
self.quote_name(new_model._meta.db_table),
", ".join(self.quote_name(x) for x in mapping),
", ".join(mapping.values()),
self.quote_name(model._meta.db_table),
)
)
# Delete the old table to make way for the new
self.delete_model(model, handle_autom2m=False)
# Rename the new table to take way for the old
self.alter_db_table(
new_model,
new_model._meta.db_table,
model._meta.db_table,
disable_constraints=False,
)
# Run deferred SQL on correct table
for sql in self.deferred_sql:
self.execute(sql)
self.deferred_sql = []
# Fix any PK-removed field
if restore_pk_field:
restore_pk_field.primary_key = True
def delete_model(self, model, handle_autom2m=True):
if handle_autom2m:
super().delete_model(model)
else:
# Delete the table (and only that)
self.execute(
self.sql_delete_table
% {
"table": self.quote_name(model._meta.db_table),
}
)
# Remove all deferred statements referencing the deleted table.
for sql in list(self.deferred_sql):
if isinstance(sql, Statement) and sql.references_table(
model._meta.db_table
):
self.deferred_sql.remove(sql)
def add_field(self, model, field):
"""Create a field on a model."""
# Special-case implicit M2M tables.
if field.many_to_many and field.remote_field.through._meta.auto_created:
self.create_model(field.remote_field.through)
elif (
# Primary keys and unique fields are not supported in ALTER TABLE
# ADD COLUMN.
field.primary_key
or field.unique
or
# Fields with default values cannot by handled by ALTER TABLE ADD
# COLUMN statement because DROP DEFAULT is not supported in
# ALTER TABLE.
not field.null
or self.effective_default(field) is not None
):
self._remake_table(model, create_field=field)
else:
super().add_field(model, field)
def remove_field(self, model, field):
"""
Remove a field from a model. Usually involves deleting a column,
but for M2Ms may involve deleting a table.
"""
# M2M fields are a special case
if field.many_to_many:
# For implicit M2M tables, delete the auto-created table
if field.remote_field.through._meta.auto_created:
self.delete_model(field.remote_field.through)
# For explicit "through" M2M fields, do nothing
elif (
self.connection.features.can_alter_table_drop_column
# Primary keys, unique fields, indexed fields, and foreign keys are
# not supported in ALTER TABLE DROP COLUMN.
and not field.primary_key
and not field.unique
and not field.db_index
and not (field.remote_field and field.db_constraint)
):
super().remove_field(model, field)
# For everything else, remake.
else:
# It might not actually have a column behind it
if field.db_parameters(connection=self.connection)["type"] is None:
return
self._remake_table(model, delete_field=field)
def _alter_field(
self,
model,
old_field,
new_field,
old_type,
new_type,
old_db_params,
new_db_params,
strict=False,
):
"""Perform a "physical" (non-ManyToMany) field update."""
# Use "ALTER TABLE ... RENAME COLUMN" if only the column name
# changed and there aren't any constraints.
if (
self.connection.features.can_alter_table_rename_column
and old_field.column != new_field.column
and self.column_sql(model, old_field) == self.column_sql(model, new_field)
and not (
old_field.remote_field
and old_field.db_constraint
or new_field.remote_field
and new_field.db_constraint
)
):
return self.execute(
self._rename_field_sql(
model._meta.db_table, old_field, new_field, new_type
)
)
# Alter by remaking table
self._remake_table(model, alter_fields=[(old_field, new_field)])
# Rebuild tables with FKs pointing to this field.
old_collation = old_db_params.get("collation")
new_collation = new_db_params.get("collation")
if new_field.unique and (
old_type != new_type or old_collation != new_collation
):
related_models = set()
opts = new_field.model._meta
for remote_field in opts.related_objects:
# Ignore self-relationship since the table was already rebuilt.
if remote_field.related_model == model:
continue
if not remote_field.many_to_many:
if remote_field.field_name == new_field.name:
related_models.add(remote_field.related_model)
elif new_field.primary_key and remote_field.through._meta.auto_created:
related_models.add(remote_field.through)
if new_field.primary_key:
for many_to_many in opts.many_to_many:
# Ignore self-relationship since the table was already rebuilt.
if many_to_many.related_model == model:
continue
if many_to_many.remote_field.through._meta.auto_created:
related_models.add(many_to_many.remote_field.through)
for related_model in related_models:
self._remake_table(related_model)
def _alter_many_to_many(self, model, old_field, new_field, strict):
"""Alter M2Ms to repoint their to= endpoints."""
if (
old_field.remote_field.through._meta.db_table
== new_field.remote_field.through._meta.db_table
):
# The field name didn't change, but some options did, so we have to
# propagate this altering.
self._remake_table(
old_field.remote_field.through,
alter_fields=[
(
# The field that points to the target model is needed,
# so that table can be remade with the new m2m field -
# this is m2m_reverse_field_name().
old_field.remote_field.through._meta.get_field(
old_field.m2m_reverse_field_name()
),
new_field.remote_field.through._meta.get_field(
new_field.m2m_reverse_field_name()
),
),
(
# The field that points to the model itself is needed,
# so that table can be remade with the new self field -
# this is m2m_field_name().
old_field.remote_field.through._meta.get_field(
old_field.m2m_field_name()
),
new_field.remote_field.through._meta.get_field(
new_field.m2m_field_name()
),
),
],
)
return
# Make a new through table
self.create_model(new_field.remote_field.through)
# Copy the data across
self.execute(
"INSERT INTO %s (%s) SELECT %s FROM %s"
% (
self.quote_name(new_field.remote_field.through._meta.db_table),
", ".join(
[
"id",
new_field.m2m_column_name(),
new_field.m2m_reverse_name(),
]
),
", ".join(
[
"id",
old_field.m2m_column_name(),
old_field.m2m_reverse_name(),
]
),
self.quote_name(old_field.remote_field.through._meta.db_table),
)
)
# Delete the old through table
self.delete_model(old_field.remote_field.through)
def add_constraint(self, model, constraint):
if isinstance(constraint, UniqueConstraint) and (
constraint.condition
or constraint.contains_expressions
or constraint.include
or constraint.deferrable
):
super().add_constraint(model, constraint)
else:
self._remake_table(model)
def remove_constraint(self, model, constraint):
if isinstance(constraint, UniqueConstraint) and (
constraint.condition
or constraint.contains_expressions
or constraint.include
or constraint.deferrable
):
super().remove_constraint(model, constraint)
else:
self._remake_table(model)
def _collate_sql(self, collation):
return "COLLATE " + collation
|
castiel248/Convert
|
Lib/site-packages/django/db/backends/sqlite3/schema.py
|
Python
|
mit
| 24,430 |
import datetime
import decimal
import functools
import logging
import time
from contextlib import contextmanager
from django.db import NotSupportedError
from django.utils.crypto import md5
from django.utils.dateparse import parse_time
logger = logging.getLogger("django.db.backends")
class CursorWrapper:
def __init__(self, cursor, db):
self.cursor = cursor
self.db = db
WRAP_ERROR_ATTRS = frozenset(["fetchone", "fetchmany", "fetchall", "nextset"])
def __getattr__(self, attr):
cursor_attr = getattr(self.cursor, attr)
if attr in CursorWrapper.WRAP_ERROR_ATTRS:
return self.db.wrap_database_errors(cursor_attr)
else:
return cursor_attr
def __iter__(self):
with self.db.wrap_database_errors:
yield from self.cursor
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
# Close instead of passing through to avoid backend-specific behavior
# (#17671). Catch errors liberally because errors in cleanup code
# aren't useful.
try:
self.close()
except self.db.Database.Error:
pass
# The following methods cannot be implemented in __getattr__, because the
# code must run when the method is invoked, not just when it is accessed.
def callproc(self, procname, params=None, kparams=None):
# Keyword parameters for callproc aren't supported in PEP 249, but the
# database driver may support them (e.g. cx_Oracle).
if kparams is not None and not self.db.features.supports_callproc_kwargs:
raise NotSupportedError(
"Keyword parameters for callproc are not supported on this "
"database backend."
)
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
if params is None and kparams is None:
return self.cursor.callproc(procname)
elif kparams is None:
return self.cursor.callproc(procname, params)
else:
params = params or ()
return self.cursor.callproc(procname, params, kparams)
def execute(self, sql, params=None):
return self._execute_with_wrappers(
sql, params, many=False, executor=self._execute
)
def executemany(self, sql, param_list):
return self._execute_with_wrappers(
sql, param_list, many=True, executor=self._executemany
)
def _execute_with_wrappers(self, sql, params, many, executor):
context = {"connection": self.db, "cursor": self}
for wrapper in reversed(self.db.execute_wrappers):
executor = functools.partial(wrapper, executor)
return executor(sql, params, many, context)
def _execute(self, sql, params, *ignored_wrapper_args):
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
if params is None:
# params default might be backend specific.
return self.cursor.execute(sql)
else:
return self.cursor.execute(sql, params)
def _executemany(self, sql, param_list, *ignored_wrapper_args):
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
return self.cursor.executemany(sql, param_list)
class CursorDebugWrapper(CursorWrapper):
# XXX callproc isn't instrumented at this time.
def execute(self, sql, params=None):
with self.debug_sql(sql, params, use_last_executed_query=True):
return super().execute(sql, params)
def executemany(self, sql, param_list):
with self.debug_sql(sql, param_list, many=True):
return super().executemany(sql, param_list)
@contextmanager
def debug_sql(
self, sql=None, params=None, use_last_executed_query=False, many=False
):
start = time.monotonic()
try:
yield
finally:
stop = time.monotonic()
duration = stop - start
if use_last_executed_query:
sql = self.db.ops.last_executed_query(self.cursor, sql, params)
try:
times = len(params) if many else ""
except TypeError:
# params could be an iterator.
times = "?"
self.db.queries_log.append(
{
"sql": "%s times: %s" % (times, sql) if many else sql,
"time": "%.3f" % duration,
}
)
logger.debug(
"(%.3f) %s; args=%s; alias=%s",
duration,
sql,
params,
self.db.alias,
extra={
"duration": duration,
"sql": sql,
"params": params,
"alias": self.db.alias,
},
)
@contextmanager
def debug_transaction(connection, sql):
start = time.monotonic()
try:
yield
finally:
if connection.queries_logged:
stop = time.monotonic()
duration = stop - start
connection.queries_log.append(
{
"sql": "%s" % sql,
"time": "%.3f" % duration,
}
)
logger.debug(
"(%.3f) %s; args=%s; alias=%s",
duration,
sql,
None,
connection.alias,
extra={
"duration": duration,
"sql": sql,
"alias": connection.alias,
},
)
def split_tzname_delta(tzname):
"""
Split a time zone name into a 3-tuple of (name, sign, offset).
"""
for sign in ["+", "-"]:
if sign in tzname:
name, offset = tzname.rsplit(sign, 1)
if offset and parse_time(offset):
return name, sign, offset
return tzname, None, None
###############################################
# Converters from database (string) to Python #
###############################################
def typecast_date(s):
return (
datetime.date(*map(int, s.split("-"))) if s else None
) # return None if s is null
def typecast_time(s): # does NOT store time zone information
if not s:
return None
hour, minutes, seconds = s.split(":")
if "." in seconds: # check whether seconds have a fractional part
seconds, microseconds = seconds.split(".")
else:
microseconds = "0"
return datetime.time(
int(hour), int(minutes), int(seconds), int((microseconds + "000000")[:6])
)
def typecast_timestamp(s): # does NOT store time zone information
# "2005-07-29 15:48:00.590358-05"
# "2005-07-29 09:56:00-05"
if not s:
return None
if " " not in s:
return typecast_date(s)
d, t = s.split()
# Remove timezone information.
if "-" in t:
t, _ = t.split("-", 1)
elif "+" in t:
t, _ = t.split("+", 1)
dates = d.split("-")
times = t.split(":")
seconds = times[2]
if "." in seconds: # check whether seconds have a fractional part
seconds, microseconds = seconds.split(".")
else:
microseconds = "0"
return datetime.datetime(
int(dates[0]),
int(dates[1]),
int(dates[2]),
int(times[0]),
int(times[1]),
int(seconds),
int((microseconds + "000000")[:6]),
)
###############################################
# Converters from Python to database (string) #
###############################################
def split_identifier(identifier):
"""
Split an SQL identifier into a two element tuple of (namespace, name).
The identifier could be a table, column, or sequence name might be prefixed
by a namespace.
"""
try:
namespace, name = identifier.split('"."')
except ValueError:
namespace, name = "", identifier
return namespace.strip('"'), name.strip('"')
def truncate_name(identifier, length=None, hash_len=4):
"""
Shorten an SQL identifier to a repeatable mangled version with the given
length.
If a quote stripped name contains a namespace, e.g. USERNAME"."TABLE,
truncate the table portion only.
"""
namespace, name = split_identifier(identifier)
if length is None or len(name) <= length:
return identifier
digest = names_digest(name, length=hash_len)
return "%s%s%s" % (
'%s"."' % namespace if namespace else "",
name[: length - hash_len],
digest,
)
def names_digest(*args, length):
"""
Generate a 32-bit digest of a set of arguments that can be used to shorten
identifying names.
"""
h = md5(usedforsecurity=False)
for arg in args:
h.update(arg.encode())
return h.hexdigest()[:length]
def format_number(value, max_digits, decimal_places):
"""
Format a number into a string with the requisite number of digits and
decimal places.
"""
if value is None:
return None
context = decimal.getcontext().copy()
if max_digits is not None:
context.prec = max_digits
if decimal_places is not None:
value = value.quantize(
decimal.Decimal(1).scaleb(-decimal_places), context=context
)
else:
context.traps[decimal.Rounded] = 1
value = context.create_decimal(value)
return "{:f}".format(value)
def strip_quotes(table_name):
"""
Strip quotes off of quoted table names to make them safe for use in index
names, sequence names, etc. For example '"USER"."TABLE"' (an Oracle naming
scheme) becomes 'USER"."TABLE'.
"""
has_quotes = table_name.startswith('"') and table_name.endswith('"')
return table_name[1:-1] if has_quotes else table_name
|
castiel248/Convert
|
Lib/site-packages/django/db/backends/utils.py
|
Python
|
mit
| 10,002 |
from .migration import Migration, swappable_dependency # NOQA
from .operations import * # NOQA
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/__init__.py
|
Python
|
mit
| 97 |
import functools
import re
from collections import defaultdict
from itertools import chain
from django.conf import settings
from django.db import models
from django.db.migrations import operations
from django.db.migrations.migration import Migration
from django.db.migrations.operations.models import AlterModelOptions
from django.db.migrations.optimizer import MigrationOptimizer
from django.db.migrations.questioner import MigrationQuestioner
from django.db.migrations.utils import (
COMPILED_REGEX_TYPE,
RegexObject,
resolve_relation,
)
from django.utils.topological_sort import stable_topological_sort
class MigrationAutodetector:
"""
Take a pair of ProjectStates and compare them to see what the first would
need doing to make it match the second (the second usually being the
project's current state).
Note that this naturally operates on entire projects at a time,
as it's likely that changes interact (for example, you can't
add a ForeignKey without having a migration to add the table it
depends on first). A user interface may offer single-app usage
if it wishes, with the caveat that it may not always be possible.
"""
def __init__(self, from_state, to_state, questioner=None):
self.from_state = from_state
self.to_state = to_state
self.questioner = questioner or MigrationQuestioner()
self.existing_apps = {app for app, model in from_state.models}
def changes(self, graph, trim_to_apps=None, convert_apps=None, migration_name=None):
"""
Main entry point to produce a list of applicable changes.
Take a graph to base names on and an optional set of apps
to try and restrict to (restriction is not guaranteed)
"""
changes = self._detect_changes(convert_apps, graph)
changes = self.arrange_for_graph(changes, graph, migration_name)
if trim_to_apps:
changes = self._trim_to_apps(changes, trim_to_apps)
return changes
def deep_deconstruct(self, obj):
"""
Recursive deconstruction for a field and its arguments.
Used for full comparison for rename/alter; sometimes a single-level
deconstruction will not compare correctly.
"""
if isinstance(obj, list):
return [self.deep_deconstruct(value) for value in obj]
elif isinstance(obj, tuple):
return tuple(self.deep_deconstruct(value) for value in obj)
elif isinstance(obj, dict):
return {key: self.deep_deconstruct(value) for key, value in obj.items()}
elif isinstance(obj, functools.partial):
return (
obj.func,
self.deep_deconstruct(obj.args),
self.deep_deconstruct(obj.keywords),
)
elif isinstance(obj, COMPILED_REGEX_TYPE):
return RegexObject(obj)
elif isinstance(obj, type):
# If this is a type that implements 'deconstruct' as an instance method,
# avoid treating this as being deconstructible itself - see #22951
return obj
elif hasattr(obj, "deconstruct"):
deconstructed = obj.deconstruct()
if isinstance(obj, models.Field):
# we have a field which also returns a name
deconstructed = deconstructed[1:]
path, args, kwargs = deconstructed
return (
path,
[self.deep_deconstruct(value) for value in args],
{key: self.deep_deconstruct(value) for key, value in kwargs.items()},
)
else:
return obj
def only_relation_agnostic_fields(self, fields):
"""
Return a definition of the fields that ignores field names and
what related fields actually relate to. Used for detecting renames (as
the related fields change during renames).
"""
fields_def = []
for name, field in sorted(fields.items()):
deconstruction = self.deep_deconstruct(field)
if field.remote_field and field.remote_field.model:
deconstruction[2].pop("to", None)
fields_def.append(deconstruction)
return fields_def
def _detect_changes(self, convert_apps=None, graph=None):
"""
Return a dict of migration plans which will achieve the
change from from_state to to_state. The dict has app labels
as keys and a list of migrations as values.
The resulting migrations aren't specially named, but the names
do matter for dependencies inside the set.
convert_apps is the list of apps to convert to use migrations
(i.e. to make initial migrations for, in the usual case)
graph is an optional argument that, if provided, can help improve
dependency generation and avoid potential circular dependencies.
"""
# The first phase is generating all the operations for each app
# and gathering them into a big per-app list.
# Then go through that list, order it, and split into migrations to
# resolve dependencies caused by M2Ms and FKs.
self.generated_operations = {}
self.altered_indexes = {}
self.altered_constraints = {}
self.renamed_fields = {}
# Prepare some old/new state and model lists, separating
# proxy models and ignoring unmigrated apps.
self.old_model_keys = set()
self.old_proxy_keys = set()
self.old_unmanaged_keys = set()
self.new_model_keys = set()
self.new_proxy_keys = set()
self.new_unmanaged_keys = set()
for (app_label, model_name), model_state in self.from_state.models.items():
if not model_state.options.get("managed", True):
self.old_unmanaged_keys.add((app_label, model_name))
elif app_label not in self.from_state.real_apps:
if model_state.options.get("proxy"):
self.old_proxy_keys.add((app_label, model_name))
else:
self.old_model_keys.add((app_label, model_name))
for (app_label, model_name), model_state in self.to_state.models.items():
if not model_state.options.get("managed", True):
self.new_unmanaged_keys.add((app_label, model_name))
elif app_label not in self.from_state.real_apps or (
convert_apps and app_label in convert_apps
):
if model_state.options.get("proxy"):
self.new_proxy_keys.add((app_label, model_name))
else:
self.new_model_keys.add((app_label, model_name))
self.from_state.resolve_fields_and_relations()
self.to_state.resolve_fields_and_relations()
# Renames have to come first
self.generate_renamed_models()
# Prepare lists of fields and generate through model map
self._prepare_field_lists()
self._generate_through_model_map()
# Generate non-rename model operations
self.generate_deleted_models()
self.generate_created_models()
self.generate_deleted_proxies()
self.generate_created_proxies()
self.generate_altered_options()
self.generate_altered_managers()
self.generate_altered_db_table_comment()
# Create the renamed fields and store them in self.renamed_fields.
# They are used by create_altered_indexes(), generate_altered_fields(),
# generate_removed_altered_index/unique_together(), and
# generate_altered_index/unique_together().
self.create_renamed_fields()
# Create the altered indexes and store them in self.altered_indexes.
# This avoids the same computation in generate_removed_indexes()
# and generate_added_indexes().
self.create_altered_indexes()
self.create_altered_constraints()
# Generate index removal operations before field is removed
self.generate_removed_constraints()
self.generate_removed_indexes()
# Generate field renaming operations.
self.generate_renamed_fields()
self.generate_renamed_indexes()
# Generate removal of foo together.
self.generate_removed_altered_unique_together()
self.generate_removed_altered_index_together() # RemovedInDjango51Warning.
# Generate field operations.
self.generate_removed_fields()
self.generate_added_fields()
self.generate_altered_fields()
self.generate_altered_order_with_respect_to()
self.generate_altered_unique_together()
self.generate_altered_index_together() # RemovedInDjango51Warning.
self.generate_added_indexes()
self.generate_added_constraints()
self.generate_altered_db_table()
self._sort_migrations()
self._build_migration_list(graph)
self._optimize_migrations()
return self.migrations
def _prepare_field_lists(self):
"""
Prepare field lists and a list of the fields that used through models
in the old state so dependencies can be made from the through model
deletion to the field that uses it.
"""
self.kept_model_keys = self.old_model_keys & self.new_model_keys
self.kept_proxy_keys = self.old_proxy_keys & self.new_proxy_keys
self.kept_unmanaged_keys = self.old_unmanaged_keys & self.new_unmanaged_keys
self.through_users = {}
self.old_field_keys = {
(app_label, model_name, field_name)
for app_label, model_name in self.kept_model_keys
for field_name in self.from_state.models[
app_label, self.renamed_models.get((app_label, model_name), model_name)
].fields
}
self.new_field_keys = {
(app_label, model_name, field_name)
for app_label, model_name in self.kept_model_keys
for field_name in self.to_state.models[app_label, model_name].fields
}
def _generate_through_model_map(self):
"""Through model map generation."""
for app_label, model_name in sorted(self.old_model_keys):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
for field_name, field in old_model_state.fields.items():
if hasattr(field, "remote_field") and getattr(
field.remote_field, "through", None
):
through_key = resolve_relation(
field.remote_field.through, app_label, model_name
)
self.through_users[through_key] = (
app_label,
old_model_name,
field_name,
)
@staticmethod
def _resolve_dependency(dependency):
"""
Return the resolved dependency and a boolean denoting whether or not
it was swappable.
"""
if dependency[0] != "__setting__":
return dependency, False
resolved_app_label, resolved_object_name = getattr(
settings, dependency[1]
).split(".")
return (resolved_app_label, resolved_object_name.lower()) + dependency[2:], True
def _build_migration_list(self, graph=None):
"""
Chop the lists of operations up into migrations with dependencies on
each other. Do this by going through an app's list of operations until
one is found that has an outgoing dependency that isn't in another
app's migration yet (hasn't been chopped off its list). Then chop off
the operations before it into a migration and move onto the next app.
If the loops completes without doing anything, there's a circular
dependency (which _should_ be impossible as the operations are
all split at this point so they can't depend and be depended on).
"""
self.migrations = {}
num_ops = sum(len(x) for x in self.generated_operations.values())
chop_mode = False
while num_ops:
# On every iteration, we step through all the apps and see if there
# is a completed set of operations.
# If we find that a subset of the operations are complete we can
# try to chop it off from the rest and continue, but we only
# do this if we've already been through the list once before
# without any chopping and nothing has changed.
for app_label in sorted(self.generated_operations):
chopped = []
dependencies = set()
for operation in list(self.generated_operations[app_label]):
deps_satisfied = True
operation_dependencies = set()
for dep in operation._auto_deps:
# Temporarily resolve the swappable dependency to
# prevent circular references. While keeping the
# dependency checks on the resolved model, add the
# swappable dependencies.
original_dep = dep
dep, is_swappable_dep = self._resolve_dependency(dep)
if dep[0] != app_label:
# External app dependency. See if it's not yet
# satisfied.
for other_operation in self.generated_operations.get(
dep[0], []
):
if self.check_dependency(other_operation, dep):
deps_satisfied = False
break
if not deps_satisfied:
break
else:
if is_swappable_dep:
operation_dependencies.add(
(original_dep[0], original_dep[1])
)
elif dep[0] in self.migrations:
operation_dependencies.add(
(dep[0], self.migrations[dep[0]][-1].name)
)
else:
# If we can't find the other app, we add a
# first/last dependency, but only if we've
# already been through once and checked
# everything.
if chop_mode:
# If the app already exists, we add a
# dependency on the last migration, as
# we don't know which migration
# contains the target field. If it's
# not yet migrated or has no
# migrations, we use __first__.
if graph and graph.leaf_nodes(dep[0]):
operation_dependencies.add(
graph.leaf_nodes(dep[0])[0]
)
else:
operation_dependencies.add(
(dep[0], "__first__")
)
else:
deps_satisfied = False
if deps_satisfied:
chopped.append(operation)
dependencies.update(operation_dependencies)
del self.generated_operations[app_label][0]
else:
break
# Make a migration! Well, only if there's stuff to put in it
if dependencies or chopped:
if not self.generated_operations[app_label] or chop_mode:
subclass = type(
"Migration",
(Migration,),
{"operations": [], "dependencies": []},
)
instance = subclass(
"auto_%i" % (len(self.migrations.get(app_label, [])) + 1),
app_label,
)
instance.dependencies = list(dependencies)
instance.operations = chopped
instance.initial = app_label not in self.existing_apps
self.migrations.setdefault(app_label, []).append(instance)
chop_mode = False
else:
self.generated_operations[app_label] = (
chopped + self.generated_operations[app_label]
)
new_num_ops = sum(len(x) for x in self.generated_operations.values())
if new_num_ops == num_ops:
if not chop_mode:
chop_mode = True
else:
raise ValueError(
"Cannot resolve operation dependencies: %r"
% self.generated_operations
)
num_ops = new_num_ops
def _sort_migrations(self):
"""
Reorder to make things possible. Reordering may be needed so FKs work
nicely inside the same app.
"""
for app_label, ops in sorted(self.generated_operations.items()):
# construct a dependency graph for intra-app dependencies
dependency_graph = {op: set() for op in ops}
for op in ops:
for dep in op._auto_deps:
# Resolve intra-app dependencies to handle circular
# references involving a swappable model.
dep = self._resolve_dependency(dep)[0]
if dep[0] == app_label:
for op2 in ops:
if self.check_dependency(op2, dep):
dependency_graph[op].add(op2)
# we use a stable sort for deterministic tests & general behavior
self.generated_operations[app_label] = stable_topological_sort(
ops, dependency_graph
)
def _optimize_migrations(self):
# Add in internal dependencies among the migrations
for app_label, migrations in self.migrations.items():
for m1, m2 in zip(migrations, migrations[1:]):
m2.dependencies.append((app_label, m1.name))
# De-dupe dependencies
for migrations in self.migrations.values():
for migration in migrations:
migration.dependencies = list(set(migration.dependencies))
# Optimize migrations
for app_label, migrations in self.migrations.items():
for migration in migrations:
migration.operations = MigrationOptimizer().optimize(
migration.operations, app_label
)
def check_dependency(self, operation, dependency):
"""
Return True if the given operation depends on the given dependency,
False otherwise.
"""
# Created model
if dependency[2] is None and dependency[3] is True:
return (
isinstance(operation, operations.CreateModel)
and operation.name_lower == dependency[1].lower()
)
# Created field
elif dependency[2] is not None and dependency[3] is True:
return (
isinstance(operation, operations.CreateModel)
and operation.name_lower == dependency[1].lower()
and any(dependency[2] == x for x, y in operation.fields)
) or (
isinstance(operation, operations.AddField)
and operation.model_name_lower == dependency[1].lower()
and operation.name_lower == dependency[2].lower()
)
# Removed field
elif dependency[2] is not None and dependency[3] is False:
return (
isinstance(operation, operations.RemoveField)
and operation.model_name_lower == dependency[1].lower()
and operation.name_lower == dependency[2].lower()
)
# Removed model
elif dependency[2] is None and dependency[3] is False:
return (
isinstance(operation, operations.DeleteModel)
and operation.name_lower == dependency[1].lower()
)
# Field being altered
elif dependency[2] is not None and dependency[3] == "alter":
return (
isinstance(operation, operations.AlterField)
and operation.model_name_lower == dependency[1].lower()
and operation.name_lower == dependency[2].lower()
)
# order_with_respect_to being unset for a field
elif dependency[2] is not None and dependency[3] == "order_wrt_unset":
return (
isinstance(operation, operations.AlterOrderWithRespectTo)
and operation.name_lower == dependency[1].lower()
and (operation.order_with_respect_to or "").lower()
!= dependency[2].lower()
)
# Field is removed and part of an index/unique_together
elif dependency[2] is not None and dependency[3] == "foo_together_change":
return (
isinstance(
operation,
(operations.AlterUniqueTogether, operations.AlterIndexTogether),
)
and operation.name_lower == dependency[1].lower()
)
# Unknown dependency. Raise an error.
else:
raise ValueError("Can't handle dependency %r" % (dependency,))
def add_operation(self, app_label, operation, dependencies=None, beginning=False):
# Dependencies are
# (app_label, model_name, field_name, create/delete as True/False)
operation._auto_deps = dependencies or []
if beginning:
self.generated_operations.setdefault(app_label, []).insert(0, operation)
else:
self.generated_operations.setdefault(app_label, []).append(operation)
def swappable_first_key(self, item):
"""
Place potential swappable models first in lists of created models (only
real way to solve #22783).
"""
try:
model_state = self.to_state.models[item]
base_names = {
base if isinstance(base, str) else base.__name__
for base in model_state.bases
}
string_version = "%s.%s" % (item[0], item[1])
if (
model_state.options.get("swappable")
or "AbstractUser" in base_names
or "AbstractBaseUser" in base_names
or settings.AUTH_USER_MODEL.lower() == string_version.lower()
):
return ("___" + item[0], "___" + item[1])
except LookupError:
pass
return item
def generate_renamed_models(self):
"""
Find any renamed models, generate the operations for them, and remove
the old entry from the model lists. Must be run before other
model-level generation.
"""
self.renamed_models = {}
self.renamed_models_rel = {}
added_models = self.new_model_keys - self.old_model_keys
for app_label, model_name in sorted(added_models):
model_state = self.to_state.models[app_label, model_name]
model_fields_def = self.only_relation_agnostic_fields(model_state.fields)
removed_models = self.old_model_keys - self.new_model_keys
for rem_app_label, rem_model_name in removed_models:
if rem_app_label == app_label:
rem_model_state = self.from_state.models[
rem_app_label, rem_model_name
]
rem_model_fields_def = self.only_relation_agnostic_fields(
rem_model_state.fields
)
if model_fields_def == rem_model_fields_def:
if self.questioner.ask_rename_model(
rem_model_state, model_state
):
dependencies = []
fields = list(model_state.fields.values()) + [
field.remote_field
for relations in self.to_state.relations[
app_label, model_name
].values()
for field in relations.values()
]
for field in fields:
if field.is_relation:
dependencies.extend(
self._get_dependencies_for_foreign_key(
app_label,
model_name,
field,
self.to_state,
)
)
self.add_operation(
app_label,
operations.RenameModel(
old_name=rem_model_state.name,
new_name=model_state.name,
),
dependencies=dependencies,
)
self.renamed_models[app_label, model_name] = rem_model_name
renamed_models_rel_key = "%s.%s" % (
rem_model_state.app_label,
rem_model_state.name_lower,
)
self.renamed_models_rel[
renamed_models_rel_key
] = "%s.%s" % (
model_state.app_label,
model_state.name_lower,
)
self.old_model_keys.remove((rem_app_label, rem_model_name))
self.old_model_keys.add((app_label, model_name))
break
def generate_created_models(self):
"""
Find all new models (both managed and unmanaged) and make create
operations for them as well as separate operations to create any
foreign key or M2M relationships (these are optimized later, if
possible).
Defer any model options that refer to collections of fields that might
be deferred (e.g. unique_together, index_together).
"""
old_keys = self.old_model_keys | self.old_unmanaged_keys
added_models = self.new_model_keys - old_keys
added_unmanaged_models = self.new_unmanaged_keys - old_keys
all_added_models = chain(
sorted(added_models, key=self.swappable_first_key, reverse=True),
sorted(added_unmanaged_models, key=self.swappable_first_key, reverse=True),
)
for app_label, model_name in all_added_models:
model_state = self.to_state.models[app_label, model_name]
# Gather related fields
related_fields = {}
primary_key_rel = None
for field_name, field in model_state.fields.items():
if field.remote_field:
if field.remote_field.model:
if field.primary_key:
primary_key_rel = field.remote_field.model
elif not field.remote_field.parent_link:
related_fields[field_name] = field
if getattr(field.remote_field, "through", None):
related_fields[field_name] = field
# Are there indexes/unique|index_together to defer?
indexes = model_state.options.pop("indexes")
constraints = model_state.options.pop("constraints")
unique_together = model_state.options.pop("unique_together", None)
# RemovedInDjango51Warning.
index_together = model_state.options.pop("index_together", None)
order_with_respect_to = model_state.options.pop(
"order_with_respect_to", None
)
# Depend on the deletion of any possible proxy version of us
dependencies = [
(app_label, model_name, None, False),
]
# Depend on all bases
for base in model_state.bases:
if isinstance(base, str) and "." in base:
base_app_label, base_name = base.split(".", 1)
dependencies.append((base_app_label, base_name, None, True))
# Depend on the removal of base fields if the new model has
# a field with the same name.
old_base_model_state = self.from_state.models.get(
(base_app_label, base_name)
)
new_base_model_state = self.to_state.models.get(
(base_app_label, base_name)
)
if old_base_model_state and new_base_model_state:
removed_base_fields = (
set(old_base_model_state.fields)
.difference(
new_base_model_state.fields,
)
.intersection(model_state.fields)
)
for removed_base_field in removed_base_fields:
dependencies.append(
(base_app_label, base_name, removed_base_field, False)
)
# Depend on the other end of the primary key if it's a relation
if primary_key_rel:
dependencies.append(
resolve_relation(
primary_key_rel,
app_label,
model_name,
)
+ (None, True)
)
# Generate creation operation
self.add_operation(
app_label,
operations.CreateModel(
name=model_state.name,
fields=[
d
for d in model_state.fields.items()
if d[0] not in related_fields
],
options=model_state.options,
bases=model_state.bases,
managers=model_state.managers,
),
dependencies=dependencies,
beginning=True,
)
# Don't add operations which modify the database for unmanaged models
if not model_state.options.get("managed", True):
continue
# Generate operations for each related field
for name, field in sorted(related_fields.items()):
dependencies = self._get_dependencies_for_foreign_key(
app_label,
model_name,
field,
self.to_state,
)
# Depend on our own model being created
dependencies.append((app_label, model_name, None, True))
# Make operation
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=name,
field=field,
),
dependencies=list(set(dependencies)),
)
# Generate other opns
if order_with_respect_to:
self.add_operation(
app_label,
operations.AlterOrderWithRespectTo(
name=model_name,
order_with_respect_to=order_with_respect_to,
),
dependencies=[
(app_label, model_name, order_with_respect_to, True),
(app_label, model_name, None, True),
],
)
related_dependencies = [
(app_label, model_name, name, True) for name in sorted(related_fields)
]
related_dependencies.append((app_label, model_name, None, True))
for index in indexes:
self.add_operation(
app_label,
operations.AddIndex(
model_name=model_name,
index=index,
),
dependencies=related_dependencies,
)
for constraint in constraints:
self.add_operation(
app_label,
operations.AddConstraint(
model_name=model_name,
constraint=constraint,
),
dependencies=related_dependencies,
)
if unique_together:
self.add_operation(
app_label,
operations.AlterUniqueTogether(
name=model_name,
unique_together=unique_together,
),
dependencies=related_dependencies,
)
# RemovedInDjango51Warning.
if index_together:
self.add_operation(
app_label,
operations.AlterIndexTogether(
name=model_name,
index_together=index_together,
),
dependencies=related_dependencies,
)
# Fix relationships if the model changed from a proxy model to a
# concrete model.
relations = self.to_state.relations
if (app_label, model_name) in self.old_proxy_keys:
for related_model_key, related_fields in relations[
app_label, model_name
].items():
related_model_state = self.to_state.models[related_model_key]
for related_field_name, related_field in related_fields.items():
self.add_operation(
related_model_state.app_label,
operations.AlterField(
model_name=related_model_state.name,
name=related_field_name,
field=related_field,
),
dependencies=[(app_label, model_name, None, True)],
)
def generate_created_proxies(self):
"""
Make CreateModel statements for proxy models. Use the same statements
as that way there's less code duplication, but for proxy models it's
safe to skip all the pointless field stuff and chuck out an operation.
"""
added = self.new_proxy_keys - self.old_proxy_keys
for app_label, model_name in sorted(added):
model_state = self.to_state.models[app_label, model_name]
assert model_state.options.get("proxy")
# Depend on the deletion of any possible non-proxy version of us
dependencies = [
(app_label, model_name, None, False),
]
# Depend on all bases
for base in model_state.bases:
if isinstance(base, str) and "." in base:
base_app_label, base_name = base.split(".", 1)
dependencies.append((base_app_label, base_name, None, True))
# Generate creation operation
self.add_operation(
app_label,
operations.CreateModel(
name=model_state.name,
fields=[],
options=model_state.options,
bases=model_state.bases,
managers=model_state.managers,
),
# Depend on the deletion of any possible non-proxy version of us
dependencies=dependencies,
)
def generate_deleted_models(self):
"""
Find all deleted models (managed and unmanaged) and make delete
operations for them as well as separate operations to delete any
foreign key or M2M relationships (these are optimized later, if
possible).
Also bring forward removal of any model options that refer to
collections of fields - the inverse of generate_created_models().
"""
new_keys = self.new_model_keys | self.new_unmanaged_keys
deleted_models = self.old_model_keys - new_keys
deleted_unmanaged_models = self.old_unmanaged_keys - new_keys
all_deleted_models = chain(
sorted(deleted_models), sorted(deleted_unmanaged_models)
)
for app_label, model_name in all_deleted_models:
model_state = self.from_state.models[app_label, model_name]
# Gather related fields
related_fields = {}
for field_name, field in model_state.fields.items():
if field.remote_field:
if field.remote_field.model:
related_fields[field_name] = field
if getattr(field.remote_field, "through", None):
related_fields[field_name] = field
# Generate option removal first
unique_together = model_state.options.pop("unique_together", None)
# RemovedInDjango51Warning.
index_together = model_state.options.pop("index_together", None)
if unique_together:
self.add_operation(
app_label,
operations.AlterUniqueTogether(
name=model_name,
unique_together=None,
),
)
# RemovedInDjango51Warning.
if index_together:
self.add_operation(
app_label,
operations.AlterIndexTogether(
name=model_name,
index_together=None,
),
)
# Then remove each related field
for name in sorted(related_fields):
self.add_operation(
app_label,
operations.RemoveField(
model_name=model_name,
name=name,
),
)
# Finally, remove the model.
# This depends on both the removal/alteration of all incoming fields
# and the removal of all its own related fields, and if it's
# a through model the field that references it.
dependencies = []
relations = self.from_state.relations
for (
related_object_app_label,
object_name,
), relation_related_fields in relations[app_label, model_name].items():
for field_name, field in relation_related_fields.items():
dependencies.append(
(related_object_app_label, object_name, field_name, False),
)
if not field.many_to_many:
dependencies.append(
(
related_object_app_label,
object_name,
field_name,
"alter",
),
)
for name in sorted(related_fields):
dependencies.append((app_label, model_name, name, False))
# We're referenced in another field's through=
through_user = self.through_users.get((app_label, model_state.name_lower))
if through_user:
dependencies.append(
(through_user[0], through_user[1], through_user[2], False)
)
# Finally, make the operation, deduping any dependencies
self.add_operation(
app_label,
operations.DeleteModel(
name=model_state.name,
),
dependencies=list(set(dependencies)),
)
def generate_deleted_proxies(self):
"""Make DeleteModel options for proxy models."""
deleted = self.old_proxy_keys - self.new_proxy_keys
for app_label, model_name in sorted(deleted):
model_state = self.from_state.models[app_label, model_name]
assert model_state.options.get("proxy")
self.add_operation(
app_label,
operations.DeleteModel(
name=model_state.name,
),
)
def create_renamed_fields(self):
"""Work out renamed fields."""
self.renamed_operations = []
old_field_keys = self.old_field_keys.copy()
for app_label, model_name, field_name in sorted(
self.new_field_keys - old_field_keys
):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
field = new_model_state.get_field(field_name)
# Scan to see if this is actually a rename!
field_dec = self.deep_deconstruct(field)
for rem_app_label, rem_model_name, rem_field_name in sorted(
old_field_keys - self.new_field_keys
):
if rem_app_label == app_label and rem_model_name == model_name:
old_field = old_model_state.get_field(rem_field_name)
old_field_dec = self.deep_deconstruct(old_field)
if (
field.remote_field
and field.remote_field.model
and "to" in old_field_dec[2]
):
old_rel_to = old_field_dec[2]["to"]
if old_rel_to in self.renamed_models_rel:
old_field_dec[2]["to"] = self.renamed_models_rel[old_rel_to]
old_field.set_attributes_from_name(rem_field_name)
old_db_column = old_field.get_attname_column()[1]
if old_field_dec == field_dec or (
# Was the field renamed and db_column equal to the
# old field's column added?
old_field_dec[0:2] == field_dec[0:2]
and dict(old_field_dec[2], db_column=old_db_column)
== field_dec[2]
):
if self.questioner.ask_rename(
model_name, rem_field_name, field_name, field
):
self.renamed_operations.append(
(
rem_app_label,
rem_model_name,
old_field.db_column,
rem_field_name,
app_label,
model_name,
field,
field_name,
)
)
old_field_keys.remove(
(rem_app_label, rem_model_name, rem_field_name)
)
old_field_keys.add((app_label, model_name, field_name))
self.renamed_fields[
app_label, model_name, field_name
] = rem_field_name
break
def generate_renamed_fields(self):
"""Generate RenameField operations."""
for (
rem_app_label,
rem_model_name,
rem_db_column,
rem_field_name,
app_label,
model_name,
field,
field_name,
) in self.renamed_operations:
# A db_column mismatch requires a prior noop AlterField for the
# subsequent RenameField to be a noop on attempts at preserving the
# old name.
if rem_db_column != field.db_column:
altered_field = field.clone()
altered_field.name = rem_field_name
self.add_operation(
app_label,
operations.AlterField(
model_name=model_name,
name=rem_field_name,
field=altered_field,
),
)
self.add_operation(
app_label,
operations.RenameField(
model_name=model_name,
old_name=rem_field_name,
new_name=field_name,
),
)
self.old_field_keys.remove((rem_app_label, rem_model_name, rem_field_name))
self.old_field_keys.add((app_label, model_name, field_name))
def generate_added_fields(self):
"""Make AddField operations."""
for app_label, model_name, field_name in sorted(
self.new_field_keys - self.old_field_keys
):
self._generate_added_field(app_label, model_name, field_name)
def _generate_added_field(self, app_label, model_name, field_name):
field = self.to_state.models[app_label, model_name].get_field(field_name)
# Adding a field always depends at least on its removal.
dependencies = [(app_label, model_name, field_name, False)]
# Fields that are foreignkeys/m2ms depend on stuff.
if field.remote_field and field.remote_field.model:
dependencies.extend(
self._get_dependencies_for_foreign_key(
app_label,
model_name,
field,
self.to_state,
)
)
# You can't just add NOT NULL fields with no default or fields
# which don't allow empty strings as default.
time_fields = (models.DateField, models.DateTimeField, models.TimeField)
preserve_default = (
field.null
or field.has_default()
or field.many_to_many
or (field.blank and field.empty_strings_allowed)
or (isinstance(field, time_fields) and field.auto_now)
)
if not preserve_default:
field = field.clone()
if isinstance(field, time_fields) and field.auto_now_add:
field.default = self.questioner.ask_auto_now_add_addition(
field_name, model_name
)
else:
field.default = self.questioner.ask_not_null_addition(
field_name, model_name
)
if (
field.unique
and field.default is not models.NOT_PROVIDED
and callable(field.default)
):
self.questioner.ask_unique_callable_default_addition(field_name, model_name)
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
),
dependencies=dependencies,
)
def generate_removed_fields(self):
"""Make RemoveField operations."""
for app_label, model_name, field_name in sorted(
self.old_field_keys - self.new_field_keys
):
self._generate_removed_field(app_label, model_name, field_name)
def _generate_removed_field(self, app_label, model_name, field_name):
self.add_operation(
app_label,
operations.RemoveField(
model_name=model_name,
name=field_name,
),
# We might need to depend on the removal of an
# order_with_respect_to or index/unique_together operation;
# this is safely ignored if there isn't one
dependencies=[
(app_label, model_name, field_name, "order_wrt_unset"),
(app_label, model_name, field_name, "foo_together_change"),
],
)
def generate_altered_fields(self):
"""
Make AlterField operations, or possibly RemovedField/AddField if alter
isn't possible.
"""
for app_label, model_name, field_name in sorted(
self.old_field_keys & self.new_field_keys
):
# Did the field change?
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_field_name = self.renamed_fields.get(
(app_label, model_name, field_name), field_name
)
old_field = self.from_state.models[app_label, old_model_name].get_field(
old_field_name
)
new_field = self.to_state.models[app_label, model_name].get_field(
field_name
)
dependencies = []
# Implement any model renames on relations; these are handled by RenameModel
# so we need to exclude them from the comparison
if hasattr(new_field, "remote_field") and getattr(
new_field.remote_field, "model", None
):
rename_key = resolve_relation(
new_field.remote_field.model, app_label, model_name
)
if rename_key in self.renamed_models:
new_field.remote_field.model = old_field.remote_field.model
# Handle ForeignKey which can only have a single to_field.
remote_field_name = getattr(new_field.remote_field, "field_name", None)
if remote_field_name:
to_field_rename_key = rename_key + (remote_field_name,)
if to_field_rename_key in self.renamed_fields:
# Repoint both model and field name because to_field
# inclusion in ForeignKey.deconstruct() is based on
# both.
new_field.remote_field.model = old_field.remote_field.model
new_field.remote_field.field_name = (
old_field.remote_field.field_name
)
# Handle ForeignObjects which can have multiple from_fields/to_fields.
from_fields = getattr(new_field, "from_fields", None)
if from_fields:
from_rename_key = (app_label, model_name)
new_field.from_fields = tuple(
[
self.renamed_fields.get(
from_rename_key + (from_field,), from_field
)
for from_field in from_fields
]
)
new_field.to_fields = tuple(
[
self.renamed_fields.get(rename_key + (to_field,), to_field)
for to_field in new_field.to_fields
]
)
dependencies.extend(
self._get_dependencies_for_foreign_key(
app_label,
model_name,
new_field,
self.to_state,
)
)
if hasattr(new_field, "remote_field") and getattr(
new_field.remote_field, "through", None
):
rename_key = resolve_relation(
new_field.remote_field.through, app_label, model_name
)
if rename_key in self.renamed_models:
new_field.remote_field.through = old_field.remote_field.through
old_field_dec = self.deep_deconstruct(old_field)
new_field_dec = self.deep_deconstruct(new_field)
# If the field was confirmed to be renamed it means that only
# db_column was allowed to change which generate_renamed_fields()
# already accounts for by adding an AlterField operation.
if old_field_dec != new_field_dec and old_field_name == field_name:
both_m2m = old_field.many_to_many and new_field.many_to_many
neither_m2m = not old_field.many_to_many and not new_field.many_to_many
if both_m2m or neither_m2m:
# Either both fields are m2m or neither is
preserve_default = True
if (
old_field.null
and not new_field.null
and not new_field.has_default()
and not new_field.many_to_many
):
field = new_field.clone()
new_default = self.questioner.ask_not_null_alteration(
field_name, model_name
)
if new_default is not models.NOT_PROVIDED:
field.default = new_default
preserve_default = False
else:
field = new_field
self.add_operation(
app_label,
operations.AlterField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
),
dependencies=dependencies,
)
else:
# We cannot alter between m2m and concrete fields
self._generate_removed_field(app_label, model_name, field_name)
self._generate_added_field(app_label, model_name, field_name)
def create_altered_indexes(self):
option_name = operations.AddIndex.option_name
self.renamed_index_together_values = defaultdict(list)
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_indexes = old_model_state.options[option_name]
new_indexes = new_model_state.options[option_name]
added_indexes = [idx for idx in new_indexes if idx not in old_indexes]
removed_indexes = [idx for idx in old_indexes if idx not in new_indexes]
renamed_indexes = []
# Find renamed indexes.
remove_from_added = []
remove_from_removed = []
for new_index in added_indexes:
new_index_dec = new_index.deconstruct()
new_index_name = new_index_dec[2].pop("name")
for old_index in removed_indexes:
old_index_dec = old_index.deconstruct()
old_index_name = old_index_dec[2].pop("name")
# Indexes are the same except for the names.
if (
new_index_dec == old_index_dec
and new_index_name != old_index_name
):
renamed_indexes.append((old_index_name, new_index_name, None))
remove_from_added.append(new_index)
remove_from_removed.append(old_index)
# Find index_together changed to indexes.
for (
old_value,
new_value,
index_together_app_label,
index_together_model_name,
dependencies,
) in self._get_altered_foo_together_operations(
operations.AlterIndexTogether.option_name
):
if (
app_label != index_together_app_label
or model_name != index_together_model_name
):
continue
removed_values = old_value.difference(new_value)
for removed_index_together in removed_values:
renamed_index_together_indexes = []
for new_index in added_indexes:
_, args, kwargs = new_index.deconstruct()
# Ensure only 'fields' are defined in the Index.
if (
not args
and new_index.fields == list(removed_index_together)
and set(kwargs) == {"name", "fields"}
):
renamed_index_together_indexes.append(new_index)
if len(renamed_index_together_indexes) == 1:
renamed_index = renamed_index_together_indexes[0]
remove_from_added.append(renamed_index)
renamed_indexes.append(
(None, renamed_index.name, removed_index_together)
)
self.renamed_index_together_values[
index_together_app_label, index_together_model_name
].append(removed_index_together)
# Remove renamed indexes from the lists of added and removed
# indexes.
added_indexes = [
idx for idx in added_indexes if idx not in remove_from_added
]
removed_indexes = [
idx for idx in removed_indexes if idx not in remove_from_removed
]
self.altered_indexes.update(
{
(app_label, model_name): {
"added_indexes": added_indexes,
"removed_indexes": removed_indexes,
"renamed_indexes": renamed_indexes,
}
}
)
def generate_added_indexes(self):
for (app_label, model_name), alt_indexes in self.altered_indexes.items():
for index in alt_indexes["added_indexes"]:
self.add_operation(
app_label,
operations.AddIndex(
model_name=model_name,
index=index,
),
)
def generate_removed_indexes(self):
for (app_label, model_name), alt_indexes in self.altered_indexes.items():
for index in alt_indexes["removed_indexes"]:
self.add_operation(
app_label,
operations.RemoveIndex(
model_name=model_name,
name=index.name,
),
)
def generate_renamed_indexes(self):
for (app_label, model_name), alt_indexes in self.altered_indexes.items():
for old_index_name, new_index_name, old_fields in alt_indexes[
"renamed_indexes"
]:
self.add_operation(
app_label,
operations.RenameIndex(
model_name=model_name,
new_name=new_index_name,
old_name=old_index_name,
old_fields=old_fields,
),
)
def create_altered_constraints(self):
option_name = operations.AddConstraint.option_name
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_constraints = old_model_state.options[option_name]
new_constraints = new_model_state.options[option_name]
add_constraints = [c for c in new_constraints if c not in old_constraints]
rem_constraints = [c for c in old_constraints if c not in new_constraints]
self.altered_constraints.update(
{
(app_label, model_name): {
"added_constraints": add_constraints,
"removed_constraints": rem_constraints,
}
}
)
def generate_added_constraints(self):
for (
app_label,
model_name,
), alt_constraints in self.altered_constraints.items():
for constraint in alt_constraints["added_constraints"]:
self.add_operation(
app_label,
operations.AddConstraint(
model_name=model_name,
constraint=constraint,
),
)
def generate_removed_constraints(self):
for (
app_label,
model_name,
), alt_constraints in self.altered_constraints.items():
for constraint in alt_constraints["removed_constraints"]:
self.add_operation(
app_label,
operations.RemoveConstraint(
model_name=model_name,
name=constraint.name,
),
)
@staticmethod
def _get_dependencies_for_foreign_key(app_label, model_name, field, project_state):
remote_field_model = None
if hasattr(field.remote_field, "model"):
remote_field_model = field.remote_field.model
else:
relations = project_state.relations[app_label, model_name]
for (remote_app_label, remote_model_name), fields in relations.items():
if any(
field == related_field.remote_field
for related_field in fields.values()
):
remote_field_model = f"{remote_app_label}.{remote_model_name}"
break
# Account for FKs to swappable models
swappable_setting = getattr(field, "swappable_setting", None)
if swappable_setting is not None:
dep_app_label = "__setting__"
dep_object_name = swappable_setting
else:
dep_app_label, dep_object_name = resolve_relation(
remote_field_model,
app_label,
model_name,
)
dependencies = [(dep_app_label, dep_object_name, None, True)]
if getattr(field.remote_field, "through", None):
through_app_label, through_object_name = resolve_relation(
field.remote_field.through,
app_label,
model_name,
)
dependencies.append((through_app_label, through_object_name, None, True))
return dependencies
def _get_altered_foo_together_operations(self, option_name):
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
# We run the old version through the field renames to account for those
old_value = old_model_state.options.get(option_name)
old_value = (
{
tuple(
self.renamed_fields.get((app_label, model_name, n), n)
for n in unique
)
for unique in old_value
}
if old_value
else set()
)
new_value = new_model_state.options.get(option_name)
new_value = set(new_value) if new_value else set()
if old_value != new_value:
dependencies = []
for foo_togethers in new_value:
for field_name in foo_togethers:
field = new_model_state.get_field(field_name)
if field.remote_field and field.remote_field.model:
dependencies.extend(
self._get_dependencies_for_foreign_key(
app_label,
model_name,
field,
self.to_state,
)
)
yield (
old_value,
new_value,
app_label,
model_name,
dependencies,
)
def _generate_removed_altered_foo_together(self, operation):
for (
old_value,
new_value,
app_label,
model_name,
dependencies,
) in self._get_altered_foo_together_operations(operation.option_name):
if operation == operations.AlterIndexTogether:
old_value = {
value
for value in old_value
if value
not in self.renamed_index_together_values[app_label, model_name]
}
removal_value = new_value.intersection(old_value)
if removal_value or old_value:
self.add_operation(
app_label,
operation(
name=model_name, **{operation.option_name: removal_value}
),
dependencies=dependencies,
)
def generate_removed_altered_unique_together(self):
self._generate_removed_altered_foo_together(operations.AlterUniqueTogether)
# RemovedInDjango51Warning.
def generate_removed_altered_index_together(self):
self._generate_removed_altered_foo_together(operations.AlterIndexTogether)
def _generate_altered_foo_together(self, operation):
for (
old_value,
new_value,
app_label,
model_name,
dependencies,
) in self._get_altered_foo_together_operations(operation.option_name):
removal_value = new_value.intersection(old_value)
if new_value != removal_value:
self.add_operation(
app_label,
operation(name=model_name, **{operation.option_name: new_value}),
dependencies=dependencies,
)
def generate_altered_unique_together(self):
self._generate_altered_foo_together(operations.AlterUniqueTogether)
# RemovedInDjango51Warning.
def generate_altered_index_together(self):
self._generate_altered_foo_together(operations.AlterIndexTogether)
def generate_altered_db_table(self):
models_to_check = self.kept_model_keys.union(
self.kept_proxy_keys, self.kept_unmanaged_keys
)
for app_label, model_name in sorted(models_to_check):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_db_table_name = old_model_state.options.get("db_table")
new_db_table_name = new_model_state.options.get("db_table")
if old_db_table_name != new_db_table_name:
self.add_operation(
app_label,
operations.AlterModelTable(
name=model_name,
table=new_db_table_name,
),
)
def generate_altered_db_table_comment(self):
models_to_check = self.kept_model_keys.union(
self.kept_proxy_keys, self.kept_unmanaged_keys
)
for app_label, model_name in sorted(models_to_check):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_db_table_comment = old_model_state.options.get("db_table_comment")
new_db_table_comment = new_model_state.options.get("db_table_comment")
if old_db_table_comment != new_db_table_comment:
self.add_operation(
app_label,
operations.AlterModelTableComment(
name=model_name,
table_comment=new_db_table_comment,
),
)
def generate_altered_options(self):
"""
Work out if any non-schema-affecting options have changed and make an
operation to represent them in state changes (in case Python code in
migrations needs them).
"""
models_to_check = self.kept_model_keys.union(
self.kept_proxy_keys,
self.kept_unmanaged_keys,
# unmanaged converted to managed
self.old_unmanaged_keys & self.new_model_keys,
# managed converted to unmanaged
self.old_model_keys & self.new_unmanaged_keys,
)
for app_label, model_name in sorted(models_to_check):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_options = {
key: value
for key, value in old_model_state.options.items()
if key in AlterModelOptions.ALTER_OPTION_KEYS
}
new_options = {
key: value
for key, value in new_model_state.options.items()
if key in AlterModelOptions.ALTER_OPTION_KEYS
}
if old_options != new_options:
self.add_operation(
app_label,
operations.AlterModelOptions(
name=model_name,
options=new_options,
),
)
def generate_altered_order_with_respect_to(self):
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
if old_model_state.options.get(
"order_with_respect_to"
) != new_model_state.options.get("order_with_respect_to"):
# Make sure it comes second if we're adding
# (removal dependency is part of RemoveField)
dependencies = []
if new_model_state.options.get("order_with_respect_to"):
dependencies.append(
(
app_label,
model_name,
new_model_state.options["order_with_respect_to"],
True,
)
)
# Actually generate the operation
self.add_operation(
app_label,
operations.AlterOrderWithRespectTo(
name=model_name,
order_with_respect_to=new_model_state.options.get(
"order_with_respect_to"
),
),
dependencies=dependencies,
)
def generate_altered_managers(self):
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get(
(app_label, model_name), model_name
)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
if old_model_state.managers != new_model_state.managers:
self.add_operation(
app_label,
operations.AlterModelManagers(
name=model_name,
managers=new_model_state.managers,
),
)
def arrange_for_graph(self, changes, graph, migration_name=None):
"""
Take a result from changes() and a MigrationGraph, and fix the names
and dependencies of the changes so they extend the graph from the leaf
nodes for each app.
"""
leaves = graph.leaf_nodes()
name_map = {}
for app_label, migrations in list(changes.items()):
if not migrations:
continue
# Find the app label's current leaf node
app_leaf = None
for leaf in leaves:
if leaf[0] == app_label:
app_leaf = leaf
break
# Do they want an initial migration for this app?
if app_leaf is None and not self.questioner.ask_initial(app_label):
# They don't.
for migration in migrations:
name_map[(app_label, migration.name)] = (app_label, "__first__")
del changes[app_label]
continue
# Work out the next number in the sequence
if app_leaf is None:
next_number = 1
else:
next_number = (self.parse_number(app_leaf[1]) or 0) + 1
# Name each migration
for i, migration in enumerate(migrations):
if i == 0 and app_leaf:
migration.dependencies.append(app_leaf)
new_name_parts = ["%04i" % next_number]
if migration_name:
new_name_parts.append(migration_name)
elif i == 0 and not app_leaf:
new_name_parts.append("initial")
else:
new_name_parts.append(migration.suggest_name()[:100])
new_name = "_".join(new_name_parts)
name_map[(app_label, migration.name)] = (app_label, new_name)
next_number += 1
migration.name = new_name
# Now fix dependencies
for migrations in changes.values():
for migration in migrations:
migration.dependencies = [
name_map.get(d, d) for d in migration.dependencies
]
return changes
def _trim_to_apps(self, changes, app_labels):
"""
Take changes from arrange_for_graph() and set of app labels, and return
a modified set of changes which trims out as many migrations that are
not in app_labels as possible. Note that some other migrations may
still be present as they may be required dependencies.
"""
# Gather other app dependencies in a first pass
app_dependencies = {}
for app_label, migrations in changes.items():
for migration in migrations:
for dep_app_label, name in migration.dependencies:
app_dependencies.setdefault(app_label, set()).add(dep_app_label)
required_apps = set(app_labels)
# Keep resolving till there's no change
old_required_apps = None
while old_required_apps != required_apps:
old_required_apps = set(required_apps)
required_apps.update(
*[app_dependencies.get(app_label, ()) for app_label in required_apps]
)
# Remove all migrations that aren't needed
for app_label in list(changes):
if app_label not in required_apps:
del changes[app_label]
return changes
@classmethod
def parse_number(cls, name):
"""
Given a migration name, try to extract a number from the beginning of
it. For a squashed migration such as '0001_squashed_0004…', return the
second number. If no number is found, return None.
"""
if squashed_match := re.search(r".*_squashed_(\d+)", name):
return int(squashed_match[1])
match = re.match(r"^\d+", name)
if match:
return int(match[0])
return None
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/autodetector.py
|
Python
|
mit
| 78,977 |
from django.db import DatabaseError
class AmbiguityError(Exception):
"""More than one migration matches a name prefix."""
pass
class BadMigrationError(Exception):
"""There's a bad migration (unreadable/bad format/etc.)."""
pass
class CircularDependencyError(Exception):
"""There's an impossible-to-resolve circular dependency."""
pass
class InconsistentMigrationHistory(Exception):
"""An applied migration has some of its dependencies not applied."""
pass
class InvalidBasesError(ValueError):
"""A model's base classes can't be resolved."""
pass
class IrreversibleError(RuntimeError):
"""An irreversible migration is about to be reversed."""
pass
class NodeNotFoundError(LookupError):
"""An attempt on a node is made that is not available in the graph."""
def __init__(self, message, node, origin=None):
self.message = message
self.origin = origin
self.node = node
def __str__(self):
return self.message
def __repr__(self):
return "NodeNotFoundError(%r)" % (self.node,)
class MigrationSchemaMissing(DatabaseError):
pass
class InvalidMigrationPlan(ValueError):
pass
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/exceptions.py
|
Python
|
mit
| 1,204 |
from django.apps.registry import apps as global_apps
from django.db import migrations, router
from .exceptions import InvalidMigrationPlan
from .loader import MigrationLoader
from .recorder import MigrationRecorder
from .state import ProjectState
class MigrationExecutor:
"""
End-to-end migration execution - load migrations and run them up or down
to a specified set of targets.
"""
def __init__(self, connection, progress_callback=None):
self.connection = connection
self.loader = MigrationLoader(self.connection)
self.recorder = MigrationRecorder(self.connection)
self.progress_callback = progress_callback
def migration_plan(self, targets, clean_start=False):
"""
Given a set of targets, return a list of (Migration instance, backwards?).
"""
plan = []
if clean_start:
applied = {}
else:
applied = dict(self.loader.applied_migrations)
for target in targets:
# If the target is (app_label, None), that means unmigrate everything
if target[1] is None:
for root in self.loader.graph.root_nodes():
if root[0] == target[0]:
for migration in self.loader.graph.backwards_plan(root):
if migration in applied:
plan.append((self.loader.graph.nodes[migration], True))
applied.pop(migration)
# If the migration is already applied, do backwards mode,
# otherwise do forwards mode.
elif target in applied:
# If the target is missing, it's likely a replaced migration.
# Reload the graph without replacements.
if (
self.loader.replace_migrations
and target not in self.loader.graph.node_map
):
self.loader.replace_migrations = False
self.loader.build_graph()
return self.migration_plan(targets, clean_start=clean_start)
# Don't migrate backwards all the way to the target node (that
# may roll back dependencies in other apps that don't need to
# be rolled back); instead roll back through target's immediate
# child(ren) in the same app, and no further.
next_in_app = sorted(
n
for n in self.loader.graph.node_map[target].children
if n[0] == target[0]
)
for node in next_in_app:
for migration in self.loader.graph.backwards_plan(node):
if migration in applied:
plan.append((self.loader.graph.nodes[migration], True))
applied.pop(migration)
else:
for migration in self.loader.graph.forwards_plan(target):
if migration not in applied:
plan.append((self.loader.graph.nodes[migration], False))
applied[migration] = self.loader.graph.nodes[migration]
return plan
def _create_project_state(self, with_applied_migrations=False):
"""
Create a project state including all the applications without
migrations and applied migrations if with_applied_migrations=True.
"""
state = ProjectState(real_apps=self.loader.unmigrated_apps)
if with_applied_migrations:
# Create the forwards plan Django would follow on an empty database
full_plan = self.migration_plan(
self.loader.graph.leaf_nodes(), clean_start=True
)
applied_migrations = {
self.loader.graph.nodes[key]
for key in self.loader.applied_migrations
if key in self.loader.graph.nodes
}
for migration, _ in full_plan:
if migration in applied_migrations:
migration.mutate_state(state, preserve=False)
return state
def migrate(self, targets, plan=None, state=None, fake=False, fake_initial=False):
"""
Migrate the database up to the given targets.
Django first needs to create all project states before a migration is
(un)applied and in a second step run all the database operations.
"""
# The django_migrations table must be present to record applied
# migrations, but don't create it if there are no migrations to apply.
if plan == []:
if not self.recorder.has_table():
return self._create_project_state(with_applied_migrations=False)
else:
self.recorder.ensure_schema()
if plan is None:
plan = self.migration_plan(targets)
# Create the forwards plan Django would follow on an empty database
full_plan = self.migration_plan(
self.loader.graph.leaf_nodes(), clean_start=True
)
all_forwards = all(not backwards for mig, backwards in plan)
all_backwards = all(backwards for mig, backwards in plan)
if not plan:
if state is None:
# The resulting state should include applied migrations.
state = self._create_project_state(with_applied_migrations=True)
elif all_forwards == all_backwards:
# This should only happen if there's a mixed plan
raise InvalidMigrationPlan(
"Migration plans with both forwards and backwards migrations "
"are not supported. Please split your migration process into "
"separate plans of only forwards OR backwards migrations.",
plan,
)
elif all_forwards:
if state is None:
# The resulting state should still include applied migrations.
state = self._create_project_state(with_applied_migrations=True)
state = self._migrate_all_forwards(
state, plan, full_plan, fake=fake, fake_initial=fake_initial
)
else:
# No need to check for `elif all_backwards` here, as that condition
# would always evaluate to true.
state = self._migrate_all_backwards(plan, full_plan, fake=fake)
self.check_replacements()
return state
def _migrate_all_forwards(self, state, plan, full_plan, fake, fake_initial):
"""
Take a list of 2-tuples of the form (migration instance, False) and
apply them in the order they occur in the full_plan.
"""
migrations_to_run = {m[0] for m in plan}
for migration, _ in full_plan:
if not migrations_to_run:
# We remove every migration that we applied from these sets so
# that we can bail out once the last migration has been applied
# and don't always run until the very end of the migration
# process.
break
if migration in migrations_to_run:
if "apps" not in state.__dict__:
if self.progress_callback:
self.progress_callback("render_start")
state.apps # Render all -- performance critical
if self.progress_callback:
self.progress_callback("render_success")
state = self.apply_migration(
state, migration, fake=fake, fake_initial=fake_initial
)
migrations_to_run.remove(migration)
return state
def _migrate_all_backwards(self, plan, full_plan, fake):
"""
Take a list of 2-tuples of the form (migration instance, True) and
unapply them in reverse order they occur in the full_plan.
Since unapplying a migration requires the project state prior to that
migration, Django will compute the migration states before each of them
in a first run over the plan and then unapply them in a second run over
the plan.
"""
migrations_to_run = {m[0] for m in plan}
# Holds all migration states prior to the migrations being unapplied
states = {}
state = self._create_project_state()
applied_migrations = {
self.loader.graph.nodes[key]
for key in self.loader.applied_migrations
if key in self.loader.graph.nodes
}
if self.progress_callback:
self.progress_callback("render_start")
for migration, _ in full_plan:
if not migrations_to_run:
# We remove every migration that we applied from this set so
# that we can bail out once the last migration has been applied
# and don't always run until the very end of the migration
# process.
break
if migration in migrations_to_run:
if "apps" not in state.__dict__:
state.apps # Render all -- performance critical
# The state before this migration
states[migration] = state
# The old state keeps as-is, we continue with the new state
state = migration.mutate_state(state, preserve=True)
migrations_to_run.remove(migration)
elif migration in applied_migrations:
# Only mutate the state if the migration is actually applied
# to make sure the resulting state doesn't include changes
# from unrelated migrations.
migration.mutate_state(state, preserve=False)
if self.progress_callback:
self.progress_callback("render_success")
for migration, _ in plan:
self.unapply_migration(states[migration], migration, fake=fake)
applied_migrations.remove(migration)
# Generate the post migration state by starting from the state before
# the last migration is unapplied and mutating it to include all the
# remaining applied migrations.
last_unapplied_migration = plan[-1][0]
state = states[last_unapplied_migration]
for index, (migration, _) in enumerate(full_plan):
if migration == last_unapplied_migration:
for migration, _ in full_plan[index:]:
if migration in applied_migrations:
migration.mutate_state(state, preserve=False)
break
return state
def apply_migration(self, state, migration, fake=False, fake_initial=False):
"""Run a migration forwards."""
migration_recorded = False
if self.progress_callback:
self.progress_callback("apply_start", migration, fake)
if not fake:
if fake_initial:
# Test to see if this is an already-applied initial migration
applied, state = self.detect_soft_applied(state, migration)
if applied:
fake = True
if not fake:
# Alright, do it normally
with self.connection.schema_editor(
atomic=migration.atomic
) as schema_editor:
state = migration.apply(state, schema_editor)
if not schema_editor.deferred_sql:
self.record_migration(migration)
migration_recorded = True
if not migration_recorded:
self.record_migration(migration)
# Report progress
if self.progress_callback:
self.progress_callback("apply_success", migration, fake)
return state
def record_migration(self, migration):
# For replacement migrations, record individual statuses
if migration.replaces:
for app_label, name in migration.replaces:
self.recorder.record_applied(app_label, name)
else:
self.recorder.record_applied(migration.app_label, migration.name)
def unapply_migration(self, state, migration, fake=False):
"""Run a migration backwards."""
if self.progress_callback:
self.progress_callback("unapply_start", migration, fake)
if not fake:
with self.connection.schema_editor(
atomic=migration.atomic
) as schema_editor:
state = migration.unapply(state, schema_editor)
# For replacement migrations, also record individual statuses.
if migration.replaces:
for app_label, name in migration.replaces:
self.recorder.record_unapplied(app_label, name)
self.recorder.record_unapplied(migration.app_label, migration.name)
# Report progress
if self.progress_callback:
self.progress_callback("unapply_success", migration, fake)
return state
def check_replacements(self):
"""
Mark replacement migrations applied if their replaced set all are.
Do this unconditionally on every migrate, rather than just when
migrations are applied or unapplied, to correctly handle the case
when a new squash migration is pushed to a deployment that already had
all its replaced migrations applied. In this case no new migration will
be applied, but the applied state of the squashed migration must be
maintained.
"""
applied = self.recorder.applied_migrations()
for key, migration in self.loader.replacements.items():
all_applied = all(m in applied for m in migration.replaces)
if all_applied and key not in applied:
self.recorder.record_applied(*key)
def detect_soft_applied(self, project_state, migration):
"""
Test whether a migration has been implicitly applied - that the
tables or columns it would create exist. This is intended only for use
on initial migrations (as it only looks for CreateModel and AddField).
"""
def should_skip_detecting_model(migration, model):
"""
No need to detect tables for proxy models, unmanaged models, or
models that can't be migrated on the current database.
"""
return (
model._meta.proxy
or not model._meta.managed
or not router.allow_migrate(
self.connection.alias,
migration.app_label,
model_name=model._meta.model_name,
)
)
if migration.initial is None:
# Bail if the migration isn't the first one in its app
if any(app == migration.app_label for app, name in migration.dependencies):
return False, project_state
elif migration.initial is False:
# Bail if it's NOT an initial migration
return False, project_state
if project_state is None:
after_state = self.loader.project_state(
(migration.app_label, migration.name), at_end=True
)
else:
after_state = migration.mutate_state(project_state)
apps = after_state.apps
found_create_model_migration = False
found_add_field_migration = False
fold_identifier_case = self.connection.features.ignores_table_name_case
with self.connection.cursor() as cursor:
existing_table_names = set(
self.connection.introspection.table_names(cursor)
)
if fold_identifier_case:
existing_table_names = {
name.casefold() for name in existing_table_names
}
# Make sure all create model and add field operations are done
for operation in migration.operations:
if isinstance(operation, migrations.CreateModel):
model = apps.get_model(migration.app_label, operation.name)
if model._meta.swapped:
# We have to fetch the model to test with from the
# main app cache, as it's not a direct dependency.
model = global_apps.get_model(model._meta.swapped)
if should_skip_detecting_model(migration, model):
continue
db_table = model._meta.db_table
if fold_identifier_case:
db_table = db_table.casefold()
if db_table not in existing_table_names:
return False, project_state
found_create_model_migration = True
elif isinstance(operation, migrations.AddField):
model = apps.get_model(migration.app_label, operation.model_name)
if model._meta.swapped:
# We have to fetch the model to test with from the
# main app cache, as it's not a direct dependency.
model = global_apps.get_model(model._meta.swapped)
if should_skip_detecting_model(migration, model):
continue
table = model._meta.db_table
field = model._meta.get_field(operation.name)
# Handle implicit many-to-many tables created by AddField.
if field.many_to_many:
through_db_table = field.remote_field.through._meta.db_table
if fold_identifier_case:
through_db_table = through_db_table.casefold()
if through_db_table not in existing_table_names:
return False, project_state
else:
found_add_field_migration = True
continue
with self.connection.cursor() as cursor:
columns = self.connection.introspection.get_table_description(
cursor, table
)
for column in columns:
field_column = field.column
column_name = column.name
if fold_identifier_case:
column_name = column_name.casefold()
field_column = field_column.casefold()
if column_name == field_column:
found_add_field_migration = True
break
else:
return False, project_state
# If we get this far and we found at least one CreateModel or AddField
# migration, the migration is considered implicitly applied.
return (found_create_model_migration or found_add_field_migration), after_state
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/executor.py
|
Python
|
mit
| 18,923 |
from functools import total_ordering
from django.db.migrations.state import ProjectState
from .exceptions import CircularDependencyError, NodeNotFoundError
@total_ordering
class Node:
"""
A single node in the migration graph. Contains direct links to adjacent
nodes in either direction.
"""
def __init__(self, key):
self.key = key
self.children = set()
self.parents = set()
def __eq__(self, other):
return self.key == other
def __lt__(self, other):
return self.key < other
def __hash__(self):
return hash(self.key)
def __getitem__(self, item):
return self.key[item]
def __str__(self):
return str(self.key)
def __repr__(self):
return "<%s: (%r, %r)>" % (self.__class__.__name__, self.key[0], self.key[1])
def add_child(self, child):
self.children.add(child)
def add_parent(self, parent):
self.parents.add(parent)
class DummyNode(Node):
"""
A node that doesn't correspond to a migration file on disk.
(A squashed migration that was removed, for example.)
After the migration graph is processed, all dummy nodes should be removed.
If there are any left, a nonexistent dependency error is raised.
"""
def __init__(self, key, origin, error_message):
super().__init__(key)
self.origin = origin
self.error_message = error_message
def raise_error(self):
raise NodeNotFoundError(self.error_message, self.key, origin=self.origin)
class MigrationGraph:
"""
Represent the digraph of all migrations in a project.
Each migration is a node, and each dependency is an edge. There are
no implicit dependencies between numbered migrations - the numbering is
merely a convention to aid file listing. Every new numbered migration
has a declared dependency to the previous number, meaning that VCS
branch merges can be detected and resolved.
Migrations files can be marked as replacing another set of migrations -
this is to support the "squash" feature. The graph handler isn't responsible
for these; instead, the code to load them in here should examine the
migration files and if the replaced migrations are all either unapplied
or not present, it should ignore the replaced ones, load in just the
replacing migration, and repoint any dependencies that pointed to the
replaced migrations to point to the replacing one.
A node should be a tuple: (app_path, migration_name). The tree special-cases
things within an app - namely, root nodes and leaf nodes ignore dependencies
to other apps.
"""
def __init__(self):
self.node_map = {}
self.nodes = {}
def add_node(self, key, migration):
assert key not in self.node_map
node = Node(key)
self.node_map[key] = node
self.nodes[key] = migration
def add_dummy_node(self, key, origin, error_message):
node = DummyNode(key, origin, error_message)
self.node_map[key] = node
self.nodes[key] = None
def add_dependency(self, migration, child, parent, skip_validation=False):
"""
This may create dummy nodes if they don't yet exist. If
`skip_validation=True`, validate_consistency() should be called
afterward.
"""
if child not in self.nodes:
error_message = (
"Migration %s dependencies reference nonexistent"
" child node %r" % (migration, child)
)
self.add_dummy_node(child, migration, error_message)
if parent not in self.nodes:
error_message = (
"Migration %s dependencies reference nonexistent"
" parent node %r" % (migration, parent)
)
self.add_dummy_node(parent, migration, error_message)
self.node_map[child].add_parent(self.node_map[parent])
self.node_map[parent].add_child(self.node_map[child])
if not skip_validation:
self.validate_consistency()
def remove_replaced_nodes(self, replacement, replaced):
"""
Remove each of the `replaced` nodes (when they exist). Any
dependencies that were referencing them are changed to reference the
`replacement` node instead.
"""
# Cast list of replaced keys to set to speed up lookup later.
replaced = set(replaced)
try:
replacement_node = self.node_map[replacement]
except KeyError as err:
raise NodeNotFoundError(
"Unable to find replacement node %r. It was either never added"
" to the migration graph, or has been removed." % (replacement,),
replacement,
) from err
for replaced_key in replaced:
self.nodes.pop(replaced_key, None)
replaced_node = self.node_map.pop(replaced_key, None)
if replaced_node:
for child in replaced_node.children:
child.parents.remove(replaced_node)
# We don't want to create dependencies between the replaced
# node and the replacement node as this would lead to
# self-referencing on the replacement node at a later iteration.
if child.key not in replaced:
replacement_node.add_child(child)
child.add_parent(replacement_node)
for parent in replaced_node.parents:
parent.children.remove(replaced_node)
# Again, to avoid self-referencing.
if parent.key not in replaced:
replacement_node.add_parent(parent)
parent.add_child(replacement_node)
def remove_replacement_node(self, replacement, replaced):
"""
The inverse operation to `remove_replaced_nodes`. Almost. Remove the
replacement node `replacement` and remap its child nodes to `replaced`
- the list of nodes it would have replaced. Don't remap its parent
nodes as they are expected to be correct already.
"""
self.nodes.pop(replacement, None)
try:
replacement_node = self.node_map.pop(replacement)
except KeyError as err:
raise NodeNotFoundError(
"Unable to remove replacement node %r. It was either never added"
" to the migration graph, or has been removed already."
% (replacement,),
replacement,
) from err
replaced_nodes = set()
replaced_nodes_parents = set()
for key in replaced:
replaced_node = self.node_map.get(key)
if replaced_node:
replaced_nodes.add(replaced_node)
replaced_nodes_parents |= replaced_node.parents
# We're only interested in the latest replaced node, so filter out
# replaced nodes that are parents of other replaced nodes.
replaced_nodes -= replaced_nodes_parents
for child in replacement_node.children:
child.parents.remove(replacement_node)
for replaced_node in replaced_nodes:
replaced_node.add_child(child)
child.add_parent(replaced_node)
for parent in replacement_node.parents:
parent.children.remove(replacement_node)
# NOTE: There is no need to remap parent dependencies as we can
# assume the replaced nodes already have the correct ancestry.
def validate_consistency(self):
"""Ensure there are no dummy nodes remaining in the graph."""
[n.raise_error() for n in self.node_map.values() if isinstance(n, DummyNode)]
def forwards_plan(self, target):
"""
Given a node, return a list of which previous nodes (dependencies) must
be applied, ending with the node itself. This is the list you would
follow if applying the migrations to a database.
"""
if target not in self.nodes:
raise NodeNotFoundError("Node %r not a valid node" % (target,), target)
return self.iterative_dfs(self.node_map[target])
def backwards_plan(self, target):
"""
Given a node, return a list of which dependent nodes (dependencies)
must be unapplied, ending with the node itself. This is the list you
would follow if removing the migrations from a database.
"""
if target not in self.nodes:
raise NodeNotFoundError("Node %r not a valid node" % (target,), target)
return self.iterative_dfs(self.node_map[target], forwards=False)
def iterative_dfs(self, start, forwards=True):
"""Iterative depth-first search for finding dependencies."""
visited = []
visited_set = set()
stack = [(start, False)]
while stack:
node, processed = stack.pop()
if node in visited_set:
pass
elif processed:
visited_set.add(node)
visited.append(node.key)
else:
stack.append((node, True))
stack += [
(n, False)
for n in sorted(node.parents if forwards else node.children)
]
return visited
def root_nodes(self, app=None):
"""
Return all root nodes - that is, nodes with no dependencies inside
their app. These are the starting point for an app.
"""
roots = set()
for node in self.nodes:
if all(key[0] != node[0] for key in self.node_map[node].parents) and (
not app or app == node[0]
):
roots.add(node)
return sorted(roots)
def leaf_nodes(self, app=None):
"""
Return all leaf nodes - that is, nodes with no dependents in their app.
These are the "most current" version of an app's schema.
Having more than one per app is technically an error, but one that
gets handled further up, in the interactive command - it's usually the
result of a VCS merge and needs some user input.
"""
leaves = set()
for node in self.nodes:
if all(key[0] != node[0] for key in self.node_map[node].children) and (
not app or app == node[0]
):
leaves.add(node)
return sorted(leaves)
def ensure_not_cyclic(self):
# Algo from GvR:
# https://neopythonic.blogspot.com/2009/01/detecting-cycles-in-directed-graph.html
todo = set(self.nodes)
while todo:
node = todo.pop()
stack = [node]
while stack:
top = stack[-1]
for child in self.node_map[top].children:
# Use child.key instead of child to speed up the frequent
# hashing.
node = child.key
if node in stack:
cycle = stack[stack.index(node) :]
raise CircularDependencyError(
", ".join("%s.%s" % n for n in cycle)
)
if node in todo:
stack.append(node)
todo.remove(node)
break
else:
node = stack.pop()
def __str__(self):
return "Graph: %s nodes, %s edges" % self._nodes_and_edges()
def __repr__(self):
nodes, edges = self._nodes_and_edges()
return "<%s: nodes=%s, edges=%s>" % (self.__class__.__name__, nodes, edges)
def _nodes_and_edges(self):
return len(self.nodes), sum(
len(node.parents) for node in self.node_map.values()
)
def _generate_plan(self, nodes, at_end):
plan = []
for node in nodes:
for migration in self.forwards_plan(node):
if migration not in plan and (at_end or migration not in nodes):
plan.append(migration)
return plan
def make_state(self, nodes=None, at_end=True, real_apps=None):
"""
Given a migration node or nodes, return a complete ProjectState for it.
If at_end is False, return the state before the migration has run.
If nodes is not provided, return the overall most current project state.
"""
if nodes is None:
nodes = list(self.leaf_nodes())
if not nodes:
return ProjectState()
if not isinstance(nodes[0], tuple):
nodes = [nodes]
plan = self._generate_plan(nodes, at_end)
project_state = ProjectState(real_apps=real_apps)
for node in plan:
project_state = self.nodes[node].mutate_state(project_state, preserve=False)
return project_state
def __contains__(self, node):
return node in self.nodes
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/graph.py
|
Python
|
mit
| 13,055 |
import pkgutil
import sys
from importlib import import_module, reload
from django.apps import apps
from django.conf import settings
from django.db.migrations.graph import MigrationGraph
from django.db.migrations.recorder import MigrationRecorder
from .exceptions import (
AmbiguityError,
BadMigrationError,
InconsistentMigrationHistory,
NodeNotFoundError,
)
MIGRATIONS_MODULE_NAME = "migrations"
class MigrationLoader:
"""
Load migration files from disk and their status from the database.
Migration files are expected to live in the "migrations" directory of
an app. Their names are entirely unimportant from a code perspective,
but will probably follow the 1234_name.py convention.
On initialization, this class will scan those directories, and open and
read the Python files, looking for a class called Migration, which should
inherit from django.db.migrations.Migration. See
django.db.migrations.migration for what that looks like.
Some migrations will be marked as "replacing" another set of migrations.
These are loaded into a separate set of migrations away from the main ones.
If all the migrations they replace are either unapplied or missing from
disk, then they are injected into the main set, replacing the named migrations.
Any dependency pointers to the replaced migrations are re-pointed to the
new migration.
This does mean that this class MUST also talk to the database as well as
to disk, but this is probably fine. We're already not just operating
in memory.
"""
def __init__(
self,
connection,
load=True,
ignore_no_migrations=False,
replace_migrations=True,
):
self.connection = connection
self.disk_migrations = None
self.applied_migrations = None
self.ignore_no_migrations = ignore_no_migrations
self.replace_migrations = replace_migrations
if load:
self.build_graph()
@classmethod
def migrations_module(cls, app_label):
"""
Return the path to the migrations module for the specified app_label
and a boolean indicating if the module is specified in
settings.MIGRATION_MODULE.
"""
if app_label in settings.MIGRATION_MODULES:
return settings.MIGRATION_MODULES[app_label], True
else:
app_package_name = apps.get_app_config(app_label).name
return "%s.%s" % (app_package_name, MIGRATIONS_MODULE_NAME), False
def load_disk(self):
"""Load the migrations from all INSTALLED_APPS from disk."""
self.disk_migrations = {}
self.unmigrated_apps = set()
self.migrated_apps = set()
for app_config in apps.get_app_configs():
# Get the migrations module directory
module_name, explicit = self.migrations_module(app_config.label)
if module_name is None:
self.unmigrated_apps.add(app_config.label)
continue
was_loaded = module_name in sys.modules
try:
module = import_module(module_name)
except ModuleNotFoundError as e:
if (explicit and self.ignore_no_migrations) or (
not explicit and MIGRATIONS_MODULE_NAME in e.name.split(".")
):
self.unmigrated_apps.add(app_config.label)
continue
raise
else:
# Module is not a package (e.g. migrations.py).
if not hasattr(module, "__path__"):
self.unmigrated_apps.add(app_config.label)
continue
# Empty directories are namespaces. Namespace packages have no
# __file__ and don't use a list for __path__. See
# https://docs.python.org/3/reference/import.html#namespace-packages
if getattr(module, "__file__", None) is None and not isinstance(
module.__path__, list
):
self.unmigrated_apps.add(app_config.label)
continue
# Force a reload if it's already loaded (tests need this)
if was_loaded:
reload(module)
self.migrated_apps.add(app_config.label)
migration_names = {
name
for _, name, is_pkg in pkgutil.iter_modules(module.__path__)
if not is_pkg and name[0] not in "_~"
}
# Load migrations
for migration_name in migration_names:
migration_path = "%s.%s" % (module_name, migration_name)
try:
migration_module = import_module(migration_path)
except ImportError as e:
if "bad magic number" in str(e):
raise ImportError(
"Couldn't import %r as it appears to be a stale "
".pyc file." % migration_path
) from e
else:
raise
if not hasattr(migration_module, "Migration"):
raise BadMigrationError(
"Migration %s in app %s has no Migration class"
% (migration_name, app_config.label)
)
self.disk_migrations[
app_config.label, migration_name
] = migration_module.Migration(
migration_name,
app_config.label,
)
def get_migration(self, app_label, name_prefix):
"""Return the named migration or raise NodeNotFoundError."""
return self.graph.nodes[app_label, name_prefix]
def get_migration_by_prefix(self, app_label, name_prefix):
"""
Return the migration(s) which match the given app label and name_prefix.
"""
# Do the search
results = []
for migration_app_label, migration_name in self.disk_migrations:
if migration_app_label == app_label and migration_name.startswith(
name_prefix
):
results.append((migration_app_label, migration_name))
if len(results) > 1:
raise AmbiguityError(
"There is more than one migration for '%s' with the prefix '%s'"
% (app_label, name_prefix)
)
elif not results:
raise KeyError(
f"There is no migration for '{app_label}' with the prefix "
f"'{name_prefix}'"
)
else:
return self.disk_migrations[results[0]]
def check_key(self, key, current_app):
if (key[1] != "__first__" and key[1] != "__latest__") or key in self.graph:
return key
# Special-case __first__, which means "the first migration" for
# migrated apps, and is ignored for unmigrated apps. It allows
# makemigrations to declare dependencies on apps before they even have
# migrations.
if key[0] == current_app:
# Ignore __first__ references to the same app (#22325)
return
if key[0] in self.unmigrated_apps:
# This app isn't migrated, but something depends on it.
# The models will get auto-added into the state, though
# so we're fine.
return
if key[0] in self.migrated_apps:
try:
if key[1] == "__first__":
return self.graph.root_nodes(key[0])[0]
else: # "__latest__"
return self.graph.leaf_nodes(key[0])[0]
except IndexError:
if self.ignore_no_migrations:
return None
else:
raise ValueError(
"Dependency on app with no migrations: %s" % key[0]
)
raise ValueError("Dependency on unknown app: %s" % key[0])
def add_internal_dependencies(self, key, migration):
"""
Internal dependencies need to be added first to ensure `__first__`
dependencies find the correct root node.
"""
for parent in migration.dependencies:
# Ignore __first__ references to the same app.
if parent[0] == key[0] and parent[1] != "__first__":
self.graph.add_dependency(migration, key, parent, skip_validation=True)
def add_external_dependencies(self, key, migration):
for parent in migration.dependencies:
# Skip internal dependencies
if key[0] == parent[0]:
continue
parent = self.check_key(parent, key[0])
if parent is not None:
self.graph.add_dependency(migration, key, parent, skip_validation=True)
for child in migration.run_before:
child = self.check_key(child, key[0])
if child is not None:
self.graph.add_dependency(migration, child, key, skip_validation=True)
def build_graph(self):
"""
Build a migration dependency graph using both the disk and database.
You'll need to rebuild the graph if you apply migrations. This isn't
usually a problem as generally migration stuff runs in a one-shot process.
"""
# Load disk data
self.load_disk()
# Load database data
if self.connection is None:
self.applied_migrations = {}
else:
recorder = MigrationRecorder(self.connection)
self.applied_migrations = recorder.applied_migrations()
# To start, populate the migration graph with nodes for ALL migrations
# and their dependencies. Also make note of replacing migrations at this step.
self.graph = MigrationGraph()
self.replacements = {}
for key, migration in self.disk_migrations.items():
self.graph.add_node(key, migration)
# Replacing migrations.
if migration.replaces:
self.replacements[key] = migration
for key, migration in self.disk_migrations.items():
# Internal (same app) dependencies.
self.add_internal_dependencies(key, migration)
# Add external dependencies now that the internal ones have been resolved.
for key, migration in self.disk_migrations.items():
self.add_external_dependencies(key, migration)
# Carry out replacements where possible and if enabled.
if self.replace_migrations:
for key, migration in self.replacements.items():
# Get applied status of each of this migration's replacement
# targets.
applied_statuses = [
(target in self.applied_migrations) for target in migration.replaces
]
# The replacing migration is only marked as applied if all of
# its replacement targets are.
if all(applied_statuses):
self.applied_migrations[key] = migration
else:
self.applied_migrations.pop(key, None)
# A replacing migration can be used if either all or none of
# its replacement targets have been applied.
if all(applied_statuses) or (not any(applied_statuses)):
self.graph.remove_replaced_nodes(key, migration.replaces)
else:
# This replacing migration cannot be used because it is
# partially applied. Remove it from the graph and remap
# dependencies to it (#25945).
self.graph.remove_replacement_node(key, migration.replaces)
# Ensure the graph is consistent.
try:
self.graph.validate_consistency()
except NodeNotFoundError as exc:
# Check if the missing node could have been replaced by any squash
# migration but wasn't because the squash migration was partially
# applied before. In that case raise a more understandable exception
# (#23556).
# Get reverse replacements.
reverse_replacements = {}
for key, migration in self.replacements.items():
for replaced in migration.replaces:
reverse_replacements.setdefault(replaced, set()).add(key)
# Try to reraise exception with more detail.
if exc.node in reverse_replacements:
candidates = reverse_replacements.get(exc.node, set())
is_replaced = any(
candidate in self.graph.nodes for candidate in candidates
)
if not is_replaced:
tries = ", ".join("%s.%s" % c for c in candidates)
raise NodeNotFoundError(
"Migration {0} depends on nonexistent node ('{1}', '{2}'). "
"Django tried to replace migration {1}.{2} with any of [{3}] "
"but wasn't able to because some of the replaced migrations "
"are already applied.".format(
exc.origin, exc.node[0], exc.node[1], tries
),
exc.node,
) from exc
raise
self.graph.ensure_not_cyclic()
def check_consistent_history(self, connection):
"""
Raise InconsistentMigrationHistory if any applied migrations have
unapplied dependencies.
"""
recorder = MigrationRecorder(connection)
applied = recorder.applied_migrations()
for migration in applied:
# If the migration is unknown, skip it.
if migration not in self.graph.nodes:
continue
for parent in self.graph.node_map[migration].parents:
if parent not in applied:
# Skip unapplied squashed migrations that have all of their
# `replaces` applied.
if parent in self.replacements:
if all(
m in applied for m in self.replacements[parent].replaces
):
continue
raise InconsistentMigrationHistory(
"Migration {}.{} is applied before its dependency "
"{}.{} on database '{}'.".format(
migration[0],
migration[1],
parent[0],
parent[1],
connection.alias,
)
)
def detect_conflicts(self):
"""
Look through the loaded graph and detect any conflicts - apps
with more than one leaf migration. Return a dict of the app labels
that conflict with the migration names that conflict.
"""
seen_apps = {}
conflicting_apps = set()
for app_label, migration_name in self.graph.leaf_nodes():
if app_label in seen_apps:
conflicting_apps.add(app_label)
seen_apps.setdefault(app_label, set()).add(migration_name)
return {
app_label: sorted(seen_apps[app_label]) for app_label in conflicting_apps
}
def project_state(self, nodes=None, at_end=True):
"""
Return a ProjectState object representing the most recent state
that the loaded migrations represent.
See graph.make_state() for the meaning of "nodes" and "at_end".
"""
return self.graph.make_state(
nodes=nodes, at_end=at_end, real_apps=self.unmigrated_apps
)
def collect_sql(self, plan):
"""
Take a migration plan and return a list of collected SQL statements
that represent the best-efforts version of that plan.
"""
statements = []
state = None
for migration, backwards in plan:
with self.connection.schema_editor(
collect_sql=True, atomic=migration.atomic
) as schema_editor:
if state is None:
state = self.project_state(
(migration.app_label, migration.name), at_end=False
)
if not backwards:
state = migration.apply(state, schema_editor, collect_sql=True)
else:
state = migration.unapply(state, schema_editor, collect_sql=True)
statements.extend(schema_editor.collected_sql)
return statements
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/loader.py
|
Python
|
mit
| 16,863 |
import re
from django.db.migrations.utils import get_migration_name_timestamp
from django.db.transaction import atomic
from .exceptions import IrreversibleError
class Migration:
"""
The base class for all migrations.
Migration files will import this from django.db.migrations.Migration
and subclass it as a class called Migration. It will have one or more
of the following attributes:
- operations: A list of Operation instances, probably from
django.db.migrations.operations
- dependencies: A list of tuples of (app_path, migration_name)
- run_before: A list of tuples of (app_path, migration_name)
- replaces: A list of migration_names
Note that all migrations come out of migrations and into the Loader or
Graph as instances, having been initialized with their app label and name.
"""
# Operations to apply during this migration, in order.
operations = []
# Other migrations that should be run before this migration.
# Should be a list of (app, migration_name).
dependencies = []
# Other migrations that should be run after this one (i.e. have
# this migration added to their dependencies). Useful to make third-party
# apps' migrations run after your AUTH_USER replacement, for example.
run_before = []
# Migration names in this app that this migration replaces. If this is
# non-empty, this migration will only be applied if all these migrations
# are not applied.
replaces = []
# Is this an initial migration? Initial migrations are skipped on
# --fake-initial if the table or fields already exist. If None, check if
# the migration has any dependencies to determine if there are dependencies
# to tell if db introspection needs to be done. If True, always perform
# introspection. If False, never perform introspection.
initial = None
# Whether to wrap the whole migration in a transaction. Only has an effect
# on database backends which support transactional DDL.
atomic = True
def __init__(self, name, app_label):
self.name = name
self.app_label = app_label
# Copy dependencies & other attrs as we might mutate them at runtime
self.operations = list(self.__class__.operations)
self.dependencies = list(self.__class__.dependencies)
self.run_before = list(self.__class__.run_before)
self.replaces = list(self.__class__.replaces)
def __eq__(self, other):
return (
isinstance(other, Migration)
and self.name == other.name
and self.app_label == other.app_label
)
def __repr__(self):
return "<Migration %s.%s>" % (self.app_label, self.name)
def __str__(self):
return "%s.%s" % (self.app_label, self.name)
def __hash__(self):
return hash("%s.%s" % (self.app_label, self.name))
def mutate_state(self, project_state, preserve=True):
"""
Take a ProjectState and return a new one with the migration's
operations applied to it. Preserve the original object state by
default and return a mutated state from a copy.
"""
new_state = project_state
if preserve:
new_state = project_state.clone()
for operation in self.operations:
operation.state_forwards(self.app_label, new_state)
return new_state
def apply(self, project_state, schema_editor, collect_sql=False):
"""
Take a project_state representing all migrations prior to this one
and a schema_editor for a live database and apply the migration
in a forwards order.
Return the resulting project state for efficient reuse by following
Migrations.
"""
for operation in self.operations:
# If this operation cannot be represented as SQL, place a comment
# there instead
if collect_sql:
schema_editor.collected_sql.append("--")
schema_editor.collected_sql.append("-- %s" % operation.describe())
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
schema_editor.collected_sql.append(
"-- THIS OPERATION CANNOT BE WRITTEN AS SQL"
)
continue
collected_sql_before = len(schema_editor.collected_sql)
# Save the state before the operation has run
old_state = project_state.clone()
operation.state_forwards(self.app_label, project_state)
# Run the operation
atomic_operation = operation.atomic or (
self.atomic and operation.atomic is not False
)
if not schema_editor.atomic_migration and atomic_operation:
# Force a transaction on a non-transactional-DDL backend or an
# atomic operation inside a non-atomic migration.
with atomic(schema_editor.connection.alias):
operation.database_forwards(
self.app_label, schema_editor, old_state, project_state
)
else:
# Normal behaviour
operation.database_forwards(
self.app_label, schema_editor, old_state, project_state
)
if collect_sql and collected_sql_before == len(schema_editor.collected_sql):
schema_editor.collected_sql.append("-- (no-op)")
return project_state
def unapply(self, project_state, schema_editor, collect_sql=False):
"""
Take a project_state representing all migrations prior to this one
and a schema_editor for a live database and apply the migration
in a reverse order.
The backwards migration process consists of two phases:
1. The intermediate states from right before the first until right
after the last operation inside this migration are preserved.
2. The operations are applied in reverse order using the states
recorded in step 1.
"""
# Construct all the intermediate states we need for a reverse migration
to_run = []
new_state = project_state
# Phase 1
for operation in self.operations:
# If it's irreversible, error out
if not operation.reversible:
raise IrreversibleError(
"Operation %s in %s is not reversible" % (operation, self)
)
# Preserve new state from previous run to not tamper the same state
# over all operations
new_state = new_state.clone()
old_state = new_state.clone()
operation.state_forwards(self.app_label, new_state)
to_run.insert(0, (operation, old_state, new_state))
# Phase 2
for operation, to_state, from_state in to_run:
if collect_sql:
schema_editor.collected_sql.append("--")
schema_editor.collected_sql.append("-- %s" % operation.describe())
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
schema_editor.collected_sql.append(
"-- THIS OPERATION CANNOT BE WRITTEN AS SQL"
)
continue
collected_sql_before = len(schema_editor.collected_sql)
atomic_operation = operation.atomic or (
self.atomic and operation.atomic is not False
)
if not schema_editor.atomic_migration and atomic_operation:
# Force a transaction on a non-transactional-DDL backend or an
# atomic operation inside a non-atomic migration.
with atomic(schema_editor.connection.alias):
operation.database_backwards(
self.app_label, schema_editor, from_state, to_state
)
else:
# Normal behaviour
operation.database_backwards(
self.app_label, schema_editor, from_state, to_state
)
if collect_sql and collected_sql_before == len(schema_editor.collected_sql):
schema_editor.collected_sql.append("-- (no-op)")
return project_state
def suggest_name(self):
"""
Suggest a name for the operations this migration might represent. Names
are not guaranteed to be unique, but put some effort into the fallback
name to avoid VCS conflicts if possible.
"""
if self.initial:
return "initial"
raw_fragments = [op.migration_name_fragment for op in self.operations]
fragments = [re.sub(r"\W+", "_", name) for name in raw_fragments if name]
if not fragments or len(fragments) != len(self.operations):
return "auto_%s" % get_migration_name_timestamp()
name = fragments[0]
for fragment in fragments[1:]:
new_name = f"{name}_{fragment}"
if len(new_name) > 52:
name = f"{name}_and_more"
break
name = new_name
return name
class SwappableTuple(tuple):
"""
Subclass of tuple so Django can tell this was originally a swappable
dependency when it reads the migration file.
"""
def __new__(cls, value, setting):
self = tuple.__new__(cls, value)
self.setting = setting
return self
def swappable_dependency(value):
"""Turn a setting value into a dependency."""
return SwappableTuple((value.split(".", 1)[0], "__first__"), value)
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/migration.py
|
Python
|
mit
| 9,767 |
from .fields import AddField, AlterField, RemoveField, RenameField
from .models import (
AddConstraint,
AddIndex,
AlterIndexTogether,
AlterModelManagers,
AlterModelOptions,
AlterModelTable,
AlterModelTableComment,
AlterOrderWithRespectTo,
AlterUniqueTogether,
CreateModel,
DeleteModel,
RemoveConstraint,
RemoveIndex,
RenameIndex,
RenameModel,
)
from .special import RunPython, RunSQL, SeparateDatabaseAndState
__all__ = [
"CreateModel",
"DeleteModel",
"AlterModelTable",
"AlterModelTableComment",
"AlterUniqueTogether",
"RenameModel",
"AlterIndexTogether",
"AlterModelOptions",
"AddIndex",
"RemoveIndex",
"RenameIndex",
"AddField",
"RemoveField",
"AlterField",
"RenameField",
"AddConstraint",
"RemoveConstraint",
"SeparateDatabaseAndState",
"RunSQL",
"RunPython",
"AlterOrderWithRespectTo",
"AlterModelManagers",
]
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/operations/__init__.py
|
Python
|
mit
| 964 |
from django.db import router
class Operation:
"""
Base class for migration operations.
It's responsible for both mutating the in-memory model state
(see db/migrations/state.py) to represent what it performs, as well
as actually performing it against a live database.
Note that some operations won't modify memory state at all (e.g. data
copying operations), and some will need their modifications to be
optionally specified by the user (e.g. custom Python code snippets)
Due to the way this class deals with deconstruction, it should be
considered immutable.
"""
# If this migration can be run in reverse.
# Some operations are impossible to reverse, like deleting data.
reversible = True
# Can this migration be represented as SQL? (things like RunPython cannot)
reduces_to_sql = True
# Should this operation be forced as atomic even on backends with no
# DDL transaction support (i.e., does it have no DDL, like RunPython)
atomic = False
# Should this operation be considered safe to elide and optimize across?
elidable = False
serialization_expand_args = []
def __new__(cls, *args, **kwargs):
# We capture the arguments to make returning them trivial
self = object.__new__(cls)
self._constructor_args = (args, kwargs)
return self
def deconstruct(self):
"""
Return a 3-tuple of class import path (or just name if it lives
under django.db.migrations), positional arguments, and keyword
arguments.
"""
return (
self.__class__.__name__,
self._constructor_args[0],
self._constructor_args[1],
)
def state_forwards(self, app_label, state):
"""
Take the state from the previous migration, and mutate it
so that it matches what this migration would perform.
"""
raise NotImplementedError(
"subclasses of Operation must provide a state_forwards() method"
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
"""
Perform the mutation on the database schema in the normal
(forwards) direction.
"""
raise NotImplementedError(
"subclasses of Operation must provide a database_forwards() method"
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
"""
Perform the mutation on the database schema in the reverse
direction - e.g. if this were CreateModel, it would in fact
drop the model's table.
"""
raise NotImplementedError(
"subclasses of Operation must provide a database_backwards() method"
)
def describe(self):
"""
Output a brief summary of what the action does.
"""
return "%s: %s" % (self.__class__.__name__, self._constructor_args)
@property
def migration_name_fragment(self):
"""
A filename part suitable for automatically naming a migration
containing this operation, or None if not applicable.
"""
return None
def references_model(self, name, app_label):
"""
Return True if there is a chance this operation references the given
model name (as a string), with an app label for accuracy.
Used for optimization. If in doubt, return True;
returning a false positive will merely make the optimizer a little
less efficient, while returning a false negative may result in an
unusable optimized migration.
"""
return True
def references_field(self, model_name, name, app_label):
"""
Return True if there is a chance this operation references the given
field name, with an app label for accuracy.
Used for optimization. If in doubt, return True.
"""
return self.references_model(model_name, app_label)
def allow_migrate_model(self, connection_alias, model):
"""
Return whether or not a model may be migrated.
This is a thin wrapper around router.allow_migrate_model() that
preemptively rejects any proxy, swapped out, or unmanaged model.
"""
if not model._meta.can_migrate(connection_alias):
return False
return router.allow_migrate_model(connection_alias, model)
def reduce(self, operation, app_label):
"""
Return either a list of operations the actual operation should be
replaced with or a boolean that indicates whether or not the specified
operation can be optimized across.
"""
if self.elidable:
return [operation]
elif operation.elidable:
return [self]
return False
def __repr__(self):
return "<%s %s%s>" % (
self.__class__.__name__,
", ".join(map(repr, self._constructor_args[0])),
",".join(" %s=%r" % x for x in self._constructor_args[1].items()),
)
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/operations/base.py
|
Python
|
mit
| 5,082 |
from django.db.migrations.utils import field_references
from django.db.models import NOT_PROVIDED
from django.utils.functional import cached_property
from .base import Operation
class FieldOperation(Operation):
def __init__(self, model_name, name, field=None):
self.model_name = model_name
self.name = name
self.field = field
@cached_property
def model_name_lower(self):
return self.model_name.lower()
@cached_property
def name_lower(self):
return self.name.lower()
def is_same_model_operation(self, operation):
return self.model_name_lower == operation.model_name_lower
def is_same_field_operation(self, operation):
return (
self.is_same_model_operation(operation)
and self.name_lower == operation.name_lower
)
def references_model(self, name, app_label):
name_lower = name.lower()
if name_lower == self.model_name_lower:
return True
if self.field:
return bool(
field_references(
(app_label, self.model_name_lower),
self.field,
(app_label, name_lower),
)
)
return False
def references_field(self, model_name, name, app_label):
model_name_lower = model_name.lower()
# Check if this operation locally references the field.
if model_name_lower == self.model_name_lower:
if name == self.name:
return True
elif (
self.field
and hasattr(self.field, "from_fields")
and name in self.field.from_fields
):
return True
# Check if this operation remotely references the field.
if self.field is None:
return False
return bool(
field_references(
(app_label, self.model_name_lower),
self.field,
(app_label, model_name_lower),
name,
)
)
def reduce(self, operation, app_label):
return super().reduce(operation, app_label) or not operation.references_field(
self.model_name, self.name, app_label
)
class AddField(FieldOperation):
"""Add a field to a model."""
def __init__(self, model_name, name, field, preserve_default=True):
self.preserve_default = preserve_default
super().__init__(model_name, name, field)
def deconstruct(self):
kwargs = {
"model_name": self.model_name,
"name": self.name,
"field": self.field,
}
if self.preserve_default is not True:
kwargs["preserve_default"] = self.preserve_default
return (self.__class__.__name__, [], kwargs)
def state_forwards(self, app_label, state):
state.add_field(
app_label,
self.model_name_lower,
self.name,
self.field,
self.preserve_default,
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
field = to_model._meta.get_field(self.name)
if not self.preserve_default:
field.default = self.field.default
schema_editor.add_field(
from_model,
field,
)
if not self.preserve_default:
field.default = NOT_PROVIDED
def database_backwards(self, app_label, schema_editor, from_state, to_state):
from_model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, from_model):
schema_editor.remove_field(
from_model, from_model._meta.get_field(self.name)
)
def describe(self):
return "Add field %s to %s" % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return "%s_%s" % (self.model_name_lower, self.name_lower)
def reduce(self, operation, app_label):
if isinstance(operation, FieldOperation) and self.is_same_field_operation(
operation
):
if isinstance(operation, AlterField):
return [
AddField(
model_name=self.model_name,
name=operation.name,
field=operation.field,
),
]
elif isinstance(operation, RemoveField):
return []
elif isinstance(operation, RenameField):
return [
AddField(
model_name=self.model_name,
name=operation.new_name,
field=self.field,
),
]
return super().reduce(operation, app_label)
class RemoveField(FieldOperation):
"""Remove a field from a model."""
def deconstruct(self):
kwargs = {
"model_name": self.model_name,
"name": self.name,
}
return (self.__class__.__name__, [], kwargs)
def state_forwards(self, app_label, state):
state.remove_field(app_label, self.model_name_lower, self.name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
from_model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, from_model):
schema_editor.remove_field(
from_model, from_model._meta.get_field(self.name)
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.add_field(from_model, to_model._meta.get_field(self.name))
def describe(self):
return "Remove field %s from %s" % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return "remove_%s_%s" % (self.model_name_lower, self.name_lower)
def reduce(self, operation, app_label):
from .models import DeleteModel
if (
isinstance(operation, DeleteModel)
and operation.name_lower == self.model_name_lower
):
return [operation]
return super().reduce(operation, app_label)
class AlterField(FieldOperation):
"""
Alter a field's database column (e.g. null, max_length) to the provided
new field.
"""
def __init__(self, model_name, name, field, preserve_default=True):
self.preserve_default = preserve_default
super().__init__(model_name, name, field)
def deconstruct(self):
kwargs = {
"model_name": self.model_name,
"name": self.name,
"field": self.field,
}
if self.preserve_default is not True:
kwargs["preserve_default"] = self.preserve_default
return (self.__class__.__name__, [], kwargs)
def state_forwards(self, app_label, state):
state.alter_field(
app_label,
self.model_name_lower,
self.name,
self.field,
self.preserve_default,
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
from_field = from_model._meta.get_field(self.name)
to_field = to_model._meta.get_field(self.name)
if not self.preserve_default:
to_field.default = self.field.default
schema_editor.alter_field(from_model, from_field, to_field)
if not self.preserve_default:
to_field.default = NOT_PROVIDED
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.database_forwards(app_label, schema_editor, from_state, to_state)
def describe(self):
return "Alter field %s on %s" % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return "alter_%s_%s" % (self.model_name_lower, self.name_lower)
def reduce(self, operation, app_label):
if isinstance(operation, RemoveField) and self.is_same_field_operation(
operation
):
return [operation]
elif (
isinstance(operation, RenameField)
and self.is_same_field_operation(operation)
and self.field.db_column is None
):
return [
operation,
AlterField(
model_name=self.model_name,
name=operation.new_name,
field=self.field,
),
]
return super().reduce(operation, app_label)
class RenameField(FieldOperation):
"""Rename a field on the model. Might affect db_column too."""
def __init__(self, model_name, old_name, new_name):
self.old_name = old_name
self.new_name = new_name
super().__init__(model_name, old_name)
@cached_property
def old_name_lower(self):
return self.old_name.lower()
@cached_property
def new_name_lower(self):
return self.new_name.lower()
def deconstruct(self):
kwargs = {
"model_name": self.model_name,
"old_name": self.old_name,
"new_name": self.new_name,
}
return (self.__class__.__name__, [], kwargs)
def state_forwards(self, app_label, state):
state.rename_field(
app_label, self.model_name_lower, self.old_name, self.new_name
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.alter_field(
from_model,
from_model._meta.get_field(self.old_name),
to_model._meta.get_field(self.new_name),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.alter_field(
from_model,
from_model._meta.get_field(self.new_name),
to_model._meta.get_field(self.old_name),
)
def describe(self):
return "Rename field %s on %s to %s" % (
self.old_name,
self.model_name,
self.new_name,
)
@property
def migration_name_fragment(self):
return "rename_%s_%s_%s" % (
self.old_name_lower,
self.model_name_lower,
self.new_name_lower,
)
def references_field(self, model_name, name, app_label):
return self.references_model(model_name, app_label) and (
name.lower() == self.old_name_lower or name.lower() == self.new_name_lower
)
def reduce(self, operation, app_label):
if (
isinstance(operation, RenameField)
and self.is_same_model_operation(operation)
and self.new_name_lower == operation.old_name_lower
):
return [
RenameField(
self.model_name,
self.old_name,
operation.new_name,
),
]
# Skip `FieldOperation.reduce` as we want to run `references_field`
# against self.old_name and self.new_name.
return super(FieldOperation, self).reduce(operation, app_label) or not (
operation.references_field(self.model_name, self.old_name, app_label)
or operation.references_field(self.model_name, self.new_name, app_label)
)
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/operations/fields.py
|
Python
|
mit
| 12,692 |
from django.db import models
from django.db.migrations.operations.base import Operation
from django.db.migrations.state import ModelState
from django.db.migrations.utils import field_references, resolve_relation
from django.db.models.options import normalize_together
from django.utils.functional import cached_property
from .fields import AddField, AlterField, FieldOperation, RemoveField, RenameField
def _check_for_duplicates(arg_name, objs):
used_vals = set()
for val in objs:
if val in used_vals:
raise ValueError(
"Found duplicate value %s in CreateModel %s argument." % (val, arg_name)
)
used_vals.add(val)
class ModelOperation(Operation):
def __init__(self, name):
self.name = name
@cached_property
def name_lower(self):
return self.name.lower()
def references_model(self, name, app_label):
return name.lower() == self.name_lower
def reduce(self, operation, app_label):
return super().reduce(operation, app_label) or self.can_reduce_through(
operation, app_label
)
def can_reduce_through(self, operation, app_label):
return not operation.references_model(self.name, app_label)
class CreateModel(ModelOperation):
"""Create a model's table."""
serialization_expand_args = ["fields", "options", "managers"]
def __init__(self, name, fields, options=None, bases=None, managers=None):
self.fields = fields
self.options = options or {}
self.bases = bases or (models.Model,)
self.managers = managers or []
super().__init__(name)
# Sanity-check that there are no duplicated field names, bases, or
# manager names
_check_for_duplicates("fields", (name for name, _ in self.fields))
_check_for_duplicates(
"bases",
(
base._meta.label_lower
if hasattr(base, "_meta")
else base.lower()
if isinstance(base, str)
else base
for base in self.bases
),
)
_check_for_duplicates("managers", (name for name, _ in self.managers))
def deconstruct(self):
kwargs = {
"name": self.name,
"fields": self.fields,
}
if self.options:
kwargs["options"] = self.options
if self.bases and self.bases != (models.Model,):
kwargs["bases"] = self.bases
if self.managers and self.managers != [("objects", models.Manager())]:
kwargs["managers"] = self.managers
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
state.add_model(
ModelState(
app_label,
self.name,
list(self.fields),
dict(self.options),
tuple(self.bases),
list(self.managers),
)
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.create_model(model)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.delete_model(model)
def describe(self):
return "Create %smodel %s" % (
"proxy " if self.options.get("proxy", False) else "",
self.name,
)
@property
def migration_name_fragment(self):
return self.name_lower
def references_model(self, name, app_label):
name_lower = name.lower()
if name_lower == self.name_lower:
return True
# Check we didn't inherit from the model
reference_model_tuple = (app_label, name_lower)
for base in self.bases:
if (
base is not models.Model
and isinstance(base, (models.base.ModelBase, str))
and resolve_relation(base, app_label) == reference_model_tuple
):
return True
# Check we have no FKs/M2Ms with it
for _name, field in self.fields:
if field_references(
(app_label, self.name_lower), field, reference_model_tuple
):
return True
return False
def reduce(self, operation, app_label):
if (
isinstance(operation, DeleteModel)
and self.name_lower == operation.name_lower
and not self.options.get("proxy", False)
):
return []
elif (
isinstance(operation, RenameModel)
and self.name_lower == operation.old_name_lower
):
return [
CreateModel(
operation.new_name,
fields=self.fields,
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif (
isinstance(operation, AlterModelOptions)
and self.name_lower == operation.name_lower
):
options = {**self.options, **operation.options}
for key in operation.ALTER_OPTION_KEYS:
if key not in operation.options:
options.pop(key, None)
return [
CreateModel(
self.name,
fields=self.fields,
options=options,
bases=self.bases,
managers=self.managers,
),
]
elif (
isinstance(operation, AlterModelManagers)
and self.name_lower == operation.name_lower
):
return [
CreateModel(
self.name,
fields=self.fields,
options=self.options,
bases=self.bases,
managers=operation.managers,
),
]
elif (
isinstance(operation, AlterTogetherOptionOperation)
and self.name_lower == operation.name_lower
):
return [
CreateModel(
self.name,
fields=self.fields,
options={
**self.options,
**{operation.option_name: operation.option_value},
},
bases=self.bases,
managers=self.managers,
),
]
elif (
isinstance(operation, AlterOrderWithRespectTo)
and self.name_lower == operation.name_lower
):
return [
CreateModel(
self.name,
fields=self.fields,
options={
**self.options,
"order_with_respect_to": operation.order_with_respect_to,
},
bases=self.bases,
managers=self.managers,
),
]
elif (
isinstance(operation, FieldOperation)
and self.name_lower == operation.model_name_lower
):
if isinstance(operation, AddField):
return [
CreateModel(
self.name,
fields=self.fields + [(operation.name, operation.field)],
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, AlterField):
return [
CreateModel(
self.name,
fields=[
(n, operation.field if n == operation.name else v)
for n, v in self.fields
],
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, RemoveField):
options = self.options.copy()
for option_name in ("unique_together", "index_together"):
option = options.pop(option_name, None)
if option:
option = set(
filter(
bool,
(
tuple(
f for f in fields if f != operation.name_lower
)
for fields in option
),
)
)
if option:
options[option_name] = option
order_with_respect_to = options.get("order_with_respect_to")
if order_with_respect_to == operation.name_lower:
del options["order_with_respect_to"]
return [
CreateModel(
self.name,
fields=[
(n, v)
for n, v in self.fields
if n.lower() != operation.name_lower
],
options=options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, RenameField):
options = self.options.copy()
for option_name in ("unique_together", "index_together"):
option = options.get(option_name)
if option:
options[option_name] = {
tuple(
operation.new_name if f == operation.old_name else f
for f in fields
)
for fields in option
}
order_with_respect_to = options.get("order_with_respect_to")
if order_with_respect_to == operation.old_name:
options["order_with_respect_to"] = operation.new_name
return [
CreateModel(
self.name,
fields=[
(operation.new_name if n == operation.old_name else n, v)
for n, v in self.fields
],
options=options,
bases=self.bases,
managers=self.managers,
),
]
elif (
isinstance(operation, IndexOperation)
and self.name_lower == operation.model_name_lower
):
if isinstance(operation, AddIndex):
return [
CreateModel(
self.name,
fields=self.fields,
options={
**self.options,
"indexes": [
*self.options.get("indexes", []),
operation.index,
],
},
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, RemoveIndex):
options_indexes = [
index
for index in self.options.get("indexes", [])
if index.name != operation.name
]
return [
CreateModel(
self.name,
fields=self.fields,
options={
**self.options,
"indexes": options_indexes,
},
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, RenameIndex) and operation.old_fields:
options_index_together = {
fields
for fields in self.options.get("index_together", [])
if fields != operation.old_fields
}
if options_index_together:
self.options["index_together"] = options_index_together
else:
self.options.pop("index_together", None)
return [
CreateModel(
self.name,
fields=self.fields,
options={
**self.options,
"indexes": [
*self.options.get("indexes", []),
models.Index(
fields=operation.old_fields, name=operation.new_name
),
],
},
bases=self.bases,
managers=self.managers,
),
]
return super().reduce(operation, app_label)
class DeleteModel(ModelOperation):
"""Drop a model's table."""
def deconstruct(self):
kwargs = {
"name": self.name,
}
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
state.remove_model(app_label, self.name_lower)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.delete_model(model)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.create_model(model)
def references_model(self, name, app_label):
# The deleted model could be referencing the specified model through
# related fields.
return True
def describe(self):
return "Delete model %s" % self.name
@property
def migration_name_fragment(self):
return "delete_%s" % self.name_lower
class RenameModel(ModelOperation):
"""Rename a model."""
def __init__(self, old_name, new_name):
self.old_name = old_name
self.new_name = new_name
super().__init__(old_name)
@cached_property
def old_name_lower(self):
return self.old_name.lower()
@cached_property
def new_name_lower(self):
return self.new_name.lower()
def deconstruct(self):
kwargs = {
"old_name": self.old_name,
"new_name": self.new_name,
}
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
state.rename_model(app_label, self.old_name, self.new_name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.new_name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.old_name)
# Move the main table
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.db_table,
)
# Alter the fields pointing to us
for related_object in old_model._meta.related_objects:
if related_object.related_model == old_model:
model = new_model
related_key = (app_label, self.new_name_lower)
else:
model = related_object.related_model
related_key = (
related_object.related_model._meta.app_label,
related_object.related_model._meta.model_name,
)
to_field = to_state.apps.get_model(*related_key)._meta.get_field(
related_object.field.name
)
schema_editor.alter_field(
model,
related_object.field,
to_field,
)
# Rename M2M fields whose name is based on this model's name.
fields = zip(
old_model._meta.local_many_to_many, new_model._meta.local_many_to_many
)
for old_field, new_field in fields:
# Skip self-referential fields as these are renamed above.
if (
new_field.model == new_field.related_model
or not new_field.remote_field.through._meta.auto_created
):
continue
# Rename columns and the M2M table.
schema_editor._alter_many_to_many(
new_model,
old_field,
new_field,
strict=False,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.new_name_lower, self.old_name_lower = (
self.old_name_lower,
self.new_name_lower,
)
self.new_name, self.old_name = self.old_name, self.new_name
self.database_forwards(app_label, schema_editor, from_state, to_state)
self.new_name_lower, self.old_name_lower = (
self.old_name_lower,
self.new_name_lower,
)
self.new_name, self.old_name = self.old_name, self.new_name
def references_model(self, name, app_label):
return (
name.lower() == self.old_name_lower or name.lower() == self.new_name_lower
)
def describe(self):
return "Rename model %s to %s" % (self.old_name, self.new_name)
@property
def migration_name_fragment(self):
return "rename_%s_%s" % (self.old_name_lower, self.new_name_lower)
def reduce(self, operation, app_label):
if (
isinstance(operation, RenameModel)
and self.new_name_lower == operation.old_name_lower
):
return [
RenameModel(
self.old_name,
operation.new_name,
),
]
# Skip `ModelOperation.reduce` as we want to run `references_model`
# against self.new_name.
return super(ModelOperation, self).reduce(
operation, app_label
) or not operation.references_model(self.new_name, app_label)
class ModelOptionOperation(ModelOperation):
def reduce(self, operation, app_label):
if (
isinstance(operation, (self.__class__, DeleteModel))
and self.name_lower == operation.name_lower
):
return [operation]
return super().reduce(operation, app_label)
class AlterModelTable(ModelOptionOperation):
"""Rename a model's table."""
def __init__(self, name, table):
self.table = table
super().__init__(name)
def deconstruct(self):
kwargs = {
"name": self.name,
"table": self.table,
}
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
state.alter_model_options(app_label, self.name_lower, {"db_table": self.table})
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.name)
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.db_table,
)
# Rename M2M fields whose name is based on this model's db_table
for old_field, new_field in zip(
old_model._meta.local_many_to_many, new_model._meta.local_many_to_many
):
if new_field.remote_field.through._meta.auto_created:
schema_editor.alter_db_table(
new_field.remote_field.through,
old_field.remote_field.through._meta.db_table,
new_field.remote_field.through._meta.db_table,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def describe(self):
return "Rename table for %s to %s" % (
self.name,
self.table if self.table is not None else "(default)",
)
@property
def migration_name_fragment(self):
return "alter_%s_table" % self.name_lower
class AlterModelTableComment(ModelOptionOperation):
def __init__(self, name, table_comment):
self.table_comment = table_comment
super().__init__(name)
def deconstruct(self):
kwargs = {
"name": self.name,
"table_comment": self.table_comment,
}
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
state.alter_model_options(
app_label, self.name_lower, {"db_table_comment": self.table_comment}
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.name)
schema_editor.alter_db_table_comment(
new_model,
old_model._meta.db_table_comment,
new_model._meta.db_table_comment,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def describe(self):
return f"Alter {self.name} table comment"
@property
def migration_name_fragment(self):
return f"alter_{self.name_lower}_table_comment"
class AlterTogetherOptionOperation(ModelOptionOperation):
option_name = None
def __init__(self, name, option_value):
if option_value:
option_value = set(normalize_together(option_value))
setattr(self, self.option_name, option_value)
super().__init__(name)
@cached_property
def option_value(self):
return getattr(self, self.option_name)
def deconstruct(self):
kwargs = {
"name": self.name,
self.option_name: self.option_value,
}
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
state.alter_model_options(
app_label,
self.name_lower,
{self.option_name: self.option_value},
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.name)
alter_together = getattr(schema_editor, "alter_%s" % self.option_name)
alter_together(
new_model,
getattr(old_model._meta, self.option_name, set()),
getattr(new_model._meta, self.option_name, set()),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_field(self, model_name, name, app_label):
return self.references_model(model_name, app_label) and (
not self.option_value
or any((name in fields) for fields in self.option_value)
)
def describe(self):
return "Alter %s for %s (%s constraint(s))" % (
self.option_name,
self.name,
len(self.option_value or ""),
)
@property
def migration_name_fragment(self):
return "alter_%s_%s" % (self.name_lower, self.option_name)
def can_reduce_through(self, operation, app_label):
return super().can_reduce_through(operation, app_label) or (
isinstance(operation, AlterTogetherOptionOperation)
and type(operation) is not type(self)
)
class AlterUniqueTogether(AlterTogetherOptionOperation):
"""
Change the value of unique_together to the target one.
Input value of unique_together must be a set of tuples.
"""
option_name = "unique_together"
def __init__(self, name, unique_together):
super().__init__(name, unique_together)
class AlterIndexTogether(AlterTogetherOptionOperation):
"""
Change the value of index_together to the target one.
Input value of index_together must be a set of tuples.
"""
option_name = "index_together"
def __init__(self, name, index_together):
super().__init__(name, index_together)
class AlterOrderWithRespectTo(ModelOptionOperation):
"""Represent a change with the order_with_respect_to option."""
option_name = "order_with_respect_to"
def __init__(self, name, order_with_respect_to):
self.order_with_respect_to = order_with_respect_to
super().__init__(name)
def deconstruct(self):
kwargs = {
"name": self.name,
"order_with_respect_to": self.order_with_respect_to,
}
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
state.alter_model_options(
app_label,
self.name_lower,
{self.option_name: self.order_with_respect_to},
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.name)
# Remove a field if we need to
if (
from_model._meta.order_with_respect_to
and not to_model._meta.order_with_respect_to
):
schema_editor.remove_field(
from_model, from_model._meta.get_field("_order")
)
# Add a field if we need to (altering the column is untouched as
# it's likely a rename)
elif (
to_model._meta.order_with_respect_to
and not from_model._meta.order_with_respect_to
):
field = to_model._meta.get_field("_order")
if not field.has_default():
field.default = 0
schema_editor.add_field(
from_model,
field,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_field(self, model_name, name, app_label):
return self.references_model(model_name, app_label) and (
self.order_with_respect_to is None or name == self.order_with_respect_to
)
def describe(self):
return "Set order_with_respect_to on %s to %s" % (
self.name,
self.order_with_respect_to,
)
@property
def migration_name_fragment(self):
return "alter_%s_order_with_respect_to" % self.name_lower
class AlterModelOptions(ModelOptionOperation):
"""
Set new model options that don't directly affect the database schema
(like verbose_name, permissions, ordering). Python code in migrations
may still need them.
"""
# Model options we want to compare and preserve in an AlterModelOptions op
ALTER_OPTION_KEYS = [
"base_manager_name",
"default_manager_name",
"default_related_name",
"get_latest_by",
"managed",
"ordering",
"permissions",
"default_permissions",
"select_on_save",
"verbose_name",
"verbose_name_plural",
]
def __init__(self, name, options):
self.options = options
super().__init__(name)
def deconstruct(self):
kwargs = {
"name": self.name,
"options": self.options,
}
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
state.alter_model_options(
app_label,
self.name_lower,
self.options,
self.ALTER_OPTION_KEYS,
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
pass
def database_backwards(self, app_label, schema_editor, from_state, to_state):
pass
def describe(self):
return "Change Meta options on %s" % self.name
@property
def migration_name_fragment(self):
return "alter_%s_options" % self.name_lower
class AlterModelManagers(ModelOptionOperation):
"""Alter the model's managers."""
serialization_expand_args = ["managers"]
def __init__(self, name, managers):
self.managers = managers
super().__init__(name)
def deconstruct(self):
return (self.__class__.__qualname__, [self.name, self.managers], {})
def state_forwards(self, app_label, state):
state.alter_model_managers(app_label, self.name_lower, self.managers)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
pass
def database_backwards(self, app_label, schema_editor, from_state, to_state):
pass
def describe(self):
return "Change managers on %s" % self.name
@property
def migration_name_fragment(self):
return "alter_%s_managers" % self.name_lower
class IndexOperation(Operation):
option_name = "indexes"
@cached_property
def model_name_lower(self):
return self.model_name.lower()
class AddIndex(IndexOperation):
"""Add an index on a model."""
def __init__(self, model_name, index):
self.model_name = model_name
if not index.name:
raise ValueError(
"Indexes passed to AddIndex operations require a name "
"argument. %r doesn't have one." % index
)
self.index = index
def state_forwards(self, app_label, state):
state.add_index(app_label, self.model_name_lower, self.index)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.add_index(model, self.index)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.remove_index(model, self.index)
def deconstruct(self):
kwargs = {
"model_name": self.model_name,
"index": self.index,
}
return (
self.__class__.__qualname__,
[],
kwargs,
)
def describe(self):
if self.index.expressions:
return "Create index %s on %s on model %s" % (
self.index.name,
", ".join([str(expression) for expression in self.index.expressions]),
self.model_name,
)
return "Create index %s on field(s) %s of model %s" % (
self.index.name,
", ".join(self.index.fields),
self.model_name,
)
@property
def migration_name_fragment(self):
return "%s_%s" % (self.model_name_lower, self.index.name.lower())
class RemoveIndex(IndexOperation):
"""Remove an index from a model."""
def __init__(self, model_name, name):
self.model_name = model_name
self.name = name
def state_forwards(self, app_label, state):
state.remove_index(app_label, self.model_name_lower, self.name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
from_model_state = from_state.models[app_label, self.model_name_lower]
index = from_model_state.get_index_by_name(self.name)
schema_editor.remove_index(model, index)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
to_model_state = to_state.models[app_label, self.model_name_lower]
index = to_model_state.get_index_by_name(self.name)
schema_editor.add_index(model, index)
def deconstruct(self):
kwargs = {
"model_name": self.model_name,
"name": self.name,
}
return (
self.__class__.__qualname__,
[],
kwargs,
)
def describe(self):
return "Remove index %s from %s" % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return "remove_%s_%s" % (self.model_name_lower, self.name.lower())
class RenameIndex(IndexOperation):
"""Rename an index."""
def __init__(self, model_name, new_name, old_name=None, old_fields=None):
if not old_name and not old_fields:
raise ValueError(
"RenameIndex requires one of old_name and old_fields arguments to be "
"set."
)
if old_name and old_fields:
raise ValueError(
"RenameIndex.old_name and old_fields are mutually exclusive."
)
self.model_name = model_name
self.new_name = new_name
self.old_name = old_name
self.old_fields = old_fields
@cached_property
def old_name_lower(self):
return self.old_name.lower()
@cached_property
def new_name_lower(self):
return self.new_name.lower()
def deconstruct(self):
kwargs = {
"model_name": self.model_name,
"new_name": self.new_name,
}
if self.old_name:
kwargs["old_name"] = self.old_name
if self.old_fields:
kwargs["old_fields"] = self.old_fields
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
if self.old_fields:
state.add_index(
app_label,
self.model_name_lower,
models.Index(fields=self.old_fields, name=self.new_name),
)
state.remove_model_options(
app_label,
self.model_name_lower,
AlterIndexTogether.option_name,
self.old_fields,
)
else:
state.rename_index(
app_label, self.model_name_lower, self.old_name, self.new_name
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if not self.allow_migrate_model(schema_editor.connection.alias, model):
return
if self.old_fields:
from_model = from_state.apps.get_model(app_label, self.model_name)
columns = [
from_model._meta.get_field(field).column for field in self.old_fields
]
matching_index_name = schema_editor._constraint_names(
from_model, column_names=columns, index=True
)
if len(matching_index_name) != 1:
raise ValueError(
"Found wrong number (%s) of indexes for %s(%s)."
% (
len(matching_index_name),
from_model._meta.db_table,
", ".join(columns),
)
)
old_index = models.Index(
fields=self.old_fields,
name=matching_index_name[0],
)
else:
from_model_state = from_state.models[app_label, self.model_name_lower]
old_index = from_model_state.get_index_by_name(self.old_name)
# Don't alter when the index name is not changed.
if old_index.name == self.new_name:
return
to_model_state = to_state.models[app_label, self.model_name_lower]
new_index = to_model_state.get_index_by_name(self.new_name)
schema_editor.rename_index(model, old_index, new_index)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
if self.old_fields:
# Backward operation with unnamed index is a no-op.
return
self.new_name_lower, self.old_name_lower = (
self.old_name_lower,
self.new_name_lower,
)
self.new_name, self.old_name = self.old_name, self.new_name
self.database_forwards(app_label, schema_editor, from_state, to_state)
self.new_name_lower, self.old_name_lower = (
self.old_name_lower,
self.new_name_lower,
)
self.new_name, self.old_name = self.old_name, self.new_name
def describe(self):
if self.old_name:
return (
f"Rename index {self.old_name} on {self.model_name} to {self.new_name}"
)
return (
f"Rename unnamed index for {self.old_fields} on {self.model_name} to "
f"{self.new_name}"
)
@property
def migration_name_fragment(self):
if self.old_name:
return "rename_%s_%s" % (self.old_name_lower, self.new_name_lower)
return "rename_%s_%s_%s" % (
self.model_name_lower,
"_".join(self.old_fields),
self.new_name_lower,
)
def reduce(self, operation, app_label):
if (
isinstance(operation, RenameIndex)
and self.model_name_lower == operation.model_name_lower
and operation.old_name
and self.new_name_lower == operation.old_name_lower
):
return [
RenameIndex(
self.model_name,
new_name=operation.new_name,
old_name=self.old_name,
old_fields=self.old_fields,
)
]
return super().reduce(operation, app_label)
class AddConstraint(IndexOperation):
option_name = "constraints"
def __init__(self, model_name, constraint):
self.model_name = model_name
self.constraint = constraint
def state_forwards(self, app_label, state):
state.add_constraint(app_label, self.model_name_lower, self.constraint)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.add_constraint(model, self.constraint)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.remove_constraint(model, self.constraint)
def deconstruct(self):
return (
self.__class__.__name__,
[],
{
"model_name": self.model_name,
"constraint": self.constraint,
},
)
def describe(self):
return "Create constraint %s on model %s" % (
self.constraint.name,
self.model_name,
)
@property
def migration_name_fragment(self):
return "%s_%s" % (self.model_name_lower, self.constraint.name.lower())
class RemoveConstraint(IndexOperation):
option_name = "constraints"
def __init__(self, model_name, name):
self.model_name = model_name
self.name = name
def state_forwards(self, app_label, state):
state.remove_constraint(app_label, self.model_name_lower, self.name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
from_model_state = from_state.models[app_label, self.model_name_lower]
constraint = from_model_state.get_constraint_by_name(self.name)
schema_editor.remove_constraint(model, constraint)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
to_model_state = to_state.models[app_label, self.model_name_lower]
constraint = to_model_state.get_constraint_by_name(self.name)
schema_editor.add_constraint(model, constraint)
def deconstruct(self):
return (
self.__class__.__name__,
[],
{
"model_name": self.model_name,
"name": self.name,
},
)
def describe(self):
return "Remove constraint %s from model %s" % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return "remove_%s_%s" % (self.model_name_lower, self.name.lower())
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/operations/models.py
|
Python
|
mit
| 42,988 |
from django.db import router
from .base import Operation
class SeparateDatabaseAndState(Operation):
"""
Take two lists of operations - ones that will be used for the database,
and ones that will be used for the state change. This allows operations
that don't support state change to have it applied, or have operations
that affect the state or not the database, or so on.
"""
serialization_expand_args = ["database_operations", "state_operations"]
def __init__(self, database_operations=None, state_operations=None):
self.database_operations = database_operations or []
self.state_operations = state_operations or []
def deconstruct(self):
kwargs = {}
if self.database_operations:
kwargs["database_operations"] = self.database_operations
if self.state_operations:
kwargs["state_operations"] = self.state_operations
return (self.__class__.__qualname__, [], kwargs)
def state_forwards(self, app_label, state):
for state_operation in self.state_operations:
state_operation.state_forwards(app_label, state)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
# We calculate state separately in here since our state functions aren't useful
for database_operation in self.database_operations:
to_state = from_state.clone()
database_operation.state_forwards(app_label, to_state)
database_operation.database_forwards(
app_label, schema_editor, from_state, to_state
)
from_state = to_state
def database_backwards(self, app_label, schema_editor, from_state, to_state):
# We calculate state separately in here since our state functions aren't useful
to_states = {}
for dbop in self.database_operations:
to_states[dbop] = to_state
to_state = to_state.clone()
dbop.state_forwards(app_label, to_state)
# to_state now has the states of all the database_operations applied
# which is the from_state for the backwards migration of the last
# operation.
for database_operation in reversed(self.database_operations):
from_state = to_state
to_state = to_states[database_operation]
database_operation.database_backwards(
app_label, schema_editor, from_state, to_state
)
def describe(self):
return "Custom state/database change combination"
class RunSQL(Operation):
"""
Run some raw SQL. A reverse SQL statement may be provided.
Also accept a list of operations that represent the state change effected
by this SQL change, in case it's custom column/table creation/deletion.
"""
noop = ""
def __init__(
self, sql, reverse_sql=None, state_operations=None, hints=None, elidable=False
):
self.sql = sql
self.reverse_sql = reverse_sql
self.state_operations = state_operations or []
self.hints = hints or {}
self.elidable = elidable
def deconstruct(self):
kwargs = {
"sql": self.sql,
}
if self.reverse_sql is not None:
kwargs["reverse_sql"] = self.reverse_sql
if self.state_operations:
kwargs["state_operations"] = self.state_operations
if self.hints:
kwargs["hints"] = self.hints
return (self.__class__.__qualname__, [], kwargs)
@property
def reversible(self):
return self.reverse_sql is not None
def state_forwards(self, app_label, state):
for state_operation in self.state_operations:
state_operation.state_forwards(app_label, state)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
if router.allow_migrate(
schema_editor.connection.alias, app_label, **self.hints
):
self._run_sql(schema_editor, self.sql)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
if self.reverse_sql is None:
raise NotImplementedError("You cannot reverse this operation")
if router.allow_migrate(
schema_editor.connection.alias, app_label, **self.hints
):
self._run_sql(schema_editor, self.reverse_sql)
def describe(self):
return "Raw SQL operation"
def _run_sql(self, schema_editor, sqls):
if isinstance(sqls, (list, tuple)):
for sql in sqls:
params = None
if isinstance(sql, (list, tuple)):
elements = len(sql)
if elements == 2:
sql, params = sql
else:
raise ValueError("Expected a 2-tuple but got %d" % elements)
schema_editor.execute(sql, params=params)
elif sqls != RunSQL.noop:
statements = schema_editor.connection.ops.prepare_sql_script(sqls)
for statement in statements:
schema_editor.execute(statement, params=None)
class RunPython(Operation):
"""
Run Python code in a context suitable for doing versioned ORM operations.
"""
reduces_to_sql = False
def __init__(
self, code, reverse_code=None, atomic=None, hints=None, elidable=False
):
self.atomic = atomic
# Forwards code
if not callable(code):
raise ValueError("RunPython must be supplied with a callable")
self.code = code
# Reverse code
if reverse_code is None:
self.reverse_code = None
else:
if not callable(reverse_code):
raise ValueError("RunPython must be supplied with callable arguments")
self.reverse_code = reverse_code
self.hints = hints or {}
self.elidable = elidable
def deconstruct(self):
kwargs = {
"code": self.code,
}
if self.reverse_code is not None:
kwargs["reverse_code"] = self.reverse_code
if self.atomic is not None:
kwargs["atomic"] = self.atomic
if self.hints:
kwargs["hints"] = self.hints
return (self.__class__.__qualname__, [], kwargs)
@property
def reversible(self):
return self.reverse_code is not None
def state_forwards(self, app_label, state):
# RunPython objects have no state effect. To add some, combine this
# with SeparateDatabaseAndState.
pass
def database_forwards(self, app_label, schema_editor, from_state, to_state):
# RunPython has access to all models. Ensure that all models are
# reloaded in case any are delayed.
from_state.clear_delayed_apps_cache()
if router.allow_migrate(
schema_editor.connection.alias, app_label, **self.hints
):
# We now execute the Python code in a context that contains a 'models'
# object, representing the versioned models as an app registry.
# We could try to override the global cache, but then people will still
# use direct imports, so we go with a documentation approach instead.
self.code(from_state.apps, schema_editor)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
if self.reverse_code is None:
raise NotImplementedError("You cannot reverse this operation")
if router.allow_migrate(
schema_editor.connection.alias, app_label, **self.hints
):
self.reverse_code(from_state.apps, schema_editor)
def describe(self):
return "Raw Python operation"
@staticmethod
def noop(apps, schema_editor):
return None
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/operations/special.py
|
Python
|
mit
| 7,831 |
class MigrationOptimizer:
"""
Power the optimization process, where you provide a list of Operations
and you are returned a list of equal or shorter length - operations
are merged into one if possible.
For example, a CreateModel and an AddField can be optimized into a
new CreateModel, and CreateModel and DeleteModel can be optimized into
nothing.
"""
def optimize(self, operations, app_label):
"""
Main optimization entry point. Pass in a list of Operation instances,
get out a new list of Operation instances.
Unfortunately, due to the scope of the optimization (two combinable
operations might be separated by several hundred others), this can't be
done as a peephole optimization with checks/output implemented on
the Operations themselves; instead, the optimizer looks at each
individual operation and scans forwards in the list to see if there
are any matches, stopping at boundaries - operations which can't
be optimized over (RunSQL, operations on the same field/model, etc.)
The inner loop is run until the starting list is the same as the result
list, and then the result is returned. This means that operation
optimization must be stable and always return an equal or shorter list.
"""
# Internal tracking variable for test assertions about # of loops
if app_label is None:
raise TypeError("app_label must be a str.")
self._iterations = 0
while True:
result = self.optimize_inner(operations, app_label)
self._iterations += 1
if result == operations:
return result
operations = result
def optimize_inner(self, operations, app_label):
"""Inner optimization loop."""
new_operations = []
for i, operation in enumerate(operations):
right = True # Should we reduce on the right or on the left.
# Compare it to each operation after it
for j, other in enumerate(operations[i + 1 :]):
result = operation.reduce(other, app_label)
if isinstance(result, list):
in_between = operations[i + 1 : i + j + 1]
if right:
new_operations.extend(in_between)
new_operations.extend(result)
elif all(op.reduce(other, app_label) is True for op in in_between):
# Perform a left reduction if all of the in-between
# operations can optimize through other.
new_operations.extend(result)
new_operations.extend(in_between)
else:
# Otherwise keep trying.
new_operations.append(operation)
break
new_operations.extend(operations[i + j + 2 :])
return new_operations
elif not result:
# Can't perform a right reduction.
right = False
else:
new_operations.append(operation)
return new_operations
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/optimizer.py
|
Python
|
mit
| 3,255 |
import datetime
import importlib
import os
import sys
from django.apps import apps
from django.core.management.base import OutputWrapper
from django.db.models import NOT_PROVIDED
from django.utils import timezone
from django.utils.version import get_docs_version
from .loader import MigrationLoader
class MigrationQuestioner:
"""
Give the autodetector responses to questions it might have.
This base class has a built-in noninteractive mode, but the
interactive subclass is what the command-line arguments will use.
"""
def __init__(self, defaults=None, specified_apps=None, dry_run=None):
self.defaults = defaults or {}
self.specified_apps = specified_apps or set()
self.dry_run = dry_run
def ask_initial(self, app_label):
"""Should we create an initial migration for the app?"""
# If it was specified on the command line, definitely true
if app_label in self.specified_apps:
return True
# Otherwise, we look to see if it has a migrations module
# without any Python files in it, apart from __init__.py.
# Apps from the new app template will have these; the Python
# file check will ensure we skip South ones.
try:
app_config = apps.get_app_config(app_label)
except LookupError: # It's a fake app.
return self.defaults.get("ask_initial", False)
migrations_import_path, _ = MigrationLoader.migrations_module(app_config.label)
if migrations_import_path is None:
# It's an application with migrations disabled.
return self.defaults.get("ask_initial", False)
try:
migrations_module = importlib.import_module(migrations_import_path)
except ImportError:
return self.defaults.get("ask_initial", False)
else:
if getattr(migrations_module, "__file__", None):
filenames = os.listdir(os.path.dirname(migrations_module.__file__))
elif hasattr(migrations_module, "__path__"):
if len(migrations_module.__path__) > 1:
return False
filenames = os.listdir(list(migrations_module.__path__)[0])
return not any(x.endswith(".py") for x in filenames if x != "__init__.py")
def ask_not_null_addition(self, field_name, model_name):
"""Adding a NOT NULL field to a model."""
# None means quit
return None
def ask_not_null_alteration(self, field_name, model_name):
"""Changing a NULL field to NOT NULL."""
# None means quit
return None
def ask_rename(self, model_name, old_name, new_name, field_instance):
"""Was this field really renamed?"""
return self.defaults.get("ask_rename", False)
def ask_rename_model(self, old_model_state, new_model_state):
"""Was this model really renamed?"""
return self.defaults.get("ask_rename_model", False)
def ask_merge(self, app_label):
"""Should these migrations really be merged?"""
return self.defaults.get("ask_merge", False)
def ask_auto_now_add_addition(self, field_name, model_name):
"""Adding an auto_now_add field to a model."""
# None means quit
return None
def ask_unique_callable_default_addition(self, field_name, model_name):
"""Adding a unique field with a callable default."""
# None means continue.
return None
class InteractiveMigrationQuestioner(MigrationQuestioner):
def __init__(
self, defaults=None, specified_apps=None, dry_run=None, prompt_output=None
):
super().__init__(
defaults=defaults, specified_apps=specified_apps, dry_run=dry_run
)
self.prompt_output = prompt_output or OutputWrapper(sys.stdout)
def _boolean_input(self, question, default=None):
self.prompt_output.write(f"{question} ", ending="")
result = input()
if not result and default is not None:
return default
while not result or result[0].lower() not in "yn":
self.prompt_output.write("Please answer yes or no: ", ending="")
result = input()
return result[0].lower() == "y"
def _choice_input(self, question, choices):
self.prompt_output.write(f"{question}")
for i, choice in enumerate(choices):
self.prompt_output.write(" %s) %s" % (i + 1, choice))
self.prompt_output.write("Select an option: ", ending="")
result = input()
while True:
try:
value = int(result)
except ValueError:
pass
else:
if 0 < value <= len(choices):
return value
self.prompt_output.write("Please select a valid option: ", ending="")
result = input()
def _ask_default(self, default=""):
"""
Prompt for a default value.
The ``default`` argument allows providing a custom default value (as a
string) which will be shown to the user and used as the return value
if the user doesn't provide any other input.
"""
self.prompt_output.write("Please enter the default value as valid Python.")
if default:
self.prompt_output.write(
f"Accept the default '{default}' by pressing 'Enter' or "
f"provide another value."
)
self.prompt_output.write(
"The datetime and django.utils.timezone modules are available, so "
"it is possible to provide e.g. timezone.now as a value."
)
self.prompt_output.write("Type 'exit' to exit this prompt")
while True:
if default:
prompt = "[default: {}] >>> ".format(default)
else:
prompt = ">>> "
self.prompt_output.write(prompt, ending="")
code = input()
if not code and default:
code = default
if not code:
self.prompt_output.write(
"Please enter some code, or 'exit' (without quotes) to exit."
)
elif code == "exit":
sys.exit(1)
else:
try:
return eval(code, {}, {"datetime": datetime, "timezone": timezone})
except (SyntaxError, NameError) as e:
self.prompt_output.write("Invalid input: %s" % e)
def ask_not_null_addition(self, field_name, model_name):
"""Adding a NOT NULL field to a model."""
if not self.dry_run:
choice = self._choice_input(
f"It is impossible to add a non-nullable field '{field_name}' "
f"to {model_name} without specifying a default. This is "
f"because the database needs something to populate existing "
f"rows.\n"
f"Please select a fix:",
[
(
"Provide a one-off default now (will be set on all existing "
"rows with a null value for this column)"
),
"Quit and manually define a default value in models.py.",
],
)
if choice == 2:
sys.exit(3)
else:
return self._ask_default()
return None
def ask_not_null_alteration(self, field_name, model_name):
"""Changing a NULL field to NOT NULL."""
if not self.dry_run:
choice = self._choice_input(
f"It is impossible to change a nullable field '{field_name}' "
f"on {model_name} to non-nullable without providing a "
f"default. This is because the database needs something to "
f"populate existing rows.\n"
f"Please select a fix:",
[
(
"Provide a one-off default now (will be set on all existing "
"rows with a null value for this column)"
),
"Ignore for now. Existing rows that contain NULL values "
"will have to be handled manually, for example with a "
"RunPython or RunSQL operation.",
"Quit and manually define a default value in models.py.",
],
)
if choice == 2:
return NOT_PROVIDED
elif choice == 3:
sys.exit(3)
else:
return self._ask_default()
return None
def ask_rename(self, model_name, old_name, new_name, field_instance):
"""Was this field really renamed?"""
msg = "Was %s.%s renamed to %s.%s (a %s)? [y/N]"
return self._boolean_input(
msg
% (
model_name,
old_name,
model_name,
new_name,
field_instance.__class__.__name__,
),
False,
)
def ask_rename_model(self, old_model_state, new_model_state):
"""Was this model really renamed?"""
msg = "Was the model %s.%s renamed to %s? [y/N]"
return self._boolean_input(
msg
% (old_model_state.app_label, old_model_state.name, new_model_state.name),
False,
)
def ask_merge(self, app_label):
return self._boolean_input(
"\nMerging will only work if the operations printed above do not conflict\n"
+ "with each other (working on different fields or models)\n"
+ "Should these migration branches be merged? [y/N]",
False,
)
def ask_auto_now_add_addition(self, field_name, model_name):
"""Adding an auto_now_add field to a model."""
if not self.dry_run:
choice = self._choice_input(
f"It is impossible to add the field '{field_name}' with "
f"'auto_now_add=True' to {model_name} without providing a "
f"default. This is because the database needs something to "
f"populate existing rows.\n",
[
"Provide a one-off default now which will be set on all "
"existing rows",
"Quit and manually define a default value in models.py.",
],
)
if choice == 2:
sys.exit(3)
else:
return self._ask_default(default="timezone.now")
return None
def ask_unique_callable_default_addition(self, field_name, model_name):
"""Adding a unique field with a callable default."""
if not self.dry_run:
version = get_docs_version()
choice = self._choice_input(
f"Callable default on unique field {model_name}.{field_name} "
f"will not generate unique values upon migrating.\n"
f"Please choose how to proceed:\n",
[
f"Continue making this migration as the first step in "
f"writing a manual migration to generate unique values "
f"described here: "
f"https://docs.djangoproject.com/en/{version}/howto/"
f"writing-migrations/#migrations-that-add-unique-fields.",
"Quit and edit field options in models.py.",
],
)
if choice == 2:
sys.exit(3)
return None
class NonInteractiveMigrationQuestioner(MigrationQuestioner):
def __init__(
self,
defaults=None,
specified_apps=None,
dry_run=None,
verbosity=1,
log=None,
):
self.verbosity = verbosity
self.log = log
super().__init__(
defaults=defaults,
specified_apps=specified_apps,
dry_run=dry_run,
)
def log_lack_of_migration(self, field_name, model_name, reason):
if self.verbosity > 0:
self.log(
f"Field '{field_name}' on model '{model_name}' not migrated: "
f"{reason}."
)
def ask_not_null_addition(self, field_name, model_name):
# We can't ask the user, so act like the user aborted.
self.log_lack_of_migration(
field_name,
model_name,
"it is impossible to add a non-nullable field without specifying "
"a default",
)
sys.exit(3)
def ask_not_null_alteration(self, field_name, model_name):
# We can't ask the user, so set as not provided.
self.log(
f"Field '{field_name}' on model '{model_name}' given a default of "
f"NOT PROVIDED and must be corrected."
)
return NOT_PROVIDED
def ask_auto_now_add_addition(self, field_name, model_name):
# We can't ask the user, so act like the user aborted.
self.log_lack_of_migration(
field_name,
model_name,
"it is impossible to add a field with 'auto_now_add=True' without "
"specifying a default",
)
sys.exit(3)
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/questioner.py
|
Python
|
mit
| 13,330 |
from django.apps.registry import Apps
from django.db import DatabaseError, models
from django.utils.functional import classproperty
from django.utils.timezone import now
from .exceptions import MigrationSchemaMissing
class MigrationRecorder:
"""
Deal with storing migration records in the database.
Because this table is actually itself used for dealing with model
creation, it's the one thing we can't do normally via migrations.
We manually handle table creation/schema updating (using schema backend)
and then have a floating model to do queries with.
If a migration is unapplied its row is removed from the table. Having
a row in the table always means a migration is applied.
"""
_migration_class = None
@classproperty
def Migration(cls):
"""
Lazy load to avoid AppRegistryNotReady if installed apps import
MigrationRecorder.
"""
if cls._migration_class is None:
class Migration(models.Model):
app = models.CharField(max_length=255)
name = models.CharField(max_length=255)
applied = models.DateTimeField(default=now)
class Meta:
apps = Apps()
app_label = "migrations"
db_table = "django_migrations"
def __str__(self):
return "Migration %s for %s" % (self.name, self.app)
cls._migration_class = Migration
return cls._migration_class
def __init__(self, connection):
self.connection = connection
@property
def migration_qs(self):
return self.Migration.objects.using(self.connection.alias)
def has_table(self):
"""Return True if the django_migrations table exists."""
with self.connection.cursor() as cursor:
tables = self.connection.introspection.table_names(cursor)
return self.Migration._meta.db_table in tables
def ensure_schema(self):
"""Ensure the table exists and has the correct schema."""
# If the table's there, that's fine - we've never changed its schema
# in the codebase.
if self.has_table():
return
# Make the table
try:
with self.connection.schema_editor() as editor:
editor.create_model(self.Migration)
except DatabaseError as exc:
raise MigrationSchemaMissing(
"Unable to create the django_migrations table (%s)" % exc
)
def applied_migrations(self):
"""
Return a dict mapping (app_name, migration_name) to Migration instances
for all applied migrations.
"""
if self.has_table():
return {
(migration.app, migration.name): migration
for migration in self.migration_qs
}
else:
# If the django_migrations table doesn't exist, then no migrations
# are applied.
return {}
def record_applied(self, app, name):
"""Record that a migration was applied."""
self.ensure_schema()
self.migration_qs.create(app=app, name=name)
def record_unapplied(self, app, name):
"""Record that a migration was unapplied."""
self.ensure_schema()
self.migration_qs.filter(app=app, name=name).delete()
def flush(self):
"""Delete all migration records. Useful for testing migrations."""
self.migration_qs.all().delete()
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/recorder.py
|
Python
|
mit
| 3,535 |
import builtins
import collections.abc
import datetime
import decimal
import enum
import functools
import math
import os
import pathlib
import re
import types
import uuid
from django.conf import SettingsReference
from django.db import models
from django.db.migrations.operations.base import Operation
from django.db.migrations.utils import COMPILED_REGEX_TYPE, RegexObject
from django.utils.functional import LazyObject, Promise
from django.utils.version import PY311, get_docs_version
class BaseSerializer:
def __init__(self, value):
self.value = value
def serialize(self):
raise NotImplementedError(
"Subclasses of BaseSerializer must implement the serialize() method."
)
class BaseSequenceSerializer(BaseSerializer):
def _format(self):
raise NotImplementedError(
"Subclasses of BaseSequenceSerializer must implement the _format() method."
)
def serialize(self):
imports = set()
strings = []
for item in self.value:
item_string, item_imports = serializer_factory(item).serialize()
imports.update(item_imports)
strings.append(item_string)
value = self._format()
return value % (", ".join(strings)), imports
class BaseSimpleSerializer(BaseSerializer):
def serialize(self):
return repr(self.value), set()
class ChoicesSerializer(BaseSerializer):
def serialize(self):
return serializer_factory(self.value.value).serialize()
class DateTimeSerializer(BaseSerializer):
"""For datetime.*, except datetime.datetime."""
def serialize(self):
return repr(self.value), {"import datetime"}
class DatetimeDatetimeSerializer(BaseSerializer):
"""For datetime.datetime."""
def serialize(self):
if self.value.tzinfo is not None and self.value.tzinfo != datetime.timezone.utc:
self.value = self.value.astimezone(datetime.timezone.utc)
imports = ["import datetime"]
return repr(self.value), set(imports)
class DecimalSerializer(BaseSerializer):
def serialize(self):
return repr(self.value), {"from decimal import Decimal"}
class DeconstructableSerializer(BaseSerializer):
@staticmethod
def serialize_deconstructed(path, args, kwargs):
name, imports = DeconstructableSerializer._serialize_path(path)
strings = []
for arg in args:
arg_string, arg_imports = serializer_factory(arg).serialize()
strings.append(arg_string)
imports.update(arg_imports)
for kw, arg in sorted(kwargs.items()):
arg_string, arg_imports = serializer_factory(arg).serialize()
imports.update(arg_imports)
strings.append("%s=%s" % (kw, arg_string))
return "%s(%s)" % (name, ", ".join(strings)), imports
@staticmethod
def _serialize_path(path):
module, name = path.rsplit(".", 1)
if module == "django.db.models":
imports = {"from django.db import models"}
name = "models.%s" % name
else:
imports = {"import %s" % module}
name = path
return name, imports
def serialize(self):
return self.serialize_deconstructed(*self.value.deconstruct())
class DictionarySerializer(BaseSerializer):
def serialize(self):
imports = set()
strings = []
for k, v in sorted(self.value.items()):
k_string, k_imports = serializer_factory(k).serialize()
v_string, v_imports = serializer_factory(v).serialize()
imports.update(k_imports)
imports.update(v_imports)
strings.append((k_string, v_string))
return "{%s}" % (", ".join("%s: %s" % (k, v) for k, v in strings)), imports
class EnumSerializer(BaseSerializer):
def serialize(self):
enum_class = self.value.__class__
module = enum_class.__module__
if issubclass(enum_class, enum.Flag):
if PY311:
members = list(self.value)
else:
members, _ = enum._decompose(enum_class, self.value)
members = reversed(members)
else:
members = (self.value,)
return (
" | ".join(
[
f"{module}.{enum_class.__qualname__}[{item.name!r}]"
for item in members
]
),
{"import %s" % module},
)
class FloatSerializer(BaseSimpleSerializer):
def serialize(self):
if math.isnan(self.value) or math.isinf(self.value):
return 'float("{}")'.format(self.value), set()
return super().serialize()
class FrozensetSerializer(BaseSequenceSerializer):
def _format(self):
return "frozenset([%s])"
class FunctionTypeSerializer(BaseSerializer):
def serialize(self):
if getattr(self.value, "__self__", None) and isinstance(
self.value.__self__, type
):
klass = self.value.__self__
module = klass.__module__
return "%s.%s.%s" % (module, klass.__name__, self.value.__name__), {
"import %s" % module
}
# Further error checking
if self.value.__name__ == "<lambda>":
raise ValueError("Cannot serialize function: lambda")
if self.value.__module__ is None:
raise ValueError("Cannot serialize function %r: No module" % self.value)
module_name = self.value.__module__
if "<" not in self.value.__qualname__: # Qualname can include <locals>
return "%s.%s" % (module_name, self.value.__qualname__), {
"import %s" % self.value.__module__
}
raise ValueError(
"Could not find function %s in %s.\n" % (self.value.__name__, module_name)
)
class FunctoolsPartialSerializer(BaseSerializer):
def serialize(self):
# Serialize functools.partial() arguments
func_string, func_imports = serializer_factory(self.value.func).serialize()
args_string, args_imports = serializer_factory(self.value.args).serialize()
keywords_string, keywords_imports = serializer_factory(
self.value.keywords
).serialize()
# Add any imports needed by arguments
imports = {"import functools", *func_imports, *args_imports, *keywords_imports}
return (
"functools.%s(%s, *%s, **%s)"
% (
self.value.__class__.__name__,
func_string,
args_string,
keywords_string,
),
imports,
)
class IterableSerializer(BaseSerializer):
def serialize(self):
imports = set()
strings = []
for item in self.value:
item_string, item_imports = serializer_factory(item).serialize()
imports.update(item_imports)
strings.append(item_string)
# When len(strings)==0, the empty iterable should be serialized as
# "()", not "(,)" because (,) is invalid Python syntax.
value = "(%s)" if len(strings) != 1 else "(%s,)"
return value % (", ".join(strings)), imports
class ModelFieldSerializer(DeconstructableSerializer):
def serialize(self):
attr_name, path, args, kwargs = self.value.deconstruct()
return self.serialize_deconstructed(path, args, kwargs)
class ModelManagerSerializer(DeconstructableSerializer):
def serialize(self):
as_manager, manager_path, qs_path, args, kwargs = self.value.deconstruct()
if as_manager:
name, imports = self._serialize_path(qs_path)
return "%s.as_manager()" % name, imports
else:
return self.serialize_deconstructed(manager_path, args, kwargs)
class OperationSerializer(BaseSerializer):
def serialize(self):
from django.db.migrations.writer import OperationWriter
string, imports = OperationWriter(self.value, indentation=0).serialize()
# Nested operation, trailing comma is handled in upper OperationWriter._write()
return string.rstrip(","), imports
class PathLikeSerializer(BaseSerializer):
def serialize(self):
return repr(os.fspath(self.value)), {}
class PathSerializer(BaseSerializer):
def serialize(self):
# Convert concrete paths to pure paths to avoid issues with migrations
# generated on one platform being used on a different platform.
prefix = "Pure" if isinstance(self.value, pathlib.Path) else ""
return "pathlib.%s%r" % (prefix, self.value), {"import pathlib"}
class RegexSerializer(BaseSerializer):
def serialize(self):
regex_pattern, pattern_imports = serializer_factory(
self.value.pattern
).serialize()
# Turn off default implicit flags (e.g. re.U) because regexes with the
# same implicit and explicit flags aren't equal.
flags = self.value.flags ^ re.compile("").flags
regex_flags, flag_imports = serializer_factory(flags).serialize()
imports = {"import re", *pattern_imports, *flag_imports}
args = [regex_pattern]
if flags:
args.append(regex_flags)
return "re.compile(%s)" % ", ".join(args), imports
class SequenceSerializer(BaseSequenceSerializer):
def _format(self):
return "[%s]"
class SetSerializer(BaseSequenceSerializer):
def _format(self):
# Serialize as a set literal except when value is empty because {}
# is an empty dict.
return "{%s}" if self.value else "set(%s)"
class SettingsReferenceSerializer(BaseSerializer):
def serialize(self):
return "settings.%s" % self.value.setting_name, {
"from django.conf import settings"
}
class TupleSerializer(BaseSequenceSerializer):
def _format(self):
# When len(value)==0, the empty tuple should be serialized as "()",
# not "(,)" because (,) is invalid Python syntax.
return "(%s)" if len(self.value) != 1 else "(%s,)"
class TypeSerializer(BaseSerializer):
def serialize(self):
special_cases = [
(models.Model, "models.Model", ["from django.db import models"]),
(type(None), "type(None)", []),
]
for case, string, imports in special_cases:
if case is self.value:
return string, set(imports)
if hasattr(self.value, "__module__"):
module = self.value.__module__
if module == builtins.__name__:
return self.value.__name__, set()
else:
return "%s.%s" % (module, self.value.__qualname__), {
"import %s" % module
}
class UUIDSerializer(BaseSerializer):
def serialize(self):
return "uuid.%s" % repr(self.value), {"import uuid"}
class Serializer:
_registry = {
# Some of these are order-dependent.
frozenset: FrozensetSerializer,
list: SequenceSerializer,
set: SetSerializer,
tuple: TupleSerializer,
dict: DictionarySerializer,
models.Choices: ChoicesSerializer,
enum.Enum: EnumSerializer,
datetime.datetime: DatetimeDatetimeSerializer,
(datetime.date, datetime.timedelta, datetime.time): DateTimeSerializer,
SettingsReference: SettingsReferenceSerializer,
float: FloatSerializer,
(bool, int, type(None), bytes, str, range): BaseSimpleSerializer,
decimal.Decimal: DecimalSerializer,
(functools.partial, functools.partialmethod): FunctoolsPartialSerializer,
(
types.FunctionType,
types.BuiltinFunctionType,
types.MethodType,
): FunctionTypeSerializer,
collections.abc.Iterable: IterableSerializer,
(COMPILED_REGEX_TYPE, RegexObject): RegexSerializer,
uuid.UUID: UUIDSerializer,
pathlib.PurePath: PathSerializer,
os.PathLike: PathLikeSerializer,
}
@classmethod
def register(cls, type_, serializer):
if not issubclass(serializer, BaseSerializer):
raise ValueError(
"'%s' must inherit from 'BaseSerializer'." % serializer.__name__
)
cls._registry[type_] = serializer
@classmethod
def unregister(cls, type_):
cls._registry.pop(type_)
def serializer_factory(value):
if isinstance(value, Promise):
value = str(value)
elif isinstance(value, LazyObject):
# The unwrapped value is returned as the first item of the arguments
# tuple.
value = value.__reduce__()[1][0]
if isinstance(value, models.Field):
return ModelFieldSerializer(value)
if isinstance(value, models.manager.BaseManager):
return ModelManagerSerializer(value)
if isinstance(value, Operation):
return OperationSerializer(value)
if isinstance(value, type):
return TypeSerializer(value)
# Anything that knows how to deconstruct itself.
if hasattr(value, "deconstruct"):
return DeconstructableSerializer(value)
for type_, serializer_cls in Serializer._registry.items():
if isinstance(value, type_):
return serializer_cls(value)
raise ValueError(
"Cannot serialize: %r\nThere are some values Django cannot serialize into "
"migration files.\nFor more, see https://docs.djangoproject.com/en/%s/"
"topics/migrations/#migration-serializing" % (value, get_docs_version())
)
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/serializer.py
|
Python
|
mit
| 13,560 |
import copy
from collections import defaultdict
from contextlib import contextmanager
from functools import partial
from django.apps import AppConfig
from django.apps.registry import Apps
from django.apps.registry import apps as global_apps
from django.conf import settings
from django.core.exceptions import FieldDoesNotExist
from django.db import models
from django.db.migrations.utils import field_is_referenced, get_references
from django.db.models import NOT_PROVIDED
from django.db.models.fields.related import RECURSIVE_RELATIONSHIP_CONSTANT
from django.db.models.options import DEFAULT_NAMES, normalize_together
from django.db.models.utils import make_model_tuple
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from django.utils.version import get_docs_version
from .exceptions import InvalidBasesError
from .utils import resolve_relation
def _get_app_label_and_model_name(model, app_label=""):
if isinstance(model, str):
split = model.split(".", 1)
return tuple(split) if len(split) == 2 else (app_label, split[0])
else:
return model._meta.app_label, model._meta.model_name
def _get_related_models(m):
"""Return all models that have a direct relationship to the given model."""
related_models = [
subclass
for subclass in m.__subclasses__()
if issubclass(subclass, models.Model)
]
related_fields_models = set()
for f in m._meta.get_fields(include_parents=True, include_hidden=True):
if (
f.is_relation
and f.related_model is not None
and not isinstance(f.related_model, str)
):
related_fields_models.add(f.model)
related_models.append(f.related_model)
# Reverse accessors of foreign keys to proxy models are attached to their
# concrete proxied model.
opts = m._meta
if opts.proxy and m in related_fields_models:
related_models.append(opts.concrete_model)
return related_models
def get_related_models_tuples(model):
"""
Return a list of typical (app_label, model_name) tuples for all related
models for the given model.
"""
return {
(rel_mod._meta.app_label, rel_mod._meta.model_name)
for rel_mod in _get_related_models(model)
}
def get_related_models_recursive(model):
"""
Return all models that have a direct or indirect relationship
to the given model.
Relationships are either defined by explicit relational fields, like
ForeignKey, ManyToManyField or OneToOneField, or by inheriting from another
model (a superclass is related to its subclasses, but not vice versa). Note,
however, that a model inheriting from a concrete model is also related to
its superclass through the implicit *_ptr OneToOneField on the subclass.
"""
seen = set()
queue = _get_related_models(model)
for rel_mod in queue:
rel_app_label, rel_model_name = (
rel_mod._meta.app_label,
rel_mod._meta.model_name,
)
if (rel_app_label, rel_model_name) in seen:
continue
seen.add((rel_app_label, rel_model_name))
queue.extend(_get_related_models(rel_mod))
return seen - {(model._meta.app_label, model._meta.model_name)}
class ProjectState:
"""
Represent the entire project's overall state. This is the item that is
passed around - do it here rather than at the app level so that cross-app
FKs/etc. resolve properly.
"""
def __init__(self, models=None, real_apps=None):
self.models = models or {}
# Apps to include from main registry, usually unmigrated ones
if real_apps is None:
real_apps = set()
else:
assert isinstance(real_apps, set)
self.real_apps = real_apps
self.is_delayed = False
# {remote_model_key: {model_key: {field_name: field}}}
self._relations = None
@property
def relations(self):
if self._relations is None:
self.resolve_fields_and_relations()
return self._relations
def add_model(self, model_state):
model_key = model_state.app_label, model_state.name_lower
self.models[model_key] = model_state
if self._relations is not None:
self.resolve_model_relations(model_key)
if "apps" in self.__dict__: # hasattr would cache the property
self.reload_model(*model_key)
def remove_model(self, app_label, model_name):
model_key = app_label, model_name
del self.models[model_key]
if self._relations is not None:
self._relations.pop(model_key, None)
# Call list() since _relations can change size during iteration.
for related_model_key, model_relations in list(self._relations.items()):
model_relations.pop(model_key, None)
if not model_relations:
del self._relations[related_model_key]
if "apps" in self.__dict__: # hasattr would cache the property
self.apps.unregister_model(*model_key)
# Need to do this explicitly since unregister_model() doesn't clear
# the cache automatically (#24513)
self.apps.clear_cache()
def rename_model(self, app_label, old_name, new_name):
# Add a new model.
old_name_lower = old_name.lower()
new_name_lower = new_name.lower()
renamed_model = self.models[app_label, old_name_lower].clone()
renamed_model.name = new_name
self.models[app_label, new_name_lower] = renamed_model
# Repoint all fields pointing to the old model to the new one.
old_model_tuple = (app_label, old_name_lower)
new_remote_model = f"{app_label}.{new_name}"
to_reload = set()
for model_state, name, field, reference in get_references(
self, old_model_tuple
):
changed_field = None
if reference.to:
changed_field = field.clone()
changed_field.remote_field.model = new_remote_model
if reference.through:
if changed_field is None:
changed_field = field.clone()
changed_field.remote_field.through = new_remote_model
if changed_field:
model_state.fields[name] = changed_field
to_reload.add((model_state.app_label, model_state.name_lower))
if self._relations is not None:
old_name_key = app_label, old_name_lower
new_name_key = app_label, new_name_lower
if old_name_key in self._relations:
self._relations[new_name_key] = self._relations.pop(old_name_key)
for model_relations in self._relations.values():
if old_name_key in model_relations:
model_relations[new_name_key] = model_relations.pop(old_name_key)
# Reload models related to old model before removing the old model.
self.reload_models(to_reload, delay=True)
# Remove the old model.
self.remove_model(app_label, old_name_lower)
self.reload_model(app_label, new_name_lower, delay=True)
def alter_model_options(self, app_label, model_name, options, option_keys=None):
model_state = self.models[app_label, model_name]
model_state.options = {**model_state.options, **options}
if option_keys:
for key in option_keys:
if key not in options:
model_state.options.pop(key, False)
self.reload_model(app_label, model_name, delay=True)
def remove_model_options(self, app_label, model_name, option_name, value_to_remove):
model_state = self.models[app_label, model_name]
if objs := model_state.options.get(option_name):
model_state.options[option_name] = [
obj for obj in objs if tuple(obj) != tuple(value_to_remove)
]
self.reload_model(app_label, model_name, delay=True)
def alter_model_managers(self, app_label, model_name, managers):
model_state = self.models[app_label, model_name]
model_state.managers = list(managers)
self.reload_model(app_label, model_name, delay=True)
def _append_option(self, app_label, model_name, option_name, obj):
model_state = self.models[app_label, model_name]
model_state.options[option_name] = [*model_state.options[option_name], obj]
self.reload_model(app_label, model_name, delay=True)
def _remove_option(self, app_label, model_name, option_name, obj_name):
model_state = self.models[app_label, model_name]
objs = model_state.options[option_name]
model_state.options[option_name] = [obj for obj in objs if obj.name != obj_name]
self.reload_model(app_label, model_name, delay=True)
def add_index(self, app_label, model_name, index):
self._append_option(app_label, model_name, "indexes", index)
def remove_index(self, app_label, model_name, index_name):
self._remove_option(app_label, model_name, "indexes", index_name)
def rename_index(self, app_label, model_name, old_index_name, new_index_name):
model_state = self.models[app_label, model_name]
objs = model_state.options["indexes"]
new_indexes = []
for obj in objs:
if obj.name == old_index_name:
obj = obj.clone()
obj.name = new_index_name
new_indexes.append(obj)
model_state.options["indexes"] = new_indexes
self.reload_model(app_label, model_name, delay=True)
def add_constraint(self, app_label, model_name, constraint):
self._append_option(app_label, model_name, "constraints", constraint)
def remove_constraint(self, app_label, model_name, constraint_name):
self._remove_option(app_label, model_name, "constraints", constraint_name)
def add_field(self, app_label, model_name, name, field, preserve_default):
# If preserve default is off, don't use the default for future state.
if not preserve_default:
field = field.clone()
field.default = NOT_PROVIDED
else:
field = field
model_key = app_label, model_name
self.models[model_key].fields[name] = field
if self._relations is not None:
self.resolve_model_field_relations(model_key, name, field)
# Delay rendering of relationships if it's not a relational field.
delay = not field.is_relation
self.reload_model(*model_key, delay=delay)
def remove_field(self, app_label, model_name, name):
model_key = app_label, model_name
model_state = self.models[model_key]
old_field = model_state.fields.pop(name)
if self._relations is not None:
self.resolve_model_field_relations(model_key, name, old_field)
# Delay rendering of relationships if it's not a relational field.
delay = not old_field.is_relation
self.reload_model(*model_key, delay=delay)
def alter_field(self, app_label, model_name, name, field, preserve_default):
if not preserve_default:
field = field.clone()
field.default = NOT_PROVIDED
else:
field = field
model_key = app_label, model_name
fields = self.models[model_key].fields
if self._relations is not None:
old_field = fields.pop(name)
if old_field.is_relation:
self.resolve_model_field_relations(model_key, name, old_field)
fields[name] = field
if field.is_relation:
self.resolve_model_field_relations(model_key, name, field)
else:
fields[name] = field
# TODO: investigate if old relational fields must be reloaded or if
# it's sufficient if the new field is (#27737).
# Delay rendering of relationships if it's not a relational field and
# not referenced by a foreign key.
delay = not field.is_relation and not field_is_referenced(
self, model_key, (name, field)
)
self.reload_model(*model_key, delay=delay)
def rename_field(self, app_label, model_name, old_name, new_name):
model_key = app_label, model_name
model_state = self.models[model_key]
# Rename the field.
fields = model_state.fields
try:
found = fields.pop(old_name)
except KeyError:
raise FieldDoesNotExist(
f"{app_label}.{model_name} has no field named '{old_name}'"
)
fields[new_name] = found
for field in fields.values():
# Fix from_fields to refer to the new field.
from_fields = getattr(field, "from_fields", None)
if from_fields:
field.from_fields = tuple(
[
new_name if from_field_name == old_name else from_field_name
for from_field_name in from_fields
]
)
# Fix index/unique_together to refer to the new field.
options = model_state.options
for option in ("index_together", "unique_together"):
if option in options:
options[option] = [
[new_name if n == old_name else n for n in together]
for together in options[option]
]
# Fix to_fields to refer to the new field.
delay = True
references = get_references(self, model_key, (old_name, found))
for *_, field, reference in references:
delay = False
if reference.to:
remote_field, to_fields = reference.to
if getattr(remote_field, "field_name", None) == old_name:
remote_field.field_name = new_name
if to_fields:
field.to_fields = tuple(
[
new_name if to_field_name == old_name else to_field_name
for to_field_name in to_fields
]
)
if self._relations is not None:
old_name_lower = old_name.lower()
new_name_lower = new_name.lower()
for to_model in self._relations.values():
if old_name_lower in to_model[model_key]:
field = to_model[model_key].pop(old_name_lower)
field.name = new_name_lower
to_model[model_key][new_name_lower] = field
self.reload_model(*model_key, delay=delay)
def _find_reload_model(self, app_label, model_name, delay=False):
if delay:
self.is_delayed = True
related_models = set()
try:
old_model = self.apps.get_model(app_label, model_name)
except LookupError:
pass
else:
# Get all relations to and from the old model before reloading,
# as _meta.apps may change
if delay:
related_models = get_related_models_tuples(old_model)
else:
related_models = get_related_models_recursive(old_model)
# Get all outgoing references from the model to be rendered
model_state = self.models[(app_label, model_name)]
# Directly related models are the models pointed to by ForeignKeys,
# OneToOneFields, and ManyToManyFields.
direct_related_models = set()
for field in model_state.fields.values():
if field.is_relation:
if field.remote_field.model == RECURSIVE_RELATIONSHIP_CONSTANT:
continue
rel_app_label, rel_model_name = _get_app_label_and_model_name(
field.related_model, app_label
)
direct_related_models.add((rel_app_label, rel_model_name.lower()))
# For all direct related models recursively get all related models.
related_models.update(direct_related_models)
for rel_app_label, rel_model_name in direct_related_models:
try:
rel_model = self.apps.get_model(rel_app_label, rel_model_name)
except LookupError:
pass
else:
if delay:
related_models.update(get_related_models_tuples(rel_model))
else:
related_models.update(get_related_models_recursive(rel_model))
# Include the model itself
related_models.add((app_label, model_name))
return related_models
def reload_model(self, app_label, model_name, delay=False):
if "apps" in self.__dict__: # hasattr would cache the property
related_models = self._find_reload_model(app_label, model_name, delay)
self._reload(related_models)
def reload_models(self, models, delay=True):
if "apps" in self.__dict__: # hasattr would cache the property
related_models = set()
for app_label, model_name in models:
related_models.update(
self._find_reload_model(app_label, model_name, delay)
)
self._reload(related_models)
def _reload(self, related_models):
# Unregister all related models
with self.apps.bulk_update():
for rel_app_label, rel_model_name in related_models:
self.apps.unregister_model(rel_app_label, rel_model_name)
states_to_be_rendered = []
# Gather all models states of those models that will be rerendered.
# This includes:
# 1. All related models of unmigrated apps
for model_state in self.apps.real_models:
if (model_state.app_label, model_state.name_lower) in related_models:
states_to_be_rendered.append(model_state)
# 2. All related models of migrated apps
for rel_app_label, rel_model_name in related_models:
try:
model_state = self.models[rel_app_label, rel_model_name]
except KeyError:
pass
else:
states_to_be_rendered.append(model_state)
# Render all models
self.apps.render_multiple(states_to_be_rendered)
def update_model_field_relation(
self,
model,
model_key,
field_name,
field,
concretes,
):
remote_model_key = resolve_relation(model, *model_key)
if remote_model_key[0] not in self.real_apps and remote_model_key in concretes:
remote_model_key = concretes[remote_model_key]
relations_to_remote_model = self._relations[remote_model_key]
if field_name in self.models[model_key].fields:
# The assert holds because it's a new relation, or an altered
# relation, in which case references have been removed by
# alter_field().
assert field_name not in relations_to_remote_model[model_key]
relations_to_remote_model[model_key][field_name] = field
else:
del relations_to_remote_model[model_key][field_name]
if not relations_to_remote_model[model_key]:
del relations_to_remote_model[model_key]
def resolve_model_field_relations(
self,
model_key,
field_name,
field,
concretes=None,
):
remote_field = field.remote_field
if not remote_field:
return
if concretes is None:
concretes, _ = self._get_concrete_models_mapping_and_proxy_models()
self.update_model_field_relation(
remote_field.model,
model_key,
field_name,
field,
concretes,
)
through = getattr(remote_field, "through", None)
if not through:
return
self.update_model_field_relation(
through, model_key, field_name, field, concretes
)
def resolve_model_relations(self, model_key, concretes=None):
if concretes is None:
concretes, _ = self._get_concrete_models_mapping_and_proxy_models()
model_state = self.models[model_key]
for field_name, field in model_state.fields.items():
self.resolve_model_field_relations(model_key, field_name, field, concretes)
def resolve_fields_and_relations(self):
# Resolve fields.
for model_state in self.models.values():
for field_name, field in model_state.fields.items():
field.name = field_name
# Resolve relations.
# {remote_model_key: {model_key: {field_name: field}}}
self._relations = defaultdict(partial(defaultdict, dict))
concretes, proxies = self._get_concrete_models_mapping_and_proxy_models()
for model_key in concretes:
self.resolve_model_relations(model_key, concretes)
for model_key in proxies:
self._relations[model_key] = self._relations[concretes[model_key]]
def get_concrete_model_key(self, model):
(
concrete_models_mapping,
_,
) = self._get_concrete_models_mapping_and_proxy_models()
model_key = make_model_tuple(model)
return concrete_models_mapping[model_key]
def _get_concrete_models_mapping_and_proxy_models(self):
concrete_models_mapping = {}
proxy_models = {}
# Split models to proxy and concrete models.
for model_key, model_state in self.models.items():
if model_state.options.get("proxy"):
proxy_models[model_key] = model_state
# Find a concrete model for the proxy.
concrete_models_mapping[
model_key
] = self._find_concrete_model_from_proxy(
proxy_models,
model_state,
)
else:
concrete_models_mapping[model_key] = model_key
return concrete_models_mapping, proxy_models
def _find_concrete_model_from_proxy(self, proxy_models, model_state):
for base in model_state.bases:
if not (isinstance(base, str) or issubclass(base, models.Model)):
continue
base_key = make_model_tuple(base)
base_state = proxy_models.get(base_key)
if not base_state:
# Concrete model found, stop looking at bases.
return base_key
return self._find_concrete_model_from_proxy(proxy_models, base_state)
def clone(self):
"""Return an exact copy of this ProjectState."""
new_state = ProjectState(
models={k: v.clone() for k, v in self.models.items()},
real_apps=self.real_apps,
)
if "apps" in self.__dict__:
new_state.apps = self.apps.clone()
new_state.is_delayed = self.is_delayed
return new_state
def clear_delayed_apps_cache(self):
if self.is_delayed and "apps" in self.__dict__:
del self.__dict__["apps"]
@cached_property
def apps(self):
return StateApps(self.real_apps, self.models)
@classmethod
def from_apps(cls, apps):
"""Take an Apps and return a ProjectState matching it."""
app_models = {}
for model in apps.get_models(include_swapped=True):
model_state = ModelState.from_model(model)
app_models[(model_state.app_label, model_state.name_lower)] = model_state
return cls(app_models)
def __eq__(self, other):
return self.models == other.models and self.real_apps == other.real_apps
class AppConfigStub(AppConfig):
"""Stub of an AppConfig. Only provides a label and a dict of models."""
def __init__(self, label):
self.apps = None
self.models = {}
# App-label and app-name are not the same thing, so technically passing
# in the label here is wrong. In practice, migrations don't care about
# the app name, but we need something unique, and the label works fine.
self.label = label
self.name = label
def import_models(self):
self.models = self.apps.all_models[self.label]
class StateApps(Apps):
"""
Subclass of the global Apps registry class to better handle dynamic model
additions and removals.
"""
def __init__(self, real_apps, models, ignore_swappable=False):
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
# FKs/M2Ms from real apps are also not included as they just
# mess things up with partial states (due to lack of dependencies)
self.real_models = []
for app_label in real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
self.real_models.append(ModelState.from_model(model, exclude_rels=True))
# Populate the app registry with a stub for each application.
app_labels = {model_state.app_label for model_state in models.values()}
app_configs = [
AppConfigStub(label) for label in sorted([*real_apps, *app_labels])
]
super().__init__(app_configs)
# These locks get in the way of copying as implemented in clone(),
# which is called whenever Django duplicates a StateApps before
# updating it.
self._lock = None
self.ready_event = None
self.render_multiple([*models.values(), *self.real_models])
# There shouldn't be any operations pending at this point.
from django.core.checks.model_checks import _check_lazy_references
ignore = (
{make_model_tuple(settings.AUTH_USER_MODEL)} if ignore_swappable else set()
)
errors = _check_lazy_references(self, ignore=ignore)
if errors:
raise ValueError("\n".join(error.msg for error in errors))
@contextmanager
def bulk_update(self):
# Avoid clearing each model's cache for each change. Instead, clear
# all caches when we're finished updating the model instances.
ready = self.ready
self.ready = False
try:
yield
finally:
self.ready = ready
self.clear_cache()
def render_multiple(self, model_states):
# We keep trying to render the models in a loop, ignoring invalid
# base errors, until the size of the unrendered models doesn't
# decrease by at least one, meaning there's a base dependency loop/
# missing base.
if not model_states:
return
# Prevent that all model caches are expired for each render.
with self.bulk_update():
unrendered_models = model_states
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self)
except InvalidBasesError:
new_unrendered_models.append(model)
if len(new_unrendered_models) == len(unrendered_models):
raise InvalidBasesError(
"Cannot resolve bases for %r\nThis can happen if you are "
"inheriting models from an app with migrations (e.g. "
"contrib.auth)\n in an app with no migrations; see "
"https://docs.djangoproject.com/en/%s/topics/migrations/"
"#dependencies for more"
% (new_unrendered_models, get_docs_version())
)
unrendered_models = new_unrendered_models
def clone(self):
"""Return a clone of this registry."""
clone = StateApps([], {})
clone.all_models = copy.deepcopy(self.all_models)
for app_label in self.app_configs:
app_config = AppConfigStub(app_label)
app_config.apps = clone
app_config.import_models()
clone.app_configs[app_label] = app_config
# No need to actually clone them, they'll never change
clone.real_models = self.real_models
return clone
def register_model(self, app_label, model):
self.all_models[app_label][model._meta.model_name] = model
if app_label not in self.app_configs:
self.app_configs[app_label] = AppConfigStub(app_label)
self.app_configs[app_label].apps = self
self.app_configs[app_label].models[model._meta.model_name] = model
self.do_pending_operations(model)
self.clear_cache()
def unregister_model(self, app_label, model_name):
try:
del self.all_models[app_label][model_name]
del self.app_configs[app_label].models[model_name]
except KeyError:
pass
class ModelState:
"""
Represent a Django Model. Don't use the actual Model class as it's not
designed to have its options changed - instead, mutate this one and then
render it into a Model as required.
Note that while you are allowed to mutate .fields, you are not allowed
to mutate the Field instances inside there themselves - you must instead
assign new ones, as these are not detached during a clone.
"""
def __init__(
self, app_label, name, fields, options=None, bases=None, managers=None
):
self.app_label = app_label
self.name = name
self.fields = dict(fields)
self.options = options or {}
self.options.setdefault("indexes", [])
self.options.setdefault("constraints", [])
self.bases = bases or (models.Model,)
self.managers = managers or []
for name, field in self.fields.items():
# Sanity-check that fields are NOT already bound to a model.
if hasattr(field, "model"):
raise ValueError(
'ModelState.fields cannot be bound to a model - "%s" is.' % name
)
# Sanity-check that relation fields are NOT referring to a model class.
if field.is_relation and hasattr(field.related_model, "_meta"):
raise ValueError(
'ModelState.fields cannot refer to a model class - "%s.to" does. '
"Use a string reference instead." % name
)
if field.many_to_many and hasattr(field.remote_field.through, "_meta"):
raise ValueError(
'ModelState.fields cannot refer to a model class - "%s.through" '
"does. Use a string reference instead." % name
)
# Sanity-check that indexes have their name set.
for index in self.options["indexes"]:
if not index.name:
raise ValueError(
"Indexes passed to ModelState require a name attribute. "
"%r doesn't have one." % index
)
@cached_property
def name_lower(self):
return self.name.lower()
def get_field(self, field_name):
if field_name == "_order":
field_name = self.options.get("order_with_respect_to", field_name)
return self.fields[field_name]
@classmethod
def from_model(cls, model, exclude_rels=False):
"""Given a model, return a ModelState representing it."""
# Deconstruct the fields
fields = []
for field in model._meta.local_fields:
if getattr(field, "remote_field", None) and exclude_rels:
continue
if isinstance(field, models.OrderWrt):
continue
name = field.name
try:
fields.append((name, field.clone()))
except TypeError as e:
raise TypeError(
"Couldn't reconstruct field %s on %s: %s"
% (
name,
model._meta.label,
e,
)
)
if not exclude_rels:
for field in model._meta.local_many_to_many:
name = field.name
try:
fields.append((name, field.clone()))
except TypeError as e:
raise TypeError(
"Couldn't reconstruct m2m field %s on %s: %s"
% (
name,
model._meta.object_name,
e,
)
)
# Extract the options
options = {}
for name in DEFAULT_NAMES:
# Ignore some special options
if name in ["apps", "app_label"]:
continue
elif name in model._meta.original_attrs:
if name == "unique_together":
ut = model._meta.original_attrs["unique_together"]
options[name] = set(normalize_together(ut))
elif name == "index_together":
it = model._meta.original_attrs["index_together"]
options[name] = set(normalize_together(it))
elif name == "indexes":
indexes = [idx.clone() for idx in model._meta.indexes]
for index in indexes:
if not index.name:
index.set_name_with_model(model)
options["indexes"] = indexes
elif name == "constraints":
options["constraints"] = [
con.clone() for con in model._meta.constraints
]
else:
options[name] = model._meta.original_attrs[name]
# If we're ignoring relationships, remove all field-listing model
# options (that option basically just means "make a stub model")
if exclude_rels:
for key in ["unique_together", "index_together", "order_with_respect_to"]:
if key in options:
del options[key]
# Private fields are ignored, so remove options that refer to them.
elif options.get("order_with_respect_to") in {
field.name for field in model._meta.private_fields
}:
del options["order_with_respect_to"]
def flatten_bases(model):
bases = []
for base in model.__bases__:
if hasattr(base, "_meta") and base._meta.abstract:
bases.extend(flatten_bases(base))
else:
bases.append(base)
return bases
# We can't rely on __mro__ directly because we only want to flatten
# abstract models and not the whole tree. However by recursing on
# __bases__ we may end up with duplicates and ordering issues, we
# therefore discard any duplicates and reorder the bases according
# to their index in the MRO.
flattened_bases = sorted(
set(flatten_bases(model)), key=lambda x: model.__mro__.index(x)
)
# Make our record
bases = tuple(
(base._meta.label_lower if hasattr(base, "_meta") else base)
for base in flattened_bases
)
# Ensure at least one base inherits from models.Model
if not any(
(isinstance(base, str) or issubclass(base, models.Model)) for base in bases
):
bases = (models.Model,)
managers = []
manager_names = set()
default_manager_shim = None
for manager in model._meta.managers:
if manager.name in manager_names:
# Skip overridden managers.
continue
elif manager.use_in_migrations:
# Copy managers usable in migrations.
new_manager = copy.copy(manager)
new_manager._set_creation_counter()
elif manager is model._base_manager or manager is model._default_manager:
# Shim custom managers used as default and base managers.
new_manager = models.Manager()
new_manager.model = manager.model
new_manager.name = manager.name
if manager is model._default_manager:
default_manager_shim = new_manager
else:
continue
manager_names.add(manager.name)
managers.append((manager.name, new_manager))
# Ignore a shimmed default manager called objects if it's the only one.
if managers == [("objects", default_manager_shim)]:
managers = []
# Construct the new ModelState
return cls(
model._meta.app_label,
model._meta.object_name,
fields,
options,
bases,
managers,
)
def construct_managers(self):
"""Deep-clone the managers using deconstruction."""
# Sort all managers by their creation counter
sorted_managers = sorted(self.managers, key=lambda v: v[1].creation_counter)
for mgr_name, manager in sorted_managers:
as_manager, manager_path, qs_path, args, kwargs = manager.deconstruct()
if as_manager:
qs_class = import_string(qs_path)
yield mgr_name, qs_class.as_manager()
else:
manager_class = import_string(manager_path)
yield mgr_name, manager_class(*args, **kwargs)
def clone(self):
"""Return an exact copy of this ModelState."""
return self.__class__(
app_label=self.app_label,
name=self.name,
fields=dict(self.fields),
# Since options are shallow-copied here, operations such as
# AddIndex must replace their option (e.g 'indexes') rather
# than mutating it.
options=dict(self.options),
bases=self.bases,
managers=list(self.managers),
)
def render(self, apps):
"""Create a Model object from our current state into the given apps."""
# First, make a Meta object
meta_contents = {"app_label": self.app_label, "apps": apps, **self.options}
meta = type("Meta", (), meta_contents)
# Then, work out our bases
try:
bases = tuple(
(apps.get_model(base) if isinstance(base, str) else base)
for base in self.bases
)
except LookupError:
raise InvalidBasesError(
"Cannot resolve one or more bases from %r" % (self.bases,)
)
# Clone fields for the body, add other bits.
body = {name: field.clone() for name, field in self.fields.items()}
body["Meta"] = meta
body["__module__"] = "__fake__"
# Restore managers
body.update(self.construct_managers())
# Then, make a Model object (apps.register_model is called in __new__)
return type(self.name, bases, body)
def get_index_by_name(self, name):
for index in self.options["indexes"]:
if index.name == name:
return index
raise ValueError("No index named %s on model %s" % (name, self.name))
def get_constraint_by_name(self, name):
for constraint in self.options["constraints"]:
if constraint.name == name:
return constraint
raise ValueError("No constraint named %s on model %s" % (name, self.name))
def __repr__(self):
return "<%s: '%s.%s'>" % (self.__class__.__name__, self.app_label, self.name)
def __eq__(self, other):
return (
(self.app_label == other.app_label)
and (self.name == other.name)
and (len(self.fields) == len(other.fields))
and all(
k1 == k2 and f1.deconstruct()[1:] == f2.deconstruct()[1:]
for (k1, f1), (k2, f2) in zip(
sorted(self.fields.items()),
sorted(other.fields.items()),
)
)
and (self.options == other.options)
and (self.bases == other.bases)
and (self.managers == other.managers)
)
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/state.py
|
Python
|
mit
| 40,654 |
import datetime
import re
from collections import namedtuple
from django.db.models.fields.related import RECURSIVE_RELATIONSHIP_CONSTANT
FieldReference = namedtuple("FieldReference", "to through")
COMPILED_REGEX_TYPE = type(re.compile(""))
class RegexObject:
def __init__(self, obj):
self.pattern = obj.pattern
self.flags = obj.flags
def __eq__(self, other):
if not isinstance(other, RegexObject):
return NotImplemented
return self.pattern == other.pattern and self.flags == other.flags
def get_migration_name_timestamp():
return datetime.datetime.now().strftime("%Y%m%d_%H%M")
def resolve_relation(model, app_label=None, model_name=None):
"""
Turn a model class or model reference string and return a model tuple.
app_label and model_name are used to resolve the scope of recursive and
unscoped model relationship.
"""
if isinstance(model, str):
if model == RECURSIVE_RELATIONSHIP_CONSTANT:
if app_label is None or model_name is None:
raise TypeError(
"app_label and model_name must be provided to resolve "
"recursive relationships."
)
return app_label, model_name
if "." in model:
app_label, model_name = model.split(".", 1)
return app_label, model_name.lower()
if app_label is None:
raise TypeError(
"app_label must be provided to resolve unscoped model relationships."
)
return app_label, model.lower()
return model._meta.app_label, model._meta.model_name
def field_references(
model_tuple,
field,
reference_model_tuple,
reference_field_name=None,
reference_field=None,
):
"""
Return either False or a FieldReference if `field` references provided
context.
False positives can be returned if `reference_field_name` is provided
without `reference_field` because of the introspection limitation it
incurs. This should not be an issue when this function is used to determine
whether or not an optimization can take place.
"""
remote_field = field.remote_field
if not remote_field:
return False
references_to = None
references_through = None
if resolve_relation(remote_field.model, *model_tuple) == reference_model_tuple:
to_fields = getattr(field, "to_fields", None)
if (
reference_field_name is None
or
# Unspecified to_field(s).
to_fields is None
or
# Reference to primary key.
(
None in to_fields
and (reference_field is None or reference_field.primary_key)
)
or
# Reference to field.
reference_field_name in to_fields
):
references_to = (remote_field, to_fields)
through = getattr(remote_field, "through", None)
if through and resolve_relation(through, *model_tuple) == reference_model_tuple:
through_fields = remote_field.through_fields
if (
reference_field_name is None
or
# Unspecified through_fields.
through_fields is None
or
# Reference to field.
reference_field_name in through_fields
):
references_through = (remote_field, through_fields)
if not (references_to or references_through):
return False
return FieldReference(references_to, references_through)
def get_references(state, model_tuple, field_tuple=()):
"""
Generator of (model_state, name, field, reference) referencing
provided context.
If field_tuple is provided only references to this particular field of
model_tuple will be generated.
"""
for state_model_tuple, model_state in state.models.items():
for name, field in model_state.fields.items():
reference = field_references(
state_model_tuple, field, model_tuple, *field_tuple
)
if reference:
yield model_state, name, field, reference
def field_is_referenced(state, model_tuple, field_tuple):
"""Return whether `field_tuple` is referenced by any state models."""
return next(get_references(state, model_tuple, field_tuple), None) is not None
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/utils.py
|
Python
|
mit
| 4,401 |
import os
import re
from importlib import import_module
from django import get_version
from django.apps import apps
# SettingsReference imported for backwards compatibility in Django 2.2.
from django.conf import SettingsReference # NOQA
from django.db import migrations
from django.db.migrations.loader import MigrationLoader
from django.db.migrations.serializer import Serializer, serializer_factory
from django.utils.inspect import get_func_args
from django.utils.module_loading import module_dir
from django.utils.timezone import now
class OperationWriter:
def __init__(self, operation, indentation=2):
self.operation = operation
self.buff = []
self.indentation = indentation
def serialize(self):
def _write(_arg_name, _arg_value):
if _arg_name in self.operation.serialization_expand_args and isinstance(
_arg_value, (list, tuple, dict)
):
if isinstance(_arg_value, dict):
self.feed("%s={" % _arg_name)
self.indent()
for key, value in _arg_value.items():
key_string, key_imports = MigrationWriter.serialize(key)
arg_string, arg_imports = MigrationWriter.serialize(value)
args = arg_string.splitlines()
if len(args) > 1:
self.feed("%s: %s" % (key_string, args[0]))
for arg in args[1:-1]:
self.feed(arg)
self.feed("%s," % args[-1])
else:
self.feed("%s: %s," % (key_string, arg_string))
imports.update(key_imports)
imports.update(arg_imports)
self.unindent()
self.feed("},")
else:
self.feed("%s=[" % _arg_name)
self.indent()
for item in _arg_value:
arg_string, arg_imports = MigrationWriter.serialize(item)
args = arg_string.splitlines()
if len(args) > 1:
for arg in args[:-1]:
self.feed(arg)
self.feed("%s," % args[-1])
else:
self.feed("%s," % arg_string)
imports.update(arg_imports)
self.unindent()
self.feed("],")
else:
arg_string, arg_imports = MigrationWriter.serialize(_arg_value)
args = arg_string.splitlines()
if len(args) > 1:
self.feed("%s=%s" % (_arg_name, args[0]))
for arg in args[1:-1]:
self.feed(arg)
self.feed("%s," % args[-1])
else:
self.feed("%s=%s," % (_arg_name, arg_string))
imports.update(arg_imports)
imports = set()
name, args, kwargs = self.operation.deconstruct()
operation_args = get_func_args(self.operation.__init__)
# See if this operation is in django.db.migrations. If it is,
# We can just use the fact we already have that imported,
# otherwise, we need to add an import for the operation class.
if getattr(migrations, name, None) == self.operation.__class__:
self.feed("migrations.%s(" % name)
else:
imports.add("import %s" % (self.operation.__class__.__module__))
self.feed("%s.%s(" % (self.operation.__class__.__module__, name))
self.indent()
for i, arg in enumerate(args):
arg_value = arg
arg_name = operation_args[i]
_write(arg_name, arg_value)
i = len(args)
# Only iterate over remaining arguments
for arg_name in operation_args[i:]:
if arg_name in kwargs: # Don't sort to maintain signature order
arg_value = kwargs[arg_name]
_write(arg_name, arg_value)
self.unindent()
self.feed("),")
return self.render(), imports
def indent(self):
self.indentation += 1
def unindent(self):
self.indentation -= 1
def feed(self, line):
self.buff.append(" " * (self.indentation * 4) + line)
def render(self):
return "\n".join(self.buff)
class MigrationWriter:
"""
Take a Migration instance and is able to produce the contents
of the migration file from it.
"""
def __init__(self, migration, include_header=True):
self.migration = migration
self.include_header = include_header
self.needs_manual_porting = False
def as_string(self):
"""Return a string of the file contents."""
items = {
"replaces_str": "",
"initial_str": "",
}
imports = set()
# Deconstruct operations
operations = []
for operation in self.migration.operations:
operation_string, operation_imports = OperationWriter(operation).serialize()
imports.update(operation_imports)
operations.append(operation_string)
items["operations"] = "\n".join(operations) + "\n" if operations else ""
# Format dependencies and write out swappable dependencies right
dependencies = []
for dependency in self.migration.dependencies:
if dependency[0] == "__setting__":
dependencies.append(
" migrations.swappable_dependency(settings.%s),"
% dependency[1]
)
imports.add("from django.conf import settings")
else:
dependencies.append(" %s," % self.serialize(dependency)[0])
items["dependencies"] = "\n".join(dependencies) + "\n" if dependencies else ""
# Format imports nicely, swapping imports of functions from migration files
# for comments
migration_imports = set()
for line in list(imports):
if re.match(r"^import (.*)\.\d+[^\s]*$", line):
migration_imports.add(line.split("import")[1].strip())
imports.remove(line)
self.needs_manual_porting = True
# django.db.migrations is always used, but models import may not be.
# If models import exists, merge it with migrations import.
if "from django.db import models" in imports:
imports.discard("from django.db import models")
imports.add("from django.db import migrations, models")
else:
imports.add("from django.db import migrations")
# Sort imports by the package / module to be imported (the part after
# "from" in "from ... import ..." or after "import" in "import ...").
sorted_imports = sorted(imports, key=lambda i: i.split()[1])
items["imports"] = "\n".join(sorted_imports) + "\n" if imports else ""
if migration_imports:
items["imports"] += (
"\n\n# Functions from the following migrations need manual "
"copying.\n# Move them and any dependencies into this file, "
"then update the\n# RunPython operations to refer to the local "
"versions:\n# %s"
) % "\n# ".join(sorted(migration_imports))
# If there's a replaces, make a string for it
if self.migration.replaces:
items["replaces_str"] = (
"\n replaces = %s\n" % self.serialize(self.migration.replaces)[0]
)
# Hinting that goes into comment
if self.include_header:
items["migration_header"] = MIGRATION_HEADER_TEMPLATE % {
"version": get_version(),
"timestamp": now().strftime("%Y-%m-%d %H:%M"),
}
else:
items["migration_header"] = ""
if self.migration.initial:
items["initial_str"] = "\n initial = True\n"
return MIGRATION_TEMPLATE % items
@property
def basedir(self):
migrations_package_name, _ = MigrationLoader.migrations_module(
self.migration.app_label
)
if migrations_package_name is None:
raise ValueError(
"Django can't create migrations for app '%s' because "
"migrations have been disabled via the MIGRATION_MODULES "
"setting." % self.migration.app_label
)
# See if we can import the migrations module directly
try:
migrations_module = import_module(migrations_package_name)
except ImportError:
pass
else:
try:
return module_dir(migrations_module)
except ValueError:
pass
# Alright, see if it's a direct submodule of the app
app_config = apps.get_app_config(self.migration.app_label)
(
maybe_app_name,
_,
migrations_package_basename,
) = migrations_package_name.rpartition(".")
if app_config.name == maybe_app_name:
return os.path.join(app_config.path, migrations_package_basename)
# In case of using MIGRATION_MODULES setting and the custom package
# doesn't exist, create one, starting from an existing package
existing_dirs, missing_dirs = migrations_package_name.split("."), []
while existing_dirs:
missing_dirs.insert(0, existing_dirs.pop(-1))
try:
base_module = import_module(".".join(existing_dirs))
except (ImportError, ValueError):
continue
else:
try:
base_dir = module_dir(base_module)
except ValueError:
continue
else:
break
else:
raise ValueError(
"Could not locate an appropriate location to create "
"migrations package %s. Make sure the toplevel "
"package exists and can be imported." % migrations_package_name
)
final_dir = os.path.join(base_dir, *missing_dirs)
os.makedirs(final_dir, exist_ok=True)
for missing_dir in missing_dirs:
base_dir = os.path.join(base_dir, missing_dir)
with open(os.path.join(base_dir, "__init__.py"), "w"):
pass
return final_dir
@property
def filename(self):
return "%s.py" % self.migration.name
@property
def path(self):
return os.path.join(self.basedir, self.filename)
@classmethod
def serialize(cls, value):
return serializer_factory(value).serialize()
@classmethod
def register_serializer(cls, type_, serializer):
Serializer.register(type_, serializer)
@classmethod
def unregister_serializer(cls, type_):
Serializer.unregister(type_)
MIGRATION_HEADER_TEMPLATE = """\
# Generated by Django %(version)s on %(timestamp)s
"""
MIGRATION_TEMPLATE = """\
%(migration_header)s%(imports)s
class Migration(migrations.Migration):
%(replaces_str)s%(initial_str)s
dependencies = [
%(dependencies)s\
]
operations = [
%(operations)s\
]
"""
|
castiel248/Convert
|
Lib/site-packages/django/db/migrations/writer.py
|
Python
|
mit
| 11,458 |
from django.core.exceptions import ObjectDoesNotExist
from django.db.models import signals
from django.db.models.aggregates import * # NOQA
from django.db.models.aggregates import __all__ as aggregates_all
from django.db.models.constraints import * # NOQA
from django.db.models.constraints import __all__ as constraints_all
from django.db.models.deletion import (
CASCADE,
DO_NOTHING,
PROTECT,
RESTRICT,
SET,
SET_DEFAULT,
SET_NULL,
ProtectedError,
RestrictedError,
)
from django.db.models.enums import * # NOQA
from django.db.models.enums import __all__ as enums_all
from django.db.models.expressions import (
Case,
Exists,
Expression,
ExpressionList,
ExpressionWrapper,
F,
Func,
OrderBy,
OuterRef,
RowRange,
Subquery,
Value,
ValueRange,
When,
Window,
WindowFrame,
)
from django.db.models.fields import * # NOQA
from django.db.models.fields import __all__ as fields_all
from django.db.models.fields.files import FileField, ImageField
from django.db.models.fields.json import JSONField
from django.db.models.fields.proxy import OrderWrt
from django.db.models.indexes import * # NOQA
from django.db.models.indexes import __all__ as indexes_all
from django.db.models.lookups import Lookup, Transform
from django.db.models.manager import Manager
from django.db.models.query import Prefetch, QuerySet, prefetch_related_objects
from django.db.models.query_utils import FilteredRelation, Q
# Imports that would create circular imports if sorted
from django.db.models.base import DEFERRED, Model # isort:skip
from django.db.models.fields.related import ( # isort:skip
ForeignKey,
ForeignObject,
OneToOneField,
ManyToManyField,
ForeignObjectRel,
ManyToOneRel,
ManyToManyRel,
OneToOneRel,
)
__all__ = aggregates_all + constraints_all + enums_all + fields_all + indexes_all
__all__ += [
"ObjectDoesNotExist",
"signals",
"CASCADE",
"DO_NOTHING",
"PROTECT",
"RESTRICT",
"SET",
"SET_DEFAULT",
"SET_NULL",
"ProtectedError",
"RestrictedError",
"Case",
"Exists",
"Expression",
"ExpressionList",
"ExpressionWrapper",
"F",
"Func",
"OrderBy",
"OuterRef",
"RowRange",
"Subquery",
"Value",
"ValueRange",
"When",
"Window",
"WindowFrame",
"FileField",
"ImageField",
"JSONField",
"OrderWrt",
"Lookup",
"Transform",
"Manager",
"Prefetch",
"Q",
"QuerySet",
"prefetch_related_objects",
"DEFERRED",
"Model",
"FilteredRelation",
"ForeignKey",
"ForeignObject",
"OneToOneField",
"ManyToManyField",
"ForeignObjectRel",
"ManyToOneRel",
"ManyToManyRel",
"OneToOneRel",
]
|
castiel248/Convert
|
Lib/site-packages/django/db/models/__init__.py
|
Python
|
mit
| 2,774 |
"""
Classes to represent the definitions of aggregate functions.
"""
from django.core.exceptions import FieldError, FullResultSet
from django.db.models.expressions import Case, Func, Star, Value, When
from django.db.models.fields import IntegerField
from django.db.models.functions.comparison import Coalesce
from django.db.models.functions.mixins import (
FixDurationInputMixin,
NumericOutputFieldMixin,
)
__all__ = [
"Aggregate",
"Avg",
"Count",
"Max",
"Min",
"StdDev",
"Sum",
"Variance",
]
class Aggregate(Func):
template = "%(function)s(%(distinct)s%(expressions)s)"
contains_aggregate = True
name = None
filter_template = "%s FILTER (WHERE %%(filter)s)"
window_compatible = True
allow_distinct = False
empty_result_set_value = None
def __init__(
self, *expressions, distinct=False, filter=None, default=None, **extra
):
if distinct and not self.allow_distinct:
raise TypeError("%s does not allow distinct." % self.__class__.__name__)
if default is not None and self.empty_result_set_value is not None:
raise TypeError(f"{self.__class__.__name__} does not allow default.")
self.distinct = distinct
self.filter = filter
self.default = default
super().__init__(*expressions, **extra)
def get_source_fields(self):
# Don't return the filter expression since it's not a source field.
return [e._output_field_or_none for e in super().get_source_expressions()]
def get_source_expressions(self):
source_expressions = super().get_source_expressions()
if self.filter:
return source_expressions + [self.filter]
return source_expressions
def set_source_expressions(self, exprs):
self.filter = self.filter and exprs.pop()
return super().set_source_expressions(exprs)
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
# Aggregates are not allowed in UPDATE queries, so ignore for_save
c = super().resolve_expression(query, allow_joins, reuse, summarize)
c.filter = c.filter and c.filter.resolve_expression(
query, allow_joins, reuse, summarize
)
if summarize:
# Summarized aggregates cannot refer to summarized aggregates.
for ref in c.get_refs():
if query.annotations[ref].is_summary:
raise FieldError(
f"Cannot compute {c.name}('{ref}'): '{ref}' is an aggregate"
)
elif not self.is_summary:
# Call Aggregate.get_source_expressions() to avoid
# returning self.filter and including that in this loop.
expressions = super(Aggregate, c).get_source_expressions()
for index, expr in enumerate(expressions):
if expr.contains_aggregate:
before_resolved = self.get_source_expressions()[index]
name = (
before_resolved.name
if hasattr(before_resolved, "name")
else repr(before_resolved)
)
raise FieldError(
"Cannot compute %s('%s'): '%s' is an aggregate"
% (c.name, name, name)
)
if (default := c.default) is None:
return c
if hasattr(default, "resolve_expression"):
default = default.resolve_expression(query, allow_joins, reuse, summarize)
if default._output_field_or_none is None:
default.output_field = c._output_field_or_none
else:
default = Value(default, c._output_field_or_none)
c.default = None # Reset the default argument before wrapping.
coalesce = Coalesce(c, default, output_field=c._output_field_or_none)
coalesce.is_summary = c.is_summary
return coalesce
@property
def default_alias(self):
expressions = self.get_source_expressions()
if len(expressions) == 1 and hasattr(expressions[0], "name"):
return "%s__%s" % (expressions[0].name, self.name.lower())
raise TypeError("Complex expressions require an alias")
def get_group_by_cols(self):
return []
def as_sql(self, compiler, connection, **extra_context):
extra_context["distinct"] = "DISTINCT " if self.distinct else ""
if self.filter:
if connection.features.supports_aggregate_filter_clause:
try:
filter_sql, filter_params = self.filter.as_sql(compiler, connection)
except FullResultSet:
pass
else:
template = self.filter_template % extra_context.get(
"template", self.template
)
sql, params = super().as_sql(
compiler,
connection,
template=template,
filter=filter_sql,
**extra_context,
)
return sql, (*params, *filter_params)
else:
copy = self.copy()
copy.filter = None
source_expressions = copy.get_source_expressions()
condition = When(self.filter, then=source_expressions[0])
copy.set_source_expressions([Case(condition)] + source_expressions[1:])
return super(Aggregate, copy).as_sql(
compiler, connection, **extra_context
)
return super().as_sql(compiler, connection, **extra_context)
def _get_repr_options(self):
options = super()._get_repr_options()
if self.distinct:
options["distinct"] = self.distinct
if self.filter:
options["filter"] = self.filter
return options
class Avg(FixDurationInputMixin, NumericOutputFieldMixin, Aggregate):
function = "AVG"
name = "Avg"
allow_distinct = True
class Count(Aggregate):
function = "COUNT"
name = "Count"
output_field = IntegerField()
allow_distinct = True
empty_result_set_value = 0
def __init__(self, expression, filter=None, **extra):
if expression == "*":
expression = Star()
if isinstance(expression, Star) and filter is not None:
raise ValueError("Star cannot be used with filter. Please specify a field.")
super().__init__(expression, filter=filter, **extra)
class Max(Aggregate):
function = "MAX"
name = "Max"
class Min(Aggregate):
function = "MIN"
name = "Min"
class StdDev(NumericOutputFieldMixin, Aggregate):
name = "StdDev"
def __init__(self, expression, sample=False, **extra):
self.function = "STDDEV_SAMP" if sample else "STDDEV_POP"
super().__init__(expression, **extra)
def _get_repr_options(self):
return {**super()._get_repr_options(), "sample": self.function == "STDDEV_SAMP"}
class Sum(FixDurationInputMixin, Aggregate):
function = "SUM"
name = "Sum"
allow_distinct = True
class Variance(NumericOutputFieldMixin, Aggregate):
name = "Variance"
def __init__(self, expression, sample=False, **extra):
self.function = "VAR_SAMP" if sample else "VAR_POP"
super().__init__(expression, **extra)
def _get_repr_options(self):
return {**super()._get_repr_options(), "sample": self.function == "VAR_SAMP"}
|
castiel248/Convert
|
Lib/site-packages/django/db/models/aggregates.py
|
Python
|
mit
| 7,642 |
import copy
import inspect
import warnings
from functools import partialmethod
from itertools import chain
from asgiref.sync import sync_to_async
import django
from django.apps import apps
from django.conf import settings
from django.core import checks
from django.core.exceptions import (
NON_FIELD_ERRORS,
FieldDoesNotExist,
FieldError,
MultipleObjectsReturned,
ObjectDoesNotExist,
ValidationError,
)
from django.db import (
DJANGO_VERSION_PICKLE_KEY,
DatabaseError,
connection,
connections,
router,
transaction,
)
from django.db.models import NOT_PROVIDED, ExpressionWrapper, IntegerField, Max, Value
from django.db.models.constants import LOOKUP_SEP
from django.db.models.constraints import CheckConstraint, UniqueConstraint
from django.db.models.deletion import CASCADE, Collector
from django.db.models.expressions import RawSQL
from django.db.models.fields.related import (
ForeignObjectRel,
OneToOneField,
lazy_related_operation,
resolve_relation,
)
from django.db.models.functions import Coalesce
from django.db.models.manager import Manager
from django.db.models.options import Options
from django.db.models.query import F, Q
from django.db.models.signals import (
class_prepared,
post_init,
post_save,
pre_init,
pre_save,
)
from django.db.models.utils import AltersData, make_model_tuple
from django.utils.encoding import force_str
from django.utils.hashable import make_hashable
from django.utils.text import capfirst, get_text_list
from django.utils.translation import gettext_lazy as _
class Deferred:
def __repr__(self):
return "<Deferred field>"
def __str__(self):
return "<Deferred field>"
DEFERRED = Deferred()
def subclass_exception(name, bases, module, attached_to):
"""
Create exception subclass. Used by ModelBase below.
The exception is created in a way that allows it to be pickled, assuming
that the returned exception class will be added as an attribute to the
'attached_to' class.
"""
return type(
name,
bases,
{
"__module__": module,
"__qualname__": "%s.%s" % (attached_to.__qualname__, name),
},
)
def _has_contribute_to_class(value):
# Only call contribute_to_class() if it's bound.
return not inspect.isclass(value) and hasattr(value, "contribute_to_class")
class ModelBase(type):
"""Metaclass for all models."""
def __new__(cls, name, bases, attrs, **kwargs):
super_new = super().__new__
# Also ensure initialization is only performed for subclasses of Model
# (excluding Model class itself).
parents = [b for b in bases if isinstance(b, ModelBase)]
if not parents:
return super_new(cls, name, bases, attrs)
# Create the class.
module = attrs.pop("__module__")
new_attrs = {"__module__": module}
classcell = attrs.pop("__classcell__", None)
if classcell is not None:
new_attrs["__classcell__"] = classcell
attr_meta = attrs.pop("Meta", None)
# Pass all attrs without a (Django-specific) contribute_to_class()
# method to type.__new__() so that they're properly initialized
# (i.e. __set_name__()).
contributable_attrs = {}
for obj_name, obj in attrs.items():
if _has_contribute_to_class(obj):
contributable_attrs[obj_name] = obj
else:
new_attrs[obj_name] = obj
new_class = super_new(cls, name, bases, new_attrs, **kwargs)
abstract = getattr(attr_meta, "abstract", False)
meta = attr_meta or getattr(new_class, "Meta", None)
base_meta = getattr(new_class, "_meta", None)
app_label = None
# Look for an application configuration to attach the model to.
app_config = apps.get_containing_app_config(module)
if getattr(meta, "app_label", None) is None:
if app_config is None:
if not abstract:
raise RuntimeError(
"Model class %s.%s doesn't declare an explicit "
"app_label and isn't in an application in "
"INSTALLED_APPS." % (module, name)
)
else:
app_label = app_config.label
new_class.add_to_class("_meta", Options(meta, app_label))
if not abstract:
new_class.add_to_class(
"DoesNotExist",
subclass_exception(
"DoesNotExist",
tuple(
x.DoesNotExist
for x in parents
if hasattr(x, "_meta") and not x._meta.abstract
)
or (ObjectDoesNotExist,),
module,
attached_to=new_class,
),
)
new_class.add_to_class(
"MultipleObjectsReturned",
subclass_exception(
"MultipleObjectsReturned",
tuple(
x.MultipleObjectsReturned
for x in parents
if hasattr(x, "_meta") and not x._meta.abstract
)
or (MultipleObjectsReturned,),
module,
attached_to=new_class,
),
)
if base_meta and not base_meta.abstract:
# Non-abstract child classes inherit some attributes from their
# non-abstract parent (unless an ABC comes before it in the
# method resolution order).
if not hasattr(meta, "ordering"):
new_class._meta.ordering = base_meta.ordering
if not hasattr(meta, "get_latest_by"):
new_class._meta.get_latest_by = base_meta.get_latest_by
is_proxy = new_class._meta.proxy
# If the model is a proxy, ensure that the base class
# hasn't been swapped out.
if is_proxy and base_meta and base_meta.swapped:
raise TypeError(
"%s cannot proxy the swapped model '%s'." % (name, base_meta.swapped)
)
# Add remaining attributes (those with a contribute_to_class() method)
# to the class.
for obj_name, obj in contributable_attrs.items():
new_class.add_to_class(obj_name, obj)
# All the fields of any type declared on this model
new_fields = chain(
new_class._meta.local_fields,
new_class._meta.local_many_to_many,
new_class._meta.private_fields,
)
field_names = {f.name for f in new_fields}
# Basic setup for proxy models.
if is_proxy:
base = None
for parent in [kls for kls in parents if hasattr(kls, "_meta")]:
if parent._meta.abstract:
if parent._meta.fields:
raise TypeError(
"Abstract base class containing model fields not "
"permitted for proxy model '%s'." % name
)
else:
continue
if base is None:
base = parent
elif parent._meta.concrete_model is not base._meta.concrete_model:
raise TypeError(
"Proxy model '%s' has more than one non-abstract model base "
"class." % name
)
if base is None:
raise TypeError(
"Proxy model '%s' has no non-abstract model base class." % name
)
new_class._meta.setup_proxy(base)
new_class._meta.concrete_model = base._meta.concrete_model
else:
new_class._meta.concrete_model = new_class
# Collect the parent links for multi-table inheritance.
parent_links = {}
for base in reversed([new_class] + parents):
# Conceptually equivalent to `if base is Model`.
if not hasattr(base, "_meta"):
continue
# Skip concrete parent classes.
if base != new_class and not base._meta.abstract:
continue
# Locate OneToOneField instances.
for field in base._meta.local_fields:
if isinstance(field, OneToOneField) and field.remote_field.parent_link:
related = resolve_relation(new_class, field.remote_field.model)
parent_links[make_model_tuple(related)] = field
# Track fields inherited from base models.
inherited_attributes = set()
# Do the appropriate setup for any model parents.
for base in new_class.mro():
if base not in parents or not hasattr(base, "_meta"):
# Things without _meta aren't functional models, so they're
# uninteresting parents.
inherited_attributes.update(base.__dict__)
continue
parent_fields = base._meta.local_fields + base._meta.local_many_to_many
if not base._meta.abstract:
# Check for clashes between locally declared fields and those
# on the base classes.
for field in parent_fields:
if field.name in field_names:
raise FieldError(
"Local field %r in class %r clashes with field of "
"the same name from base class %r."
% (
field.name,
name,
base.__name__,
)
)
else:
inherited_attributes.add(field.name)
# Concrete classes...
base = base._meta.concrete_model
base_key = make_model_tuple(base)
if base_key in parent_links:
field = parent_links[base_key]
elif not is_proxy:
attr_name = "%s_ptr" % base._meta.model_name
field = OneToOneField(
base,
on_delete=CASCADE,
name=attr_name,
auto_created=True,
parent_link=True,
)
if attr_name in field_names:
raise FieldError(
"Auto-generated field '%s' in class %r for "
"parent_link to base class %r clashes with "
"declared field of the same name."
% (
attr_name,
name,
base.__name__,
)
)
# Only add the ptr field if it's not already present;
# e.g. migrations will already have it specified
if not hasattr(new_class, attr_name):
new_class.add_to_class(attr_name, field)
else:
field = None
new_class._meta.parents[base] = field
else:
base_parents = base._meta.parents.copy()
# Add fields from abstract base class if it wasn't overridden.
for field in parent_fields:
if (
field.name not in field_names
and field.name not in new_class.__dict__
and field.name not in inherited_attributes
):
new_field = copy.deepcopy(field)
new_class.add_to_class(field.name, new_field)
# Replace parent links defined on this base by the new
# field. It will be appropriately resolved if required.
if field.one_to_one:
for parent, parent_link in base_parents.items():
if field == parent_link:
base_parents[parent] = new_field
# Pass any non-abstract parent classes onto child.
new_class._meta.parents.update(base_parents)
# Inherit private fields (like GenericForeignKey) from the parent
# class
for field in base._meta.private_fields:
if field.name in field_names:
if not base._meta.abstract:
raise FieldError(
"Local field %r in class %r clashes with field of "
"the same name from base class %r."
% (
field.name,
name,
base.__name__,
)
)
else:
field = copy.deepcopy(field)
if not base._meta.abstract:
field.mti_inherited = True
new_class.add_to_class(field.name, field)
# Copy indexes so that index names are unique when models extend an
# abstract model.
new_class._meta.indexes = [
copy.deepcopy(idx) for idx in new_class._meta.indexes
]
if abstract:
# Abstract base models can't be instantiated and don't appear in
# the list of models for an app. We do the final setup for them a
# little differently from normal models.
attr_meta.abstract = False
new_class.Meta = attr_meta
return new_class
new_class._prepare()
new_class._meta.apps.register_model(new_class._meta.app_label, new_class)
return new_class
def add_to_class(cls, name, value):
if _has_contribute_to_class(value):
value.contribute_to_class(cls, name)
else:
setattr(cls, name, value)
def _prepare(cls):
"""Create some methods once self._meta has been populated."""
opts = cls._meta
opts._prepare(cls)
if opts.order_with_respect_to:
cls.get_next_in_order = partialmethod(
cls._get_next_or_previous_in_order, is_next=True
)
cls.get_previous_in_order = partialmethod(
cls._get_next_or_previous_in_order, is_next=False
)
# Defer creating accessors on the foreign class until it has been
# created and registered. If remote_field is None, we're ordering
# with respect to a GenericForeignKey and don't know what the
# foreign class is - we'll add those accessors later in
# contribute_to_class().
if opts.order_with_respect_to.remote_field:
wrt = opts.order_with_respect_to
remote = wrt.remote_field.model
lazy_related_operation(make_foreign_order_accessors, cls, remote)
# Give the class a docstring -- its definition.
if cls.__doc__ is None:
cls.__doc__ = "%s(%s)" % (
cls.__name__,
", ".join(f.name for f in opts.fields),
)
get_absolute_url_override = settings.ABSOLUTE_URL_OVERRIDES.get(
opts.label_lower
)
if get_absolute_url_override:
setattr(cls, "get_absolute_url", get_absolute_url_override)
if not opts.managers:
if any(f.name == "objects" for f in opts.fields):
raise ValueError(
"Model %s must specify a custom Manager, because it has a "
"field named 'objects'." % cls.__name__
)
manager = Manager()
manager.auto_created = True
cls.add_to_class("objects", manager)
# Set the name of _meta.indexes. This can't be done in
# Options.contribute_to_class() because fields haven't been added to
# the model at that point.
for index in cls._meta.indexes:
if not index.name:
index.set_name_with_model(cls)
class_prepared.send(sender=cls)
@property
def _base_manager(cls):
return cls._meta.base_manager
@property
def _default_manager(cls):
return cls._meta.default_manager
class ModelStateFieldsCacheDescriptor:
def __get__(self, instance, cls=None):
if instance is None:
return self
res = instance.fields_cache = {}
return res
class ModelState:
"""Store model instance state."""
db = None
# If true, uniqueness validation checks will consider this a new, unsaved
# object. Necessary for correct validation of new instances of objects with
# explicit (non-auto) PKs. This impacts validation only; it has no effect
# on the actual save.
adding = True
fields_cache = ModelStateFieldsCacheDescriptor()
class Model(AltersData, metaclass=ModelBase):
def __init__(self, *args, **kwargs):
# Alias some things as locals to avoid repeat global lookups
cls = self.__class__
opts = self._meta
_setattr = setattr
_DEFERRED = DEFERRED
if opts.abstract:
raise TypeError("Abstract models cannot be instantiated.")
pre_init.send(sender=cls, args=args, kwargs=kwargs)
# Set up the storage for instance state
self._state = ModelState()
# There is a rather weird disparity here; if kwargs, it's set, then args
# overrides it. It should be one or the other; don't duplicate the work
# The reason for the kwargs check is that standard iterator passes in by
# args, and instantiation for iteration is 33% faster.
if len(args) > len(opts.concrete_fields):
# Daft, but matches old exception sans the err msg.
raise IndexError("Number of args exceeds number of fields")
if not kwargs:
fields_iter = iter(opts.concrete_fields)
# The ordering of the zip calls matter - zip throws StopIteration
# when an iter throws it. So if the first iter throws it, the second
# is *not* consumed. We rely on this, so don't change the order
# without changing the logic.
for val, field in zip(args, fields_iter):
if val is _DEFERRED:
continue
_setattr(self, field.attname, val)
else:
# Slower, kwargs-ready version.
fields_iter = iter(opts.fields)
for val, field in zip(args, fields_iter):
if val is _DEFERRED:
continue
_setattr(self, field.attname, val)
if kwargs.pop(field.name, NOT_PROVIDED) is not NOT_PROVIDED:
raise TypeError(
f"{cls.__qualname__}() got both positional and "
f"keyword arguments for field '{field.name}'."
)
# Now we're left with the unprocessed fields that *must* come from
# keywords, or default.
for field in fields_iter:
is_related_object = False
# Virtual field
if field.attname not in kwargs and field.column is None:
continue
if kwargs:
if isinstance(field.remote_field, ForeignObjectRel):
try:
# Assume object instance was passed in.
rel_obj = kwargs.pop(field.name)
is_related_object = True
except KeyError:
try:
# Object instance wasn't passed in -- must be an ID.
val = kwargs.pop(field.attname)
except KeyError:
val = field.get_default()
else:
try:
val = kwargs.pop(field.attname)
except KeyError:
# This is done with an exception rather than the
# default argument on pop because we don't want
# get_default() to be evaluated, and then not used.
# Refs #12057.
val = field.get_default()
else:
val = field.get_default()
if is_related_object:
# If we are passed a related instance, set it using the
# field.name instead of field.attname (e.g. "user" instead of
# "user_id") so that the object gets properly cached (and type
# checked) by the RelatedObjectDescriptor.
if rel_obj is not _DEFERRED:
_setattr(self, field.name, rel_obj)
else:
if val is not _DEFERRED:
_setattr(self, field.attname, val)
if kwargs:
property_names = opts._property_names
unexpected = ()
for prop, value in kwargs.items():
# Any remaining kwargs must correspond to properties or virtual
# fields.
if prop in property_names:
if value is not _DEFERRED:
_setattr(self, prop, value)
else:
try:
opts.get_field(prop)
except FieldDoesNotExist:
unexpected += (prop,)
else:
if value is not _DEFERRED:
_setattr(self, prop, value)
if unexpected:
unexpected_names = ", ".join(repr(n) for n in unexpected)
raise TypeError(
f"{cls.__name__}() got unexpected keyword arguments: "
f"{unexpected_names}"
)
super().__init__()
post_init.send(sender=cls, instance=self)
@classmethod
def from_db(cls, db, field_names, values):
if len(values) != len(cls._meta.concrete_fields):
values_iter = iter(values)
values = [
next(values_iter) if f.attname in field_names else DEFERRED
for f in cls._meta.concrete_fields
]
new = cls(*values)
new._state.adding = False
new._state.db = db
return new
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def __str__(self):
return "%s object (%s)" % (self.__class__.__name__, self.pk)
def __eq__(self, other):
if not isinstance(other, Model):
return NotImplemented
if self._meta.concrete_model != other._meta.concrete_model:
return False
my_pk = self.pk
if my_pk is None:
return self is other
return my_pk == other.pk
def __hash__(self):
if self.pk is None:
raise TypeError("Model instances without primary key value are unhashable")
return hash(self.pk)
def __reduce__(self):
data = self.__getstate__()
data[DJANGO_VERSION_PICKLE_KEY] = django.__version__
class_id = self._meta.app_label, self._meta.object_name
return model_unpickle, (class_id,), data
def __getstate__(self):
"""Hook to allow choosing the attributes to pickle."""
state = self.__dict__.copy()
state["_state"] = copy.copy(state["_state"])
state["_state"].fields_cache = state["_state"].fields_cache.copy()
# memoryview cannot be pickled, so cast it to bytes and store
# separately.
_memoryview_attrs = []
for attr, value in state.items():
if isinstance(value, memoryview):
_memoryview_attrs.append((attr, bytes(value)))
if _memoryview_attrs:
state["_memoryview_attrs"] = _memoryview_attrs
for attr, value in _memoryview_attrs:
state.pop(attr)
return state
def __setstate__(self, state):
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
if pickled_version:
if pickled_version != django.__version__:
warnings.warn(
"Pickled model instance's Django version %s does not "
"match the current version %s."
% (pickled_version, django.__version__),
RuntimeWarning,
stacklevel=2,
)
else:
warnings.warn(
"Pickled model instance's Django version is not specified.",
RuntimeWarning,
stacklevel=2,
)
if "_memoryview_attrs" in state:
for attr, value in state.pop("_memoryview_attrs"):
state[attr] = memoryview(value)
self.__dict__.update(state)
def _get_pk_val(self, meta=None):
meta = meta or self._meta
return getattr(self, meta.pk.attname)
def _set_pk_val(self, value):
for parent_link in self._meta.parents.values():
if parent_link and parent_link != self._meta.pk:
setattr(self, parent_link.target_field.attname, value)
return setattr(self, self._meta.pk.attname, value)
pk = property(_get_pk_val, _set_pk_val)
def get_deferred_fields(self):
"""
Return a set containing names of deferred fields for this instance.
"""
return {
f.attname
for f in self._meta.concrete_fields
if f.attname not in self.__dict__
}
def refresh_from_db(self, using=None, fields=None):
"""
Reload field values from the database.
By default, the reloading happens from the database this instance was
loaded from, or by the read router if this instance wasn't loaded from
any database. The using parameter will override the default.
Fields can be used to specify which fields to reload. The fields
should be an iterable of field attnames. If fields is None, then
all non-deferred fields are reloaded.
When accessing deferred fields of an instance, the deferred loading
of the field will call this method.
"""
if fields is None:
self._prefetched_objects_cache = {}
else:
prefetched_objects_cache = getattr(self, "_prefetched_objects_cache", ())
for field in fields:
if field in prefetched_objects_cache:
del prefetched_objects_cache[field]
fields.remove(field)
if not fields:
return
if any(LOOKUP_SEP in f for f in fields):
raise ValueError(
'Found "%s" in fields argument. Relations and transforms '
"are not allowed in fields." % LOOKUP_SEP
)
hints = {"instance": self}
db_instance_qs = self.__class__._base_manager.db_manager(
using, hints=hints
).filter(pk=self.pk)
# Use provided fields, if not set then reload all non-deferred fields.
deferred_fields = self.get_deferred_fields()
if fields is not None:
fields = list(fields)
db_instance_qs = db_instance_qs.only(*fields)
elif deferred_fields:
fields = [
f.attname
for f in self._meta.concrete_fields
if f.attname not in deferred_fields
]
db_instance_qs = db_instance_qs.only(*fields)
db_instance = db_instance_qs.get()
non_loaded_fields = db_instance.get_deferred_fields()
for field in self._meta.concrete_fields:
if field.attname in non_loaded_fields:
# This field wasn't refreshed - skip ahead.
continue
setattr(self, field.attname, getattr(db_instance, field.attname))
# Clear cached foreign keys.
if field.is_relation and field.is_cached(self):
field.delete_cached_value(self)
# Clear cached relations.
for field in self._meta.related_objects:
if field.is_cached(self):
field.delete_cached_value(self)
# Clear cached private relations.
for field in self._meta.private_fields:
if field.is_relation and field.is_cached(self):
field.delete_cached_value(self)
self._state.db = db_instance._state.db
async def arefresh_from_db(self, using=None, fields=None):
return await sync_to_async(self.refresh_from_db)(using=using, fields=fields)
def serializable_value(self, field_name):
"""
Return the value of the field name for this instance. If the field is
a foreign key, return the id value instead of the object. If there's
no Field object with this name on the model, return the model
attribute's value.
Used to serialize a field's value (in the serializer, or form output,
for example). Normally, you would just access the attribute directly
and not use this method.
"""
try:
field = self._meta.get_field(field_name)
except FieldDoesNotExist:
return getattr(self, field_name)
return getattr(self, field.attname)
def save(
self, force_insert=False, force_update=False, using=None, update_fields=None
):
"""
Save the current instance. Override this in a subclass if you want to
control the saving process.
The 'force_insert' and 'force_update' parameters can be used to insist
that the "save" must be an SQL insert or update (or equivalent for
non-SQL backends), respectively. Normally, they should not be set.
"""
self._prepare_related_fields_for_save(operation_name="save")
using = using or router.db_for_write(self.__class__, instance=self)
if force_insert and (force_update or update_fields):
raise ValueError("Cannot force both insert and updating in model saving.")
deferred_fields = self.get_deferred_fields()
if update_fields is not None:
# If update_fields is empty, skip the save. We do also check for
# no-op saves later on for inheritance cases. This bailout is
# still needed for skipping signal sending.
if not update_fields:
return
update_fields = frozenset(update_fields)
field_names = self._meta._non_pk_concrete_field_names
non_model_fields = update_fields.difference(field_names)
if non_model_fields:
raise ValueError(
"The following fields do not exist in this model, are m2m "
"fields, or are non-concrete fields: %s"
% ", ".join(non_model_fields)
)
# If saving to the same database, and this model is deferred, then
# automatically do an "update_fields" save on the loaded fields.
elif not force_insert and deferred_fields and using == self._state.db:
field_names = set()
for field in self._meta.concrete_fields:
if not field.primary_key and not hasattr(field, "through"):
field_names.add(field.attname)
loaded_fields = field_names.difference(deferred_fields)
if loaded_fields:
update_fields = frozenset(loaded_fields)
self.save_base(
using=using,
force_insert=force_insert,
force_update=force_update,
update_fields=update_fields,
)
save.alters_data = True
async def asave(
self, force_insert=False, force_update=False, using=None, update_fields=None
):
return await sync_to_async(self.save)(
force_insert=force_insert,
force_update=force_update,
using=using,
update_fields=update_fields,
)
asave.alters_data = True
def save_base(
self,
raw=False,
force_insert=False,
force_update=False,
using=None,
update_fields=None,
):
"""
Handle the parts of saving which should be done only once per save,
yet need to be done in raw saves, too. This includes some sanity
checks and signal sending.
The 'raw' argument is telling save_base not to save any parent
models and not to do any changes to the values before save. This
is used by fixture loading.
"""
using = using or router.db_for_write(self.__class__, instance=self)
assert not (force_insert and (force_update or update_fields))
assert update_fields is None or update_fields
cls = origin = self.__class__
# Skip proxies, but keep the origin as the proxy model.
if cls._meta.proxy:
cls = cls._meta.concrete_model
meta = cls._meta
if not meta.auto_created:
pre_save.send(
sender=origin,
instance=self,
raw=raw,
using=using,
update_fields=update_fields,
)
# A transaction isn't needed if one query is issued.
if meta.parents:
context_manager = transaction.atomic(using=using, savepoint=False)
else:
context_manager = transaction.mark_for_rollback_on_error(using=using)
with context_manager:
parent_inserted = False
if not raw:
parent_inserted = self._save_parents(cls, using, update_fields)
updated = self._save_table(
raw,
cls,
force_insert or parent_inserted,
force_update,
using,
update_fields,
)
# Store the database on which the object was saved
self._state.db = using
# Once saved, this is no longer a to-be-added instance.
self._state.adding = False
# Signal that the save is complete
if not meta.auto_created:
post_save.send(
sender=origin,
instance=self,
created=(not updated),
update_fields=update_fields,
raw=raw,
using=using,
)
save_base.alters_data = True
def _save_parents(self, cls, using, update_fields):
"""Save all the parents of cls using values from self."""
meta = cls._meta
inserted = False
for parent, field in meta.parents.items():
# Make sure the link fields are synced between parent and self.
if (
field
and getattr(self, parent._meta.pk.attname) is None
and getattr(self, field.attname) is not None
):
setattr(self, parent._meta.pk.attname, getattr(self, field.attname))
parent_inserted = self._save_parents(
cls=parent, using=using, update_fields=update_fields
)
updated = self._save_table(
cls=parent,
using=using,
update_fields=update_fields,
force_insert=parent_inserted,
)
if not updated:
inserted = True
# Set the parent's PK value to self.
if field:
setattr(self, field.attname, self._get_pk_val(parent._meta))
# Since we didn't have an instance of the parent handy set
# attname directly, bypassing the descriptor. Invalidate
# the related object cache, in case it's been accidentally
# populated. A fresh instance will be re-built from the
# database if necessary.
if field.is_cached(self):
field.delete_cached_value(self)
return inserted
def _save_table(
self,
raw=False,
cls=None,
force_insert=False,
force_update=False,
using=None,
update_fields=None,
):
"""
Do the heavy-lifting involved in saving. Update or insert the data
for a single table.
"""
meta = cls._meta
non_pks = [f for f in meta.local_concrete_fields if not f.primary_key]
if update_fields:
non_pks = [
f
for f in non_pks
if f.name in update_fields or f.attname in update_fields
]
pk_val = self._get_pk_val(meta)
if pk_val is None:
pk_val = meta.pk.get_pk_value_on_save(self)
setattr(self, meta.pk.attname, pk_val)
pk_set = pk_val is not None
if not pk_set and (force_update or update_fields):
raise ValueError("Cannot force an update in save() with no primary key.")
updated = False
# Skip an UPDATE when adding an instance and primary key has a default.
if (
not raw
and not force_insert
and self._state.adding
and meta.pk.default
and meta.pk.default is not NOT_PROVIDED
):
force_insert = True
# If possible, try an UPDATE. If that doesn't update anything, do an INSERT.
if pk_set and not force_insert:
base_qs = cls._base_manager.using(using)
values = [
(
f,
None,
(getattr(self, f.attname) if raw else f.pre_save(self, False)),
)
for f in non_pks
]
forced_update = update_fields or force_update
updated = self._do_update(
base_qs, using, pk_val, values, update_fields, forced_update
)
if force_update and not updated:
raise DatabaseError("Forced update did not affect any rows.")
if update_fields and not updated:
raise DatabaseError("Save with update_fields did not affect any rows.")
if not updated:
if meta.order_with_respect_to:
# If this is a model with an order_with_respect_to
# autopopulate the _order field
field = meta.order_with_respect_to
filter_args = field.get_filter_kwargs_for_object(self)
self._order = (
cls._base_manager.using(using)
.filter(**filter_args)
.aggregate(
_order__max=Coalesce(
ExpressionWrapper(
Max("_order") + Value(1), output_field=IntegerField()
),
Value(0),
),
)["_order__max"]
)
fields = meta.local_concrete_fields
if not pk_set:
fields = [f for f in fields if f is not meta.auto_field]
returning_fields = meta.db_returning_fields
results = self._do_insert(
cls._base_manager, using, fields, returning_fields, raw
)
if results:
for value, field in zip(results[0], returning_fields):
setattr(self, field.attname, value)
return updated
def _do_update(self, base_qs, using, pk_val, values, update_fields, forced_update):
"""
Try to update the model. Return True if the model was updated (if an
update query was done and a matching row was found in the DB).
"""
filtered = base_qs.filter(pk=pk_val)
if not values:
# We can end up here when saving a model in inheritance chain where
# update_fields doesn't target any field in current model. In that
# case we just say the update succeeded. Another case ending up here
# is a model with just PK - in that case check that the PK still
# exists.
return update_fields is not None or filtered.exists()
if self._meta.select_on_save and not forced_update:
return (
filtered.exists()
and
# It may happen that the object is deleted from the DB right after
# this check, causing the subsequent UPDATE to return zero matching
# rows. The same result can occur in some rare cases when the
# database returns zero despite the UPDATE being executed
# successfully (a row is matched and updated). In order to
# distinguish these two cases, the object's existence in the
# database is again checked for if the UPDATE query returns 0.
(filtered._update(values) > 0 or filtered.exists())
)
return filtered._update(values) > 0
def _do_insert(self, manager, using, fields, returning_fields, raw):
"""
Do an INSERT. If returning_fields is defined then this method should
return the newly created data for the model.
"""
return manager._insert(
[self],
fields=fields,
returning_fields=returning_fields,
using=using,
raw=raw,
)
def _prepare_related_fields_for_save(self, operation_name, fields=None):
# Ensure that a model instance without a PK hasn't been assigned to
# a ForeignKey, GenericForeignKey or OneToOneField on this model. If
# the field is nullable, allowing the save would result in silent data
# loss.
for field in self._meta.concrete_fields:
if fields and field not in fields:
continue
# If the related field isn't cached, then an instance hasn't been
# assigned and there's no need to worry about this check.
if field.is_relation and field.is_cached(self):
obj = getattr(self, field.name, None)
if not obj:
continue
# A pk may have been assigned manually to a model instance not
# saved to the database (or auto-generated in a case like
# UUIDField), but we allow the save to proceed and rely on the
# database to raise an IntegrityError if applicable. If
# constraints aren't supported by the database, there's the
# unavoidable risk of data corruption.
if obj.pk is None:
# Remove the object from a related instance cache.
if not field.remote_field.multiple:
field.remote_field.delete_cached_value(obj)
raise ValueError(
"%s() prohibited to prevent data loss due to unsaved "
"related object '%s'." % (operation_name, field.name)
)
elif getattr(self, field.attname) in field.empty_values:
# Set related object if it has been saved after an
# assignment.
setattr(self, field.name, obj)
# If the relationship's pk/to_field was changed, clear the
# cached relationship.
if getattr(obj, field.target_field.attname) != getattr(
self, field.attname
):
field.delete_cached_value(self)
# GenericForeignKeys are private.
for field in self._meta.private_fields:
if fields and field not in fields:
continue
if (
field.is_relation
and field.is_cached(self)
and hasattr(field, "fk_field")
):
obj = field.get_cached_value(self, default=None)
if obj and obj.pk is None:
raise ValueError(
f"{operation_name}() prohibited to prevent data loss due to "
f"unsaved related object '{field.name}'."
)
def delete(self, using=None, keep_parents=False):
if self.pk is None:
raise ValueError(
"%s object can't be deleted because its %s attribute is set "
"to None." % (self._meta.object_name, self._meta.pk.attname)
)
using = using or router.db_for_write(self.__class__, instance=self)
collector = Collector(using=using, origin=self)
collector.collect([self], keep_parents=keep_parents)
return collector.delete()
delete.alters_data = True
async def adelete(self, using=None, keep_parents=False):
return await sync_to_async(self.delete)(
using=using,
keep_parents=keep_parents,
)
adelete.alters_data = True
def _get_FIELD_display(self, field):
value = getattr(self, field.attname)
choices_dict = dict(make_hashable(field.flatchoices))
# force_str() to coerce lazy strings.
return force_str(
choices_dict.get(make_hashable(value), value), strings_only=True
)
def _get_next_or_previous_by_FIELD(self, field, is_next, **kwargs):
if not self.pk:
raise ValueError("get_next/get_previous cannot be used on unsaved objects.")
op = "gt" if is_next else "lt"
order = "" if is_next else "-"
param = getattr(self, field.attname)
q = Q.create([(field.name, param), (f"pk__{op}", self.pk)], connector=Q.AND)
q = Q.create([q, (f"{field.name}__{op}", param)], connector=Q.OR)
qs = (
self.__class__._default_manager.using(self._state.db)
.filter(**kwargs)
.filter(q)
.order_by("%s%s" % (order, field.name), "%spk" % order)
)
try:
return qs[0]
except IndexError:
raise self.DoesNotExist(
"%s matching query does not exist." % self.__class__._meta.object_name
)
def _get_next_or_previous_in_order(self, is_next):
cachename = "__%s_order_cache" % is_next
if not hasattr(self, cachename):
op = "gt" if is_next else "lt"
order = "_order" if is_next else "-_order"
order_field = self._meta.order_with_respect_to
filter_args = order_field.get_filter_kwargs_for_object(self)
obj = (
self.__class__._default_manager.filter(**filter_args)
.filter(
**{
"_order__%s"
% op: self.__class__._default_manager.values("_order").filter(
**{self._meta.pk.name: self.pk}
)
}
)
.order_by(order)[:1]
.get()
)
setattr(self, cachename, obj)
return getattr(self, cachename)
def _get_field_value_map(self, meta, exclude=None):
if exclude is None:
exclude = set()
meta = meta or self._meta
return {
field.name: Value(getattr(self, field.attname), field)
for field in meta.local_concrete_fields
if field.name not in exclude
}
def prepare_database_save(self, field):
if self.pk is None:
raise ValueError(
"Unsaved model instance %r cannot be used in an ORM query." % self
)
return getattr(self, field.remote_field.get_related_field().attname)
def clean(self):
"""
Hook for doing any extra model-wide validation after clean() has been
called on every field by self.clean_fields. Any ValidationError raised
by this method will not be associated with a particular field; it will
have a special-case association with the field defined by NON_FIELD_ERRORS.
"""
pass
def validate_unique(self, exclude=None):
"""
Check unique constraints on the model and raise ValidationError if any
failed.
"""
unique_checks, date_checks = self._get_unique_checks(exclude=exclude)
errors = self._perform_unique_checks(unique_checks)
date_errors = self._perform_date_checks(date_checks)
for k, v in date_errors.items():
errors.setdefault(k, []).extend(v)
if errors:
raise ValidationError(errors)
def _get_unique_checks(self, exclude=None, include_meta_constraints=False):
"""
Return a list of checks to perform. Since validate_unique() could be
called from a ModelForm, some fields may have been excluded; we can't
perform a unique check on a model that is missing fields involved
in that check. Fields that did not validate should also be excluded,
but they need to be passed in via the exclude argument.
"""
if exclude is None:
exclude = set()
unique_checks = []
unique_togethers = [(self.__class__, self._meta.unique_together)]
constraints = []
if include_meta_constraints:
constraints = [(self.__class__, self._meta.total_unique_constraints)]
for parent_class in self._meta.get_parent_list():
if parent_class._meta.unique_together:
unique_togethers.append(
(parent_class, parent_class._meta.unique_together)
)
if include_meta_constraints and parent_class._meta.total_unique_constraints:
constraints.append(
(parent_class, parent_class._meta.total_unique_constraints)
)
for model_class, unique_together in unique_togethers:
for check in unique_together:
if not any(name in exclude for name in check):
# Add the check if the field isn't excluded.
unique_checks.append((model_class, tuple(check)))
if include_meta_constraints:
for model_class, model_constraints in constraints:
for constraint in model_constraints:
if not any(name in exclude for name in constraint.fields):
unique_checks.append((model_class, constraint.fields))
# These are checks for the unique_for_<date/year/month>.
date_checks = []
# Gather a list of checks for fields declared as unique and add them to
# the list of checks.
fields_with_class = [(self.__class__, self._meta.local_fields)]
for parent_class in self._meta.get_parent_list():
fields_with_class.append((parent_class, parent_class._meta.local_fields))
for model_class, fields in fields_with_class:
for f in fields:
name = f.name
if name in exclude:
continue
if f.unique:
unique_checks.append((model_class, (name,)))
if f.unique_for_date and f.unique_for_date not in exclude:
date_checks.append((model_class, "date", name, f.unique_for_date))
if f.unique_for_year and f.unique_for_year not in exclude:
date_checks.append((model_class, "year", name, f.unique_for_year))
if f.unique_for_month and f.unique_for_month not in exclude:
date_checks.append((model_class, "month", name, f.unique_for_month))
return unique_checks, date_checks
def _perform_unique_checks(self, unique_checks):
errors = {}
for model_class, unique_check in unique_checks:
# Try to look up an existing object with the same values as this
# object's values for all the unique field.
lookup_kwargs = {}
for field_name in unique_check:
f = self._meta.get_field(field_name)
lookup_value = getattr(self, f.attname)
# TODO: Handle multiple backends with different feature flags.
if lookup_value is None or (
lookup_value == ""
and connection.features.interprets_empty_strings_as_nulls
):
# no value, skip the lookup
continue
if f.primary_key and not self._state.adding:
# no need to check for unique primary key when editing
continue
lookup_kwargs[str(field_name)] = lookup_value
# some fields were skipped, no reason to do the check
if len(unique_check) != len(lookup_kwargs):
continue
qs = model_class._default_manager.filter(**lookup_kwargs)
# Exclude the current object from the query if we are editing an
# instance (as opposed to creating a new one)
# Note that we need to use the pk as defined by model_class, not
# self.pk. These can be different fields because model inheritance
# allows single model to have effectively multiple primary keys.
# Refs #17615.
model_class_pk = self._get_pk_val(model_class._meta)
if not self._state.adding and model_class_pk is not None:
qs = qs.exclude(pk=model_class_pk)
if qs.exists():
if len(unique_check) == 1:
key = unique_check[0]
else:
key = NON_FIELD_ERRORS
errors.setdefault(key, []).append(
self.unique_error_message(model_class, unique_check)
)
return errors
def _perform_date_checks(self, date_checks):
errors = {}
for model_class, lookup_type, field, unique_for in date_checks:
lookup_kwargs = {}
# there's a ticket to add a date lookup, we can remove this special
# case if that makes it's way in
date = getattr(self, unique_for)
if date is None:
continue
if lookup_type == "date":
lookup_kwargs["%s__day" % unique_for] = date.day
lookup_kwargs["%s__month" % unique_for] = date.month
lookup_kwargs["%s__year" % unique_for] = date.year
else:
lookup_kwargs["%s__%s" % (unique_for, lookup_type)] = getattr(
date, lookup_type
)
lookup_kwargs[field] = getattr(self, field)
qs = model_class._default_manager.filter(**lookup_kwargs)
# Exclude the current object from the query if we are editing an
# instance (as opposed to creating a new one)
if not self._state.adding and self.pk is not None:
qs = qs.exclude(pk=self.pk)
if qs.exists():
errors.setdefault(field, []).append(
self.date_error_message(lookup_type, field, unique_for)
)
return errors
def date_error_message(self, lookup_type, field_name, unique_for):
opts = self._meta
field = opts.get_field(field_name)
return ValidationError(
message=field.error_messages["unique_for_date"],
code="unique_for_date",
params={
"model": self,
"model_name": capfirst(opts.verbose_name),
"lookup_type": lookup_type,
"field": field_name,
"field_label": capfirst(field.verbose_name),
"date_field": unique_for,
"date_field_label": capfirst(opts.get_field(unique_for).verbose_name),
},
)
def unique_error_message(self, model_class, unique_check):
opts = model_class._meta
params = {
"model": self,
"model_class": model_class,
"model_name": capfirst(opts.verbose_name),
"unique_check": unique_check,
}
# A unique field
if len(unique_check) == 1:
field = opts.get_field(unique_check[0])
params["field_label"] = capfirst(field.verbose_name)
return ValidationError(
message=field.error_messages["unique"],
code="unique",
params=params,
)
# unique_together
else:
field_labels = [
capfirst(opts.get_field(f).verbose_name) for f in unique_check
]
params["field_labels"] = get_text_list(field_labels, _("and"))
return ValidationError(
message=_("%(model_name)s with this %(field_labels)s already exists."),
code="unique_together",
params=params,
)
def get_constraints(self):
constraints = [(self.__class__, self._meta.constraints)]
for parent_class in self._meta.get_parent_list():
if parent_class._meta.constraints:
constraints.append((parent_class, parent_class._meta.constraints))
return constraints
def validate_constraints(self, exclude=None):
constraints = self.get_constraints()
using = router.db_for_write(self.__class__, instance=self)
errors = {}
for model_class, model_constraints in constraints:
for constraint in model_constraints:
try:
constraint.validate(model_class, self, exclude=exclude, using=using)
except ValidationError as e:
if (
getattr(e, "code", None) == "unique"
and len(constraint.fields) == 1
):
errors.setdefault(constraint.fields[0], []).append(e)
else:
errors = e.update_error_dict(errors)
if errors:
raise ValidationError(errors)
def full_clean(self, exclude=None, validate_unique=True, validate_constraints=True):
"""
Call clean_fields(), clean(), validate_unique(), and
validate_constraints() on the model. Raise a ValidationError for any
errors that occur.
"""
errors = {}
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
try:
self.clean_fields(exclude=exclude)
except ValidationError as e:
errors = e.update_error_dict(errors)
# Form.clean() is run even if other validation fails, so do the
# same with Model.clean() for consistency.
try:
self.clean()
except ValidationError as e:
errors = e.update_error_dict(errors)
# Run unique checks, but only for fields that passed validation.
if validate_unique:
for name in errors:
if name != NON_FIELD_ERRORS and name not in exclude:
exclude.add(name)
try:
self.validate_unique(exclude=exclude)
except ValidationError as e:
errors = e.update_error_dict(errors)
# Run constraints checks, but only for fields that passed validation.
if validate_constraints:
for name in errors:
if name != NON_FIELD_ERRORS and name not in exclude:
exclude.add(name)
try:
self.validate_constraints(exclude=exclude)
except ValidationError as e:
errors = e.update_error_dict(errors)
if errors:
raise ValidationError(errors)
def clean_fields(self, exclude=None):
"""
Clean all fields and raise a ValidationError containing a dict
of all validation errors if any occur.
"""
if exclude is None:
exclude = set()
errors = {}
for f in self._meta.fields:
if f.name in exclude:
continue
# Skip validation for empty fields with blank=True. The developer
# is responsible for making sure they have a valid value.
raw_value = getattr(self, f.attname)
if f.blank and raw_value in f.empty_values:
continue
try:
setattr(self, f.attname, f.clean(raw_value, self))
except ValidationError as e:
errors[f.name] = e.error_list
if errors:
raise ValidationError(errors)
@classmethod
def check(cls, **kwargs):
errors = [
*cls._check_swappable(),
*cls._check_model(),
*cls._check_managers(**kwargs),
]
if not cls._meta.swapped:
databases = kwargs.get("databases") or []
errors += [
*cls._check_fields(**kwargs),
*cls._check_m2m_through_same_relationship(),
*cls._check_long_column_names(databases),
]
clash_errors = (
*cls._check_id_field(),
*cls._check_field_name_clashes(),
*cls._check_model_name_db_lookup_clashes(),
*cls._check_property_name_related_field_accessor_clashes(),
*cls._check_single_primary_key(),
)
errors.extend(clash_errors)
# If there are field name clashes, hide consequent column name
# clashes.
if not clash_errors:
errors.extend(cls._check_column_name_clashes())
errors += [
*cls._check_index_together(),
*cls._check_unique_together(),
*cls._check_indexes(databases),
*cls._check_ordering(),
*cls._check_constraints(databases),
*cls._check_default_pk(),
*cls._check_db_table_comment(databases),
]
return errors
@classmethod
def _check_default_pk(cls):
if (
not cls._meta.abstract
and cls._meta.pk.auto_created
and
# Inherited PKs are checked in parents models.
not (
isinstance(cls._meta.pk, OneToOneField)
and cls._meta.pk.remote_field.parent_link
)
and not settings.is_overridden("DEFAULT_AUTO_FIELD")
and cls._meta.app_config
and not cls._meta.app_config._is_default_auto_field_overridden
):
return [
checks.Warning(
f"Auto-created primary key used when not defining a "
f"primary key type, by default "
f"'{settings.DEFAULT_AUTO_FIELD}'.",
hint=(
f"Configure the DEFAULT_AUTO_FIELD setting or the "
f"{cls._meta.app_config.__class__.__qualname__}."
f"default_auto_field attribute to point to a subclass "
f"of AutoField, e.g. 'django.db.models.BigAutoField'."
),
obj=cls,
id="models.W042",
),
]
return []
@classmethod
def _check_db_table_comment(cls, databases):
if not cls._meta.db_table_comment:
return []
errors = []
for db in databases:
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
if not (
connection.features.supports_comments
or "supports_comments" in cls._meta.required_db_features
):
errors.append(
checks.Warning(
f"{connection.display_name} does not support comments on "
f"tables (db_table_comment).",
obj=cls,
id="models.W046",
)
)
return errors
@classmethod
def _check_swappable(cls):
"""Check if the swapped model exists."""
errors = []
if cls._meta.swapped:
try:
apps.get_model(cls._meta.swapped)
except ValueError:
errors.append(
checks.Error(
"'%s' is not of the form 'app_label.app_name'."
% cls._meta.swappable,
id="models.E001",
)
)
except LookupError:
app_label, model_name = cls._meta.swapped.split(".")
errors.append(
checks.Error(
"'%s' references '%s.%s', which has not been "
"installed, or is abstract."
% (cls._meta.swappable, app_label, model_name),
id="models.E002",
)
)
return errors
@classmethod
def _check_model(cls):
errors = []
if cls._meta.proxy:
if cls._meta.local_fields or cls._meta.local_many_to_many:
errors.append(
checks.Error(
"Proxy model '%s' contains model fields." % cls.__name__,
id="models.E017",
)
)
return errors
@classmethod
def _check_managers(cls, **kwargs):
"""Perform all manager checks."""
errors = []
for manager in cls._meta.managers:
errors.extend(manager.check(**kwargs))
return errors
@classmethod
def _check_fields(cls, **kwargs):
"""Perform all field checks."""
errors = []
for field in cls._meta.local_fields:
errors.extend(field.check(**kwargs))
for field in cls._meta.local_many_to_many:
errors.extend(field.check(from_model=cls, **kwargs))
return errors
@classmethod
def _check_m2m_through_same_relationship(cls):
"""Check if no relationship model is used by more than one m2m field."""
errors = []
seen_intermediary_signatures = []
fields = cls._meta.local_many_to_many
# Skip when the target model wasn't found.
fields = (f for f in fields if isinstance(f.remote_field.model, ModelBase))
# Skip when the relationship model wasn't found.
fields = (f for f in fields if isinstance(f.remote_field.through, ModelBase))
for f in fields:
signature = (
f.remote_field.model,
cls,
f.remote_field.through,
f.remote_field.through_fields,
)
if signature in seen_intermediary_signatures:
errors.append(
checks.Error(
"The model has two identical many-to-many relations "
"through the intermediate model '%s'."
% f.remote_field.through._meta.label,
obj=cls,
id="models.E003",
)
)
else:
seen_intermediary_signatures.append(signature)
return errors
@classmethod
def _check_id_field(cls):
"""Check if `id` field is a primary key."""
fields = [
f for f in cls._meta.local_fields if f.name == "id" and f != cls._meta.pk
]
# fields is empty or consists of the invalid "id" field
if fields and not fields[0].primary_key and cls._meta.pk.name == "id":
return [
checks.Error(
"'id' can only be used as a field name if the field also "
"sets 'primary_key=True'.",
obj=cls,
id="models.E004",
)
]
else:
return []
@classmethod
def _check_field_name_clashes(cls):
"""Forbid field shadowing in multi-table inheritance."""
errors = []
used_fields = {} # name or attname -> field
# Check that multi-inheritance doesn't cause field name shadowing.
for parent in cls._meta.get_parent_list():
for f in parent._meta.local_fields:
clash = used_fields.get(f.name) or used_fields.get(f.attname) or None
if clash:
errors.append(
checks.Error(
"The field '%s' from parent model "
"'%s' clashes with the field '%s' "
"from parent model '%s'."
% (clash.name, clash.model._meta, f.name, f.model._meta),
obj=cls,
id="models.E005",
)
)
used_fields[f.name] = f
used_fields[f.attname] = f
# Check that fields defined in the model don't clash with fields from
# parents, including auto-generated fields like multi-table inheritance
# child accessors.
for parent in cls._meta.get_parent_list():
for f in parent._meta.get_fields():
if f not in used_fields:
used_fields[f.name] = f
for f in cls._meta.local_fields:
clash = used_fields.get(f.name) or used_fields.get(f.attname) or None
# Note that we may detect clash between user-defined non-unique
# field "id" and automatically added unique field "id", both
# defined at the same model. This special case is considered in
# _check_id_field and here we ignore it.
id_conflict = (
f.name == "id" and clash and clash.name == "id" and clash.model == cls
)
if clash and not id_conflict:
errors.append(
checks.Error(
"The field '%s' clashes with the field '%s' "
"from model '%s'." % (f.name, clash.name, clash.model._meta),
obj=f,
id="models.E006",
)
)
used_fields[f.name] = f
used_fields[f.attname] = f
return errors
@classmethod
def _check_column_name_clashes(cls):
# Store a list of column names which have already been used by other fields.
used_column_names = []
errors = []
for f in cls._meta.local_fields:
_, column_name = f.get_attname_column()
# Ensure the column name is not already in use.
if column_name and column_name in used_column_names:
errors.append(
checks.Error(
"Field '%s' has column name '%s' that is used by "
"another field." % (f.name, column_name),
hint="Specify a 'db_column' for the field.",
obj=cls,
id="models.E007",
)
)
else:
used_column_names.append(column_name)
return errors
@classmethod
def _check_model_name_db_lookup_clashes(cls):
errors = []
model_name = cls.__name__
if model_name.startswith("_") or model_name.endswith("_"):
errors.append(
checks.Error(
"The model name '%s' cannot start or end with an underscore "
"as it collides with the query lookup syntax." % model_name,
obj=cls,
id="models.E023",
)
)
elif LOOKUP_SEP in model_name:
errors.append(
checks.Error(
"The model name '%s' cannot contain double underscores as "
"it collides with the query lookup syntax." % model_name,
obj=cls,
id="models.E024",
)
)
return errors
@classmethod
def _check_property_name_related_field_accessor_clashes(cls):
errors = []
property_names = cls._meta._property_names
related_field_accessors = (
f.get_attname()
for f in cls._meta._get_fields(reverse=False)
if f.is_relation and f.related_model is not None
)
for accessor in related_field_accessors:
if accessor in property_names:
errors.append(
checks.Error(
"The property '%s' clashes with a related field "
"accessor." % accessor,
obj=cls,
id="models.E025",
)
)
return errors
@classmethod
def _check_single_primary_key(cls):
errors = []
if sum(1 for f in cls._meta.local_fields if f.primary_key) > 1:
errors.append(
checks.Error(
"The model cannot have more than one field with "
"'primary_key=True'.",
obj=cls,
id="models.E026",
)
)
return errors
# RemovedInDjango51Warning.
@classmethod
def _check_index_together(cls):
"""Check the value of "index_together" option."""
if not isinstance(cls._meta.index_together, (tuple, list)):
return [
checks.Error(
"'index_together' must be a list or tuple.",
obj=cls,
id="models.E008",
)
]
elif any(
not isinstance(fields, (tuple, list)) for fields in cls._meta.index_together
):
return [
checks.Error(
"All 'index_together' elements must be lists or tuples.",
obj=cls,
id="models.E009",
)
]
else:
errors = []
for fields in cls._meta.index_together:
errors.extend(cls._check_local_fields(fields, "index_together"))
return errors
@classmethod
def _check_unique_together(cls):
"""Check the value of "unique_together" option."""
if not isinstance(cls._meta.unique_together, (tuple, list)):
return [
checks.Error(
"'unique_together' must be a list or tuple.",
obj=cls,
id="models.E010",
)
]
elif any(
not isinstance(fields, (tuple, list))
for fields in cls._meta.unique_together
):
return [
checks.Error(
"All 'unique_together' elements must be lists or tuples.",
obj=cls,
id="models.E011",
)
]
else:
errors = []
for fields in cls._meta.unique_together:
errors.extend(cls._check_local_fields(fields, "unique_together"))
return errors
@classmethod
def _check_indexes(cls, databases):
"""Check fields, names, and conditions of indexes."""
errors = []
references = set()
for index in cls._meta.indexes:
# Index name can't start with an underscore or a number, restricted
# for cross-database compatibility with Oracle.
if index.name[0] == "_" or index.name[0].isdigit():
errors.append(
checks.Error(
"The index name '%s' cannot start with an underscore "
"or a number." % index.name,
obj=cls,
id="models.E033",
),
)
if len(index.name) > index.max_name_length:
errors.append(
checks.Error(
"The index name '%s' cannot be longer than %d "
"characters." % (index.name, index.max_name_length),
obj=cls,
id="models.E034",
),
)
if index.contains_expressions:
for expression in index.expressions:
references.update(
ref[0] for ref in cls._get_expr_references(expression)
)
for db in databases:
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
if not (
connection.features.supports_partial_indexes
or "supports_partial_indexes" in cls._meta.required_db_features
) and any(index.condition is not None for index in cls._meta.indexes):
errors.append(
checks.Warning(
"%s does not support indexes with conditions."
% connection.display_name,
hint=(
"Conditions will be ignored. Silence this warning "
"if you don't care about it."
),
obj=cls,
id="models.W037",
)
)
if not (
connection.features.supports_covering_indexes
or "supports_covering_indexes" in cls._meta.required_db_features
) and any(index.include for index in cls._meta.indexes):
errors.append(
checks.Warning(
"%s does not support indexes with non-key columns."
% connection.display_name,
hint=(
"Non-key columns will be ignored. Silence this "
"warning if you don't care about it."
),
obj=cls,
id="models.W040",
)
)
if not (
connection.features.supports_expression_indexes
or "supports_expression_indexes" in cls._meta.required_db_features
) and any(index.contains_expressions for index in cls._meta.indexes):
errors.append(
checks.Warning(
"%s does not support indexes on expressions."
% connection.display_name,
hint=(
"An index won't be created. Silence this warning "
"if you don't care about it."
),
obj=cls,
id="models.W043",
)
)
fields = [
field for index in cls._meta.indexes for field, _ in index.fields_orders
]
fields += [include for index in cls._meta.indexes for include in index.include]
fields += references
errors.extend(cls._check_local_fields(fields, "indexes"))
return errors
@classmethod
def _check_local_fields(cls, fields, option):
from django.db import models
# In order to avoid hitting the relation tree prematurely, we use our
# own fields_map instead of using get_field()
forward_fields_map = {}
for field in cls._meta._get_fields(reverse=False):
forward_fields_map[field.name] = field
if hasattr(field, "attname"):
forward_fields_map[field.attname] = field
errors = []
for field_name in fields:
try:
field = forward_fields_map[field_name]
except KeyError:
errors.append(
checks.Error(
"'%s' refers to the nonexistent field '%s'."
% (
option,
field_name,
),
obj=cls,
id="models.E012",
)
)
else:
if isinstance(field.remote_field, models.ManyToManyRel):
errors.append(
checks.Error(
"'%s' refers to a ManyToManyField '%s', but "
"ManyToManyFields are not permitted in '%s'."
% (
option,
field_name,
option,
),
obj=cls,
id="models.E013",
)
)
elif field not in cls._meta.local_fields:
errors.append(
checks.Error(
"'%s' refers to field '%s' which is not local to model "
"'%s'." % (option, field_name, cls._meta.object_name),
hint="This issue may be caused by multi-table inheritance.",
obj=cls,
id="models.E016",
)
)
return errors
@classmethod
def _check_ordering(cls):
"""
Check "ordering" option -- is it a list of strings and do all fields
exist?
"""
if cls._meta._ordering_clash:
return [
checks.Error(
"'ordering' and 'order_with_respect_to' cannot be used together.",
obj=cls,
id="models.E021",
),
]
if cls._meta.order_with_respect_to or not cls._meta.ordering:
return []
if not isinstance(cls._meta.ordering, (list, tuple)):
return [
checks.Error(
"'ordering' must be a tuple or list (even if you want to order by "
"only one field).",
obj=cls,
id="models.E014",
)
]
errors = []
fields = cls._meta.ordering
# Skip expressions and '?' fields.
fields = (f for f in fields if isinstance(f, str) and f != "?")
# Convert "-field" to "field".
fields = ((f[1:] if f.startswith("-") else f) for f in fields)
# Separate related fields and non-related fields.
_fields = []
related_fields = []
for f in fields:
if LOOKUP_SEP in f:
related_fields.append(f)
else:
_fields.append(f)
fields = _fields
# Check related fields.
for field in related_fields:
_cls = cls
fld = None
for part in field.split(LOOKUP_SEP):
try:
# pk is an alias that won't be found by opts.get_field.
if part == "pk":
fld = _cls._meta.pk
else:
fld = _cls._meta.get_field(part)
if fld.is_relation:
_cls = fld.path_infos[-1].to_opts.model
else:
_cls = None
except (FieldDoesNotExist, AttributeError):
if fld is None or (
fld.get_transform(part) is None and fld.get_lookup(part) is None
):
errors.append(
checks.Error(
"'ordering' refers to the nonexistent field, "
"related field, or lookup '%s'." % field,
obj=cls,
id="models.E015",
)
)
# Skip ordering on pk. This is always a valid order_by field
# but is an alias and therefore won't be found by opts.get_field.
fields = {f for f in fields if f != "pk"}
# Check for invalid or nonexistent fields in ordering.
invalid_fields = []
# Any field name that is not present in field_names does not exist.
# Also, ordering by m2m fields is not allowed.
opts = cls._meta
valid_fields = set(
chain.from_iterable(
(f.name, f.attname)
if not (f.auto_created and not f.concrete)
else (f.field.related_query_name(),)
for f in chain(opts.fields, opts.related_objects)
)
)
invalid_fields.extend(fields - valid_fields)
for invalid_field in invalid_fields:
errors.append(
checks.Error(
"'ordering' refers to the nonexistent field, related "
"field, or lookup '%s'." % invalid_field,
obj=cls,
id="models.E015",
)
)
return errors
@classmethod
def _check_long_column_names(cls, databases):
"""
Check that any auto-generated column names are shorter than the limits
for each database in which the model will be created.
"""
if not databases:
return []
errors = []
allowed_len = None
db_alias = None
# Find the minimum max allowed length among all specified db_aliases.
for db in databases:
# skip databases where the model won't be created
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
max_name_length = connection.ops.max_name_length()
if max_name_length is None or connection.features.truncates_names:
continue
else:
if allowed_len is None:
allowed_len = max_name_length
db_alias = db
elif max_name_length < allowed_len:
allowed_len = max_name_length
db_alias = db
if allowed_len is None:
return errors
for f in cls._meta.local_fields:
_, column_name = f.get_attname_column()
# Check if auto-generated name for the field is too long
# for the database.
if (
f.db_column is None
and column_name is not None
and len(column_name) > allowed_len
):
errors.append(
checks.Error(
'Autogenerated column name too long for field "%s". '
'Maximum length is "%s" for database "%s".'
% (column_name, allowed_len, db_alias),
hint="Set the column name manually using 'db_column'.",
obj=cls,
id="models.E018",
)
)
for f in cls._meta.local_many_to_many:
# Skip nonexistent models.
if isinstance(f.remote_field.through, str):
continue
# Check if auto-generated name for the M2M field is too long
# for the database.
for m2m in f.remote_field.through._meta.local_fields:
_, rel_name = m2m.get_attname_column()
if (
m2m.db_column is None
and rel_name is not None
and len(rel_name) > allowed_len
):
errors.append(
checks.Error(
"Autogenerated column name too long for M2M field "
'"%s". Maximum length is "%s" for database "%s".'
% (rel_name, allowed_len, db_alias),
hint=(
"Use 'through' to create a separate model for "
"M2M and then set column_name using 'db_column'."
),
obj=cls,
id="models.E019",
)
)
return errors
@classmethod
def _get_expr_references(cls, expr):
if isinstance(expr, Q):
for child in expr.children:
if isinstance(child, tuple):
lookup, value = child
yield tuple(lookup.split(LOOKUP_SEP))
yield from cls._get_expr_references(value)
else:
yield from cls._get_expr_references(child)
elif isinstance(expr, F):
yield tuple(expr.name.split(LOOKUP_SEP))
elif hasattr(expr, "get_source_expressions"):
for src_expr in expr.get_source_expressions():
yield from cls._get_expr_references(src_expr)
@classmethod
def _check_constraints(cls, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
if not (
connection.features.supports_table_check_constraints
or "supports_table_check_constraints" in cls._meta.required_db_features
) and any(
isinstance(constraint, CheckConstraint)
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
"%s does not support check constraints."
% connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id="models.W027",
)
)
if not (
connection.features.supports_partial_indexes
or "supports_partial_indexes" in cls._meta.required_db_features
) and any(
isinstance(constraint, UniqueConstraint)
and constraint.condition is not None
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
"%s does not support unique constraints with "
"conditions." % connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id="models.W036",
)
)
if not (
connection.features.supports_deferrable_unique_constraints
or "supports_deferrable_unique_constraints"
in cls._meta.required_db_features
) and any(
isinstance(constraint, UniqueConstraint)
and constraint.deferrable is not None
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
"%s does not support deferrable unique constraints."
% connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id="models.W038",
)
)
if not (
connection.features.supports_covering_indexes
or "supports_covering_indexes" in cls._meta.required_db_features
) and any(
isinstance(constraint, UniqueConstraint) and constraint.include
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
"%s does not support unique constraints with non-key "
"columns." % connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id="models.W039",
)
)
if not (
connection.features.supports_expression_indexes
or "supports_expression_indexes" in cls._meta.required_db_features
) and any(
isinstance(constraint, UniqueConstraint)
and constraint.contains_expressions
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
"%s does not support unique constraints on "
"expressions." % connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id="models.W044",
)
)
fields = set(
chain.from_iterable(
(*constraint.fields, *constraint.include)
for constraint in cls._meta.constraints
if isinstance(constraint, UniqueConstraint)
)
)
references = set()
for constraint in cls._meta.constraints:
if isinstance(constraint, UniqueConstraint):
if (
connection.features.supports_partial_indexes
or "supports_partial_indexes"
not in cls._meta.required_db_features
) and isinstance(constraint.condition, Q):
references.update(
cls._get_expr_references(constraint.condition)
)
if (
connection.features.supports_expression_indexes
or "supports_expression_indexes"
not in cls._meta.required_db_features
) and constraint.contains_expressions:
for expression in constraint.expressions:
references.update(cls._get_expr_references(expression))
elif isinstance(constraint, CheckConstraint):
if (
connection.features.supports_table_check_constraints
or "supports_table_check_constraints"
not in cls._meta.required_db_features
):
if isinstance(constraint.check, Q):
references.update(
cls._get_expr_references(constraint.check)
)
if any(
isinstance(expr, RawSQL)
for expr in constraint.check.flatten()
):
errors.append(
checks.Warning(
f"Check constraint {constraint.name!r} contains "
f"RawSQL() expression and won't be validated "
f"during the model full_clean().",
hint=(
"Silence this warning if you don't care about "
"it."
),
obj=cls,
id="models.W045",
),
)
for field_name, *lookups in references:
# pk is an alias that won't be found by opts.get_field.
if field_name != "pk":
fields.add(field_name)
if not lookups:
# If it has no lookups it cannot result in a JOIN.
continue
try:
if field_name == "pk":
field = cls._meta.pk
else:
field = cls._meta.get_field(field_name)
if not field.is_relation or field.many_to_many or field.one_to_many:
continue
except FieldDoesNotExist:
continue
# JOIN must happen at the first lookup.
first_lookup = lookups[0]
if (
hasattr(field, "get_transform")
and hasattr(field, "get_lookup")
and field.get_transform(first_lookup) is None
and field.get_lookup(first_lookup) is None
):
errors.append(
checks.Error(
"'constraints' refers to the joined field '%s'."
% LOOKUP_SEP.join([field_name] + lookups),
obj=cls,
id="models.E041",
)
)
errors.extend(cls._check_local_fields(fields, "constraints"))
return errors
############################################
# HELPER FUNCTIONS (CURRIED MODEL METHODS) #
############################################
# ORDERING METHODS #########################
def method_set_order(self, ordered_obj, id_list, using=None):
order_wrt = ordered_obj._meta.order_with_respect_to
filter_args = order_wrt.get_forward_related_filter(self)
ordered_obj.objects.db_manager(using).filter(**filter_args).bulk_update(
[ordered_obj(pk=pk, _order=order) for order, pk in enumerate(id_list)],
["_order"],
)
def method_get_order(self, ordered_obj):
order_wrt = ordered_obj._meta.order_with_respect_to
filter_args = order_wrt.get_forward_related_filter(self)
pk_name = ordered_obj._meta.pk.name
return ordered_obj.objects.filter(**filter_args).values_list(pk_name, flat=True)
def make_foreign_order_accessors(model, related_model):
setattr(
related_model,
"get_%s_order" % model.__name__.lower(),
partialmethod(method_get_order, model),
)
setattr(
related_model,
"set_%s_order" % model.__name__.lower(),
partialmethod(method_set_order, model),
)
########
# MISC #
########
def model_unpickle(model_id):
"""Used to unpickle Model subclasses with deferred fields."""
if isinstance(model_id, tuple):
model = apps.get_model(*model_id)
else:
# Backwards compat - the model was cached directly in earlier versions.
model = model_id
return model.__new__(model)
model_unpickle.__safe_for_unpickle__ = True
|
castiel248/Convert
|
Lib/site-packages/django/db/models/base.py
|
Python
|
mit
| 100,332 |
"""
Constants used across the ORM in general.
"""
from enum import Enum
# Separator used to split filter strings apart.
LOOKUP_SEP = "__"
class OnConflict(Enum):
IGNORE = "ignore"
UPDATE = "update"
|
castiel248/Convert
|
Lib/site-packages/django/db/models/constants.py
|
Python
|
mit
| 209 |
from enum import Enum
from django.core.exceptions import FieldError, ValidationError
from django.db import connections
from django.db.models.expressions import Exists, ExpressionList, F, OrderBy
from django.db.models.indexes import IndexExpression
from django.db.models.lookups import Exact
from django.db.models.query_utils import Q
from django.db.models.sql.query import Query
from django.db.utils import DEFAULT_DB_ALIAS
from django.utils.translation import gettext_lazy as _
__all__ = ["BaseConstraint", "CheckConstraint", "Deferrable", "UniqueConstraint"]
class BaseConstraint:
default_violation_error_message = _("Constraint “%(name)s” is violated.")
violation_error_message = None
def __init__(self, name, violation_error_message=None):
self.name = name
if violation_error_message is not None:
self.violation_error_message = violation_error_message
else:
self.violation_error_message = self.default_violation_error_message
@property
def contains_expressions(self):
return False
def constraint_sql(self, model, schema_editor):
raise NotImplementedError("This method must be implemented by a subclass.")
def create_sql(self, model, schema_editor):
raise NotImplementedError("This method must be implemented by a subclass.")
def remove_sql(self, model, schema_editor):
raise NotImplementedError("This method must be implemented by a subclass.")
def validate(self, model, instance, exclude=None, using=DEFAULT_DB_ALIAS):
raise NotImplementedError("This method must be implemented by a subclass.")
def get_violation_error_message(self):
return self.violation_error_message % {"name": self.name}
def deconstruct(self):
path = "%s.%s" % (self.__class__.__module__, self.__class__.__name__)
path = path.replace("django.db.models.constraints", "django.db.models")
kwargs = {"name": self.name}
if (
self.violation_error_message is not None
and self.violation_error_message != self.default_violation_error_message
):
kwargs["violation_error_message"] = self.violation_error_message
return (path, (), kwargs)
def clone(self):
_, args, kwargs = self.deconstruct()
return self.__class__(*args, **kwargs)
class CheckConstraint(BaseConstraint):
def __init__(self, *, check, name, violation_error_message=None):
self.check = check
if not getattr(check, "conditional", False):
raise TypeError(
"CheckConstraint.check must be a Q instance or boolean expression."
)
super().__init__(name, violation_error_message=violation_error_message)
def _get_check_sql(self, model, schema_editor):
query = Query(model=model, alias_cols=False)
where = query.build_where(self.check)
compiler = query.get_compiler(connection=schema_editor.connection)
sql, params = where.as_sql(compiler, schema_editor.connection)
return sql % tuple(schema_editor.quote_value(p) for p in params)
def constraint_sql(self, model, schema_editor):
check = self._get_check_sql(model, schema_editor)
return schema_editor._check_sql(self.name, check)
def create_sql(self, model, schema_editor):
check = self._get_check_sql(model, schema_editor)
return schema_editor._create_check_sql(model, self.name, check)
def remove_sql(self, model, schema_editor):
return schema_editor._delete_check_sql(model, self.name)
def validate(self, model, instance, exclude=None, using=DEFAULT_DB_ALIAS):
against = instance._get_field_value_map(meta=model._meta, exclude=exclude)
try:
if not Q(self.check).check(against, using=using):
raise ValidationError(self.get_violation_error_message())
except FieldError:
pass
def __repr__(self):
return "<%s: check=%s name=%s>" % (
self.__class__.__qualname__,
self.check,
repr(self.name),
)
def __eq__(self, other):
if isinstance(other, CheckConstraint):
return (
self.name == other.name
and self.check == other.check
and self.violation_error_message == other.violation_error_message
)
return super().__eq__(other)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
kwargs["check"] = self.check
return path, args, kwargs
class Deferrable(Enum):
DEFERRED = "deferred"
IMMEDIATE = "immediate"
# A similar format was proposed for Python 3.10.
def __repr__(self):
return f"{self.__class__.__qualname__}.{self._name_}"
class UniqueConstraint(BaseConstraint):
def __init__(
self,
*expressions,
fields=(),
name=None,
condition=None,
deferrable=None,
include=None,
opclasses=(),
violation_error_message=None,
):
if not name:
raise ValueError("A unique constraint must be named.")
if not expressions and not fields:
raise ValueError(
"At least one field or expression is required to define a "
"unique constraint."
)
if expressions and fields:
raise ValueError(
"UniqueConstraint.fields and expressions are mutually exclusive."
)
if not isinstance(condition, (type(None), Q)):
raise ValueError("UniqueConstraint.condition must be a Q instance.")
if condition and deferrable:
raise ValueError("UniqueConstraint with conditions cannot be deferred.")
if include and deferrable:
raise ValueError("UniqueConstraint with include fields cannot be deferred.")
if opclasses and deferrable:
raise ValueError("UniqueConstraint with opclasses cannot be deferred.")
if expressions and deferrable:
raise ValueError("UniqueConstraint with expressions cannot be deferred.")
if expressions and opclasses:
raise ValueError(
"UniqueConstraint.opclasses cannot be used with expressions. "
"Use django.contrib.postgres.indexes.OpClass() instead."
)
if not isinstance(deferrable, (type(None), Deferrable)):
raise ValueError(
"UniqueConstraint.deferrable must be a Deferrable instance."
)
if not isinstance(include, (type(None), list, tuple)):
raise ValueError("UniqueConstraint.include must be a list or tuple.")
if not isinstance(opclasses, (list, tuple)):
raise ValueError("UniqueConstraint.opclasses must be a list or tuple.")
if opclasses and len(fields) != len(opclasses):
raise ValueError(
"UniqueConstraint.fields and UniqueConstraint.opclasses must "
"have the same number of elements."
)
self.fields = tuple(fields)
self.condition = condition
self.deferrable = deferrable
self.include = tuple(include) if include else ()
self.opclasses = opclasses
self.expressions = tuple(
F(expression) if isinstance(expression, str) else expression
for expression in expressions
)
super().__init__(name, violation_error_message=violation_error_message)
@property
def contains_expressions(self):
return bool(self.expressions)
def _get_condition_sql(self, model, schema_editor):
if self.condition is None:
return None
query = Query(model=model, alias_cols=False)
where = query.build_where(self.condition)
compiler = query.get_compiler(connection=schema_editor.connection)
sql, params = where.as_sql(compiler, schema_editor.connection)
return sql % tuple(schema_editor.quote_value(p) for p in params)
def _get_index_expressions(self, model, schema_editor):
if not self.expressions:
return None
index_expressions = []
for expression in self.expressions:
index_expression = IndexExpression(expression)
index_expression.set_wrapper_classes(schema_editor.connection)
index_expressions.append(index_expression)
return ExpressionList(*index_expressions).resolve_expression(
Query(model, alias_cols=False),
)
def constraint_sql(self, model, schema_editor):
fields = [model._meta.get_field(field_name) for field_name in self.fields]
include = [
model._meta.get_field(field_name).column for field_name in self.include
]
condition = self._get_condition_sql(model, schema_editor)
expressions = self._get_index_expressions(model, schema_editor)
return schema_editor._unique_sql(
model,
fields,
self.name,
condition=condition,
deferrable=self.deferrable,
include=include,
opclasses=self.opclasses,
expressions=expressions,
)
def create_sql(self, model, schema_editor):
fields = [model._meta.get_field(field_name) for field_name in self.fields]
include = [
model._meta.get_field(field_name).column for field_name in self.include
]
condition = self._get_condition_sql(model, schema_editor)
expressions = self._get_index_expressions(model, schema_editor)
return schema_editor._create_unique_sql(
model,
fields,
self.name,
condition=condition,
deferrable=self.deferrable,
include=include,
opclasses=self.opclasses,
expressions=expressions,
)
def remove_sql(self, model, schema_editor):
condition = self._get_condition_sql(model, schema_editor)
include = [
model._meta.get_field(field_name).column for field_name in self.include
]
expressions = self._get_index_expressions(model, schema_editor)
return schema_editor._delete_unique_sql(
model,
self.name,
condition=condition,
deferrable=self.deferrable,
include=include,
opclasses=self.opclasses,
expressions=expressions,
)
def __repr__(self):
return "<%s:%s%s%s%s%s%s%s>" % (
self.__class__.__qualname__,
"" if not self.fields else " fields=%s" % repr(self.fields),
"" if not self.expressions else " expressions=%s" % repr(self.expressions),
" name=%s" % repr(self.name),
"" if self.condition is None else " condition=%s" % self.condition,
"" if self.deferrable is None else " deferrable=%r" % self.deferrable,
"" if not self.include else " include=%s" % repr(self.include),
"" if not self.opclasses else " opclasses=%s" % repr(self.opclasses),
)
def __eq__(self, other):
if isinstance(other, UniqueConstraint):
return (
self.name == other.name
and self.fields == other.fields
and self.condition == other.condition
and self.deferrable == other.deferrable
and self.include == other.include
and self.opclasses == other.opclasses
and self.expressions == other.expressions
and self.violation_error_message == other.violation_error_message
)
return super().__eq__(other)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fields:
kwargs["fields"] = self.fields
if self.condition:
kwargs["condition"] = self.condition
if self.deferrable:
kwargs["deferrable"] = self.deferrable
if self.include:
kwargs["include"] = self.include
if self.opclasses:
kwargs["opclasses"] = self.opclasses
return path, self.expressions, kwargs
def validate(self, model, instance, exclude=None, using=DEFAULT_DB_ALIAS):
queryset = model._default_manager.using(using)
if self.fields:
lookup_kwargs = {}
for field_name in self.fields:
if exclude and field_name in exclude:
return
field = model._meta.get_field(field_name)
lookup_value = getattr(instance, field.attname)
if lookup_value is None or (
lookup_value == ""
and connections[using].features.interprets_empty_strings_as_nulls
):
# A composite constraint containing NULL value cannot cause
# a violation since NULL != NULL in SQL.
return
lookup_kwargs[field.name] = lookup_value
queryset = queryset.filter(**lookup_kwargs)
else:
# Ignore constraints with excluded fields.
if exclude:
for expression in self.expressions:
if hasattr(expression, "flatten"):
for expr in expression.flatten():
if isinstance(expr, F) and expr.name in exclude:
return
elif isinstance(expression, F) and expression.name in exclude:
return
replacements = {
F(field): value
for field, value in instance._get_field_value_map(
meta=model._meta, exclude=exclude
).items()
}
expressions = []
for expr in self.expressions:
# Ignore ordering.
if isinstance(expr, OrderBy):
expr = expr.expression
expressions.append(Exact(expr, expr.replace_expressions(replacements)))
queryset = queryset.filter(*expressions)
model_class_pk = instance._get_pk_val(model._meta)
if not instance._state.adding and model_class_pk is not None:
queryset = queryset.exclude(pk=model_class_pk)
if not self.condition:
if queryset.exists():
if self.expressions:
raise ValidationError(self.get_violation_error_message())
# When fields are defined, use the unique_error_message() for
# backward compatibility.
for model, constraints in instance.get_constraints():
for constraint in constraints:
if constraint is self:
raise ValidationError(
instance.unique_error_message(model, self.fields)
)
else:
against = instance._get_field_value_map(meta=model._meta, exclude=exclude)
try:
if (self.condition & Exists(queryset.filter(self.condition))).check(
against, using=using
):
raise ValidationError(self.get_violation_error_message())
except FieldError:
pass
|
castiel248/Convert
|
Lib/site-packages/django/db/models/constraints.py
|
Python
|
mit
| 15,389 |
from collections import Counter, defaultdict
from functools import partial, reduce
from itertools import chain
from operator import attrgetter, or_
from django.db import IntegrityError, connections, models, transaction
from django.db.models import query_utils, signals, sql
class ProtectedError(IntegrityError):
def __init__(self, msg, protected_objects):
self.protected_objects = protected_objects
super().__init__(msg, protected_objects)
class RestrictedError(IntegrityError):
def __init__(self, msg, restricted_objects):
self.restricted_objects = restricted_objects
super().__init__(msg, restricted_objects)
def CASCADE(collector, field, sub_objs, using):
collector.collect(
sub_objs,
source=field.remote_field.model,
source_attr=field.name,
nullable=field.null,
fail_on_restricted=False,
)
if field.null and not connections[using].features.can_defer_constraint_checks:
collector.add_field_update(field, None, sub_objs)
def PROTECT(collector, field, sub_objs, using):
raise ProtectedError(
"Cannot delete some instances of model '%s' because they are "
"referenced through a protected foreign key: '%s.%s'"
% (
field.remote_field.model.__name__,
sub_objs[0].__class__.__name__,
field.name,
),
sub_objs,
)
def RESTRICT(collector, field, sub_objs, using):
collector.add_restricted_objects(field, sub_objs)
collector.add_dependency(field.remote_field.model, field.model)
def SET(value):
if callable(value):
def set_on_delete(collector, field, sub_objs, using):
collector.add_field_update(field, value(), sub_objs)
else:
def set_on_delete(collector, field, sub_objs, using):
collector.add_field_update(field, value, sub_objs)
set_on_delete.deconstruct = lambda: ("django.db.models.SET", (value,), {})
set_on_delete.lazy_sub_objs = True
return set_on_delete
def SET_NULL(collector, field, sub_objs, using):
collector.add_field_update(field, None, sub_objs)
SET_NULL.lazy_sub_objs = True
def SET_DEFAULT(collector, field, sub_objs, using):
collector.add_field_update(field, field.get_default(), sub_objs)
SET_DEFAULT.lazy_sub_objs = True
def DO_NOTHING(collector, field, sub_objs, using):
pass
def get_candidate_relations_to_delete(opts):
# The candidate relations are the ones that come from N-1 and 1-1 relations.
# N-N (i.e., many-to-many) relations aren't candidates for deletion.
return (
f
for f in opts.get_fields(include_hidden=True)
if f.auto_created and not f.concrete and (f.one_to_one or f.one_to_many)
)
class Collector:
def __init__(self, using, origin=None):
self.using = using
# A Model or QuerySet object.
self.origin = origin
# Initially, {model: {instances}}, later values become lists.
self.data = defaultdict(set)
# {(field, value): [instances, …]}
self.field_updates = defaultdict(list)
# {model: {field: {instances}}}
self.restricted_objects = defaultdict(partial(defaultdict, set))
# fast_deletes is a list of queryset-likes that can be deleted without
# fetching the objects into memory.
self.fast_deletes = []
# Tracks deletion-order dependency for databases without transactions
# or ability to defer constraint checks. Only concrete model classes
# should be included, as the dependencies exist only between actual
# database tables; proxy models are represented here by their concrete
# parent.
self.dependencies = defaultdict(set) # {model: {models}}
def add(self, objs, source=None, nullable=False, reverse_dependency=False):
"""
Add 'objs' to the collection of objects to be deleted. If the call is
the result of a cascade, 'source' should be the model that caused it,
and 'nullable' should be set to True if the relation can be null.
Return a list of all objects that were not already collected.
"""
if not objs:
return []
new_objs = []
model = objs[0].__class__
instances = self.data[model]
for obj in objs:
if obj not in instances:
new_objs.append(obj)
instances.update(new_objs)
# Nullable relationships can be ignored -- they are nulled out before
# deleting, and therefore do not affect the order in which objects have
# to be deleted.
if source is not None and not nullable:
self.add_dependency(source, model, reverse_dependency=reverse_dependency)
return new_objs
def add_dependency(self, model, dependency, reverse_dependency=False):
if reverse_dependency:
model, dependency = dependency, model
self.dependencies[model._meta.concrete_model].add(
dependency._meta.concrete_model
)
self.data.setdefault(dependency, self.data.default_factory())
def add_field_update(self, field, value, objs):
"""
Schedule a field update. 'objs' must be a homogeneous iterable
collection of model instances (e.g. a QuerySet).
"""
self.field_updates[field, value].append(objs)
def add_restricted_objects(self, field, objs):
if objs:
model = objs[0].__class__
self.restricted_objects[model][field].update(objs)
def clear_restricted_objects_from_set(self, model, objs):
if model in self.restricted_objects:
self.restricted_objects[model] = {
field: items - objs
for field, items in self.restricted_objects[model].items()
}
def clear_restricted_objects_from_queryset(self, model, qs):
if model in self.restricted_objects:
objs = set(
qs.filter(
pk__in=[
obj.pk
for objs in self.restricted_objects[model].values()
for obj in objs
]
)
)
self.clear_restricted_objects_from_set(model, objs)
def _has_signal_listeners(self, model):
return signals.pre_delete.has_listeners(
model
) or signals.post_delete.has_listeners(model)
def can_fast_delete(self, objs, from_field=None):
"""
Determine if the objects in the given queryset-like or single object
can be fast-deleted. This can be done if there are no cascades, no
parents and no signal listeners for the object class.
The 'from_field' tells where we are coming from - we need this to
determine if the objects are in fact to be deleted. Allow also
skipping parent -> child -> parent chain preventing fast delete of
the child.
"""
if from_field and from_field.remote_field.on_delete is not CASCADE:
return False
if hasattr(objs, "_meta"):
model = objs._meta.model
elif hasattr(objs, "model") and hasattr(objs, "_raw_delete"):
model = objs.model
else:
return False
if self._has_signal_listeners(model):
return False
# The use of from_field comes from the need to avoid cascade back to
# parent when parent delete is cascading to child.
opts = model._meta
return (
all(
link == from_field
for link in opts.concrete_model._meta.parents.values()
)
and
# Foreign keys pointing to this model.
all(
related.field.remote_field.on_delete is DO_NOTHING
for related in get_candidate_relations_to_delete(opts)
)
and (
# Something like generic foreign key.
not any(
hasattr(field, "bulk_related_objects")
for field in opts.private_fields
)
)
)
def get_del_batches(self, objs, fields):
"""
Return the objs in suitably sized batches for the used connection.
"""
field_names = [field.name for field in fields]
conn_batch_size = max(
connections[self.using].ops.bulk_batch_size(field_names, objs), 1
)
if len(objs) > conn_batch_size:
return [
objs[i : i + conn_batch_size]
for i in range(0, len(objs), conn_batch_size)
]
else:
return [objs]
def collect(
self,
objs,
source=None,
nullable=False,
collect_related=True,
source_attr=None,
reverse_dependency=False,
keep_parents=False,
fail_on_restricted=True,
):
"""
Add 'objs' to the collection of objects to be deleted as well as all
parent instances. 'objs' must be a homogeneous iterable collection of
model instances (e.g. a QuerySet). If 'collect_related' is True,
related objects will be handled by their respective on_delete handler.
If the call is the result of a cascade, 'source' should be the model
that caused it and 'nullable' should be set to True, if the relation
can be null.
If 'reverse_dependency' is True, 'source' will be deleted before the
current model, rather than after. (Needed for cascading to parent
models, the one case in which the cascade follows the forwards
direction of an FK rather than the reverse direction.)
If 'keep_parents' is True, data of parent model's will be not deleted.
If 'fail_on_restricted' is False, error won't be raised even if it's
prohibited to delete such objects due to RESTRICT, that defers
restricted object checking in recursive calls where the top-level call
may need to collect more objects to determine whether restricted ones
can be deleted.
"""
if self.can_fast_delete(objs):
self.fast_deletes.append(objs)
return
new_objs = self.add(
objs, source, nullable, reverse_dependency=reverse_dependency
)
if not new_objs:
return
model = new_objs[0].__class__
if not keep_parents:
# Recursively collect concrete model's parent models, but not their
# related objects. These will be found by meta.get_fields()
concrete_model = model._meta.concrete_model
for ptr in concrete_model._meta.parents.values():
if ptr:
parent_objs = [getattr(obj, ptr.name) for obj in new_objs]
self.collect(
parent_objs,
source=model,
source_attr=ptr.remote_field.related_name,
collect_related=False,
reverse_dependency=True,
fail_on_restricted=False,
)
if not collect_related:
return
if keep_parents:
parents = set(model._meta.get_parent_list())
model_fast_deletes = defaultdict(list)
protected_objects = defaultdict(list)
for related in get_candidate_relations_to_delete(model._meta):
# Preserve parent reverse relationships if keep_parents=True.
if keep_parents and related.model in parents:
continue
field = related.field
on_delete = field.remote_field.on_delete
if on_delete == DO_NOTHING:
continue
related_model = related.related_model
if self.can_fast_delete(related_model, from_field=field):
model_fast_deletes[related_model].append(field)
continue
batches = self.get_del_batches(new_objs, [field])
for batch in batches:
sub_objs = self.related_objects(related_model, [field], batch)
# Non-referenced fields can be deferred if no signal receivers
# are connected for the related model as they'll never be
# exposed to the user. Skip field deferring when some
# relationships are select_related as interactions between both
# features are hard to get right. This should only happen in
# the rare cases where .related_objects is overridden anyway.
if not (
sub_objs.query.select_related
or self._has_signal_listeners(related_model)
):
referenced_fields = set(
chain.from_iterable(
(rf.attname for rf in rel.field.foreign_related_fields)
for rel in get_candidate_relations_to_delete(
related_model._meta
)
)
)
sub_objs = sub_objs.only(*tuple(referenced_fields))
if getattr(on_delete, "lazy_sub_objs", False) or sub_objs:
try:
on_delete(self, field, sub_objs, self.using)
except ProtectedError as error:
key = "'%s.%s'" % (field.model.__name__, field.name)
protected_objects[key] += error.protected_objects
if protected_objects:
raise ProtectedError(
"Cannot delete some instances of model %r because they are "
"referenced through protected foreign keys: %s."
% (
model.__name__,
", ".join(protected_objects),
),
set(chain.from_iterable(protected_objects.values())),
)
for related_model, related_fields in model_fast_deletes.items():
batches = self.get_del_batches(new_objs, related_fields)
for batch in batches:
sub_objs = self.related_objects(related_model, related_fields, batch)
self.fast_deletes.append(sub_objs)
for field in model._meta.private_fields:
if hasattr(field, "bulk_related_objects"):
# It's something like generic foreign key.
sub_objs = field.bulk_related_objects(new_objs, self.using)
self.collect(
sub_objs, source=model, nullable=True, fail_on_restricted=False
)
if fail_on_restricted:
# Raise an error if collected restricted objects (RESTRICT) aren't
# candidates for deletion also collected via CASCADE.
for related_model, instances in self.data.items():
self.clear_restricted_objects_from_set(related_model, instances)
for qs in self.fast_deletes:
self.clear_restricted_objects_from_queryset(qs.model, qs)
if self.restricted_objects.values():
restricted_objects = defaultdict(list)
for related_model, fields in self.restricted_objects.items():
for field, objs in fields.items():
if objs:
key = "'%s.%s'" % (related_model.__name__, field.name)
restricted_objects[key] += objs
if restricted_objects:
raise RestrictedError(
"Cannot delete some instances of model %r because "
"they are referenced through restricted foreign keys: "
"%s."
% (
model.__name__,
", ".join(restricted_objects),
),
set(chain.from_iterable(restricted_objects.values())),
)
def related_objects(self, related_model, related_fields, objs):
"""
Get a QuerySet of the related model to objs via related fields.
"""
predicate = query_utils.Q.create(
[(f"{related_field.name}__in", objs) for related_field in related_fields],
connector=query_utils.Q.OR,
)
return related_model._base_manager.using(self.using).filter(predicate)
def instances_with_model(self):
for model, instances in self.data.items():
for obj in instances:
yield model, obj
def sort(self):
sorted_models = []
concrete_models = set()
models = list(self.data)
while len(sorted_models) < len(models):
found = False
for model in models:
if model in sorted_models:
continue
dependencies = self.dependencies.get(model._meta.concrete_model)
if not (dependencies and dependencies.difference(concrete_models)):
sorted_models.append(model)
concrete_models.add(model._meta.concrete_model)
found = True
if not found:
return
self.data = {model: self.data[model] for model in sorted_models}
def delete(self):
# sort instance collections
for model, instances in self.data.items():
self.data[model] = sorted(instances, key=attrgetter("pk"))
# if possible, bring the models in an order suitable for databases that
# don't support transactions or cannot defer constraint checks until the
# end of a transaction.
self.sort()
# number of objects deleted for each model label
deleted_counter = Counter()
# Optimize for the case with a single obj and no dependencies
if len(self.data) == 1 and len(instances) == 1:
instance = list(instances)[0]
if self.can_fast_delete(instance):
with transaction.mark_for_rollback_on_error(self.using):
count = sql.DeleteQuery(model).delete_batch(
[instance.pk], self.using
)
setattr(instance, model._meta.pk.attname, None)
return count, {model._meta.label: count}
with transaction.atomic(using=self.using, savepoint=False):
# send pre_delete signals
for model, obj in self.instances_with_model():
if not model._meta.auto_created:
signals.pre_delete.send(
sender=model,
instance=obj,
using=self.using,
origin=self.origin,
)
# fast deletes
for qs in self.fast_deletes:
count = qs._raw_delete(using=self.using)
if count:
deleted_counter[qs.model._meta.label] += count
# update fields
for (field, value), instances_list in self.field_updates.items():
updates = []
objs = []
for instances in instances_list:
if (
isinstance(instances, models.QuerySet)
and instances._result_cache is None
):
updates.append(instances)
else:
objs.extend(instances)
if updates:
combined_updates = reduce(or_, updates)
combined_updates.update(**{field.name: value})
if objs:
model = objs[0].__class__
query = sql.UpdateQuery(model)
query.update_batch(
list({obj.pk for obj in objs}), {field.name: value}, self.using
)
# reverse instance collections
for instances in self.data.values():
instances.reverse()
# delete instances
for model, instances in self.data.items():
query = sql.DeleteQuery(model)
pk_list = [obj.pk for obj in instances]
count = query.delete_batch(pk_list, self.using)
if count:
deleted_counter[model._meta.label] += count
if not model._meta.auto_created:
for obj in instances:
signals.post_delete.send(
sender=model,
instance=obj,
using=self.using,
origin=self.origin,
)
for model, instances in self.data.items():
for instance in instances:
setattr(instance, model._meta.pk.attname, None)
return sum(deleted_counter.values()), dict(deleted_counter)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/deletion.py
|
Python
|
mit
| 21,099 |
import enum
from types import DynamicClassAttribute
from django.utils.functional import Promise
__all__ = ["Choices", "IntegerChoices", "TextChoices"]
class ChoicesMeta(enum.EnumMeta):
"""A metaclass for creating a enum choices."""
def __new__(metacls, classname, bases, classdict, **kwds):
labels = []
for key in classdict._member_names:
value = classdict[key]
if (
isinstance(value, (list, tuple))
and len(value) > 1
and isinstance(value[-1], (Promise, str))
):
*value, label = value
value = tuple(value)
else:
label = key.replace("_", " ").title()
labels.append(label)
# Use dict.__setitem__() to suppress defenses against double
# assignment in enum's classdict.
dict.__setitem__(classdict, key, value)
cls = super().__new__(metacls, classname, bases, classdict, **kwds)
for member, label in zip(cls.__members__.values(), labels):
member._label_ = label
return enum.unique(cls)
def __contains__(cls, member):
if not isinstance(member, enum.Enum):
# Allow non-enums to match against member values.
return any(x.value == member for x in cls)
return super().__contains__(member)
@property
def names(cls):
empty = ["__empty__"] if hasattr(cls, "__empty__") else []
return empty + [member.name for member in cls]
@property
def choices(cls):
empty = [(None, cls.__empty__)] if hasattr(cls, "__empty__") else []
return empty + [(member.value, member.label) for member in cls]
@property
def labels(cls):
return [label for _, label in cls.choices]
@property
def values(cls):
return [value for value, _ in cls.choices]
class Choices(enum.Enum, metaclass=ChoicesMeta):
"""Class for creating enumerated choices."""
@DynamicClassAttribute
def label(self):
return self._label_
@property
def do_not_call_in_templates(self):
return True
def __str__(self):
"""
Use value when cast to str, so that Choices set as model instance
attributes are rendered as expected in templates and similar contexts.
"""
return str(self.value)
# A similar format was proposed for Python 3.10.
def __repr__(self):
return f"{self.__class__.__qualname__}.{self._name_}"
class IntegerChoices(int, Choices):
"""Class for creating enumerated integer choices."""
pass
class TextChoices(str, Choices):
"""Class for creating enumerated string choices."""
def _generate_next_value_(name, start, count, last_values):
return name
|
castiel248/Convert
|
Lib/site-packages/django/db/models/enums.py
|
Python
|
mit
| 2,804 |
import copy
import datetime
import functools
import inspect
import warnings
from collections import defaultdict
from decimal import Decimal
from uuid import UUID
from django.core.exceptions import EmptyResultSet, FieldError, FullResultSet
from django.db import DatabaseError, NotSupportedError, connection
from django.db.models import fields
from django.db.models.constants import LOOKUP_SEP
from django.db.models.query_utils import Q
from django.utils.deconstruct import deconstructible
from django.utils.deprecation import RemovedInDjango50Warning
from django.utils.functional import cached_property
from django.utils.hashable import make_hashable
class SQLiteNumericMixin:
"""
Some expressions with output_field=DecimalField() must be cast to
numeric to be properly filtered.
"""
def as_sqlite(self, compiler, connection, **extra_context):
sql, params = self.as_sql(compiler, connection, **extra_context)
try:
if self.output_field.get_internal_type() == "DecimalField":
sql = "CAST(%s AS NUMERIC)" % sql
except FieldError:
pass
return sql, params
class Combinable:
"""
Provide the ability to combine one or two objects with
some connector. For example F('foo') + F('bar').
"""
# Arithmetic connectors
ADD = "+"
SUB = "-"
MUL = "*"
DIV = "/"
POW = "^"
# The following is a quoted % operator - it is quoted because it can be
# used in strings that also have parameter substitution.
MOD = "%%"
# Bitwise operators - note that these are generated by .bitand()
# and .bitor(), the '&' and '|' are reserved for boolean operator
# usage.
BITAND = "&"
BITOR = "|"
BITLEFTSHIFT = "<<"
BITRIGHTSHIFT = ">>"
BITXOR = "#"
def _combine(self, other, connector, reversed):
if not hasattr(other, "resolve_expression"):
# everything must be resolvable to an expression
other = Value(other)
if reversed:
return CombinedExpression(other, connector, self)
return CombinedExpression(self, connector, other)
#############
# OPERATORS #
#############
def __neg__(self):
return self._combine(-1, self.MUL, False)
def __add__(self, other):
return self._combine(other, self.ADD, False)
def __sub__(self, other):
return self._combine(other, self.SUB, False)
def __mul__(self, other):
return self._combine(other, self.MUL, False)
def __truediv__(self, other):
return self._combine(other, self.DIV, False)
def __mod__(self, other):
return self._combine(other, self.MOD, False)
def __pow__(self, other):
return self._combine(other, self.POW, False)
def __and__(self, other):
if getattr(self, "conditional", False) and getattr(other, "conditional", False):
return Q(self) & Q(other)
raise NotImplementedError(
"Use .bitand(), .bitor(), and .bitxor() for bitwise logical operations."
)
def bitand(self, other):
return self._combine(other, self.BITAND, False)
def bitleftshift(self, other):
return self._combine(other, self.BITLEFTSHIFT, False)
def bitrightshift(self, other):
return self._combine(other, self.BITRIGHTSHIFT, False)
def __xor__(self, other):
if getattr(self, "conditional", False) and getattr(other, "conditional", False):
return Q(self) ^ Q(other)
raise NotImplementedError(
"Use .bitand(), .bitor(), and .bitxor() for bitwise logical operations."
)
def bitxor(self, other):
return self._combine(other, self.BITXOR, False)
def __or__(self, other):
if getattr(self, "conditional", False) and getattr(other, "conditional", False):
return Q(self) | Q(other)
raise NotImplementedError(
"Use .bitand(), .bitor(), and .bitxor() for bitwise logical operations."
)
def bitor(self, other):
return self._combine(other, self.BITOR, False)
def __radd__(self, other):
return self._combine(other, self.ADD, True)
def __rsub__(self, other):
return self._combine(other, self.SUB, True)
def __rmul__(self, other):
return self._combine(other, self.MUL, True)
def __rtruediv__(self, other):
return self._combine(other, self.DIV, True)
def __rmod__(self, other):
return self._combine(other, self.MOD, True)
def __rpow__(self, other):
return self._combine(other, self.POW, True)
def __rand__(self, other):
raise NotImplementedError(
"Use .bitand(), .bitor(), and .bitxor() for bitwise logical operations."
)
def __ror__(self, other):
raise NotImplementedError(
"Use .bitand(), .bitor(), and .bitxor() for bitwise logical operations."
)
def __rxor__(self, other):
raise NotImplementedError(
"Use .bitand(), .bitor(), and .bitxor() for bitwise logical operations."
)
def __invert__(self):
return NegatedExpression(self)
class BaseExpression:
"""Base class for all query expressions."""
empty_result_set_value = NotImplemented
# aggregate specific fields
is_summary = False
_output_field_resolved_to_none = False
# Can the expression be used in a WHERE clause?
filterable = True
# Can the expression can be used as a source expression in Window?
window_compatible = False
def __init__(self, output_field=None):
if output_field is not None:
self.output_field = output_field
def __getstate__(self):
state = self.__dict__.copy()
state.pop("convert_value", None)
return state
def get_db_converters(self, connection):
return (
[]
if self.convert_value is self._convert_value_noop
else [self.convert_value]
) + self.output_field.get_db_converters(connection)
def get_source_expressions(self):
return []
def set_source_expressions(self, exprs):
assert not exprs
def _parse_expressions(self, *expressions):
return [
arg
if hasattr(arg, "resolve_expression")
else (F(arg) if isinstance(arg, str) else Value(arg))
for arg in expressions
]
def as_sql(self, compiler, connection):
"""
Responsible for returning a (sql, [params]) tuple to be included
in the current query.
Different backends can provide their own implementation, by
providing an `as_{vendor}` method and patching the Expression:
```
def override_as_sql(self, compiler, connection):
# custom logic
return super().as_sql(compiler, connection)
setattr(Expression, 'as_' + connection.vendor, override_as_sql)
```
Arguments:
* compiler: the query compiler responsible for generating the query.
Must have a compile method, returning a (sql, [params]) tuple.
Calling compiler(value) will return a quoted `value`.
* connection: the database connection used for the current query.
Return: (sql, params)
Where `sql` is a string containing ordered sql parameters to be
replaced with the elements of the list `params`.
"""
raise NotImplementedError("Subclasses must implement as_sql()")
@cached_property
def contains_aggregate(self):
return any(
expr and expr.contains_aggregate for expr in self.get_source_expressions()
)
@cached_property
def contains_over_clause(self):
return any(
expr and expr.contains_over_clause for expr in self.get_source_expressions()
)
@cached_property
def contains_column_references(self):
return any(
expr and expr.contains_column_references
for expr in self.get_source_expressions()
)
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
"""
Provide the chance to do any preprocessing or validation before being
added to the query.
Arguments:
* query: the backend query implementation
* allow_joins: boolean allowing or denying use of joins
in this query
* reuse: a set of reusable joins for multijoins
* summarize: a terminal aggregate clause
* for_save: whether this expression about to be used in a save or update
Return: an Expression to be added to the query.
"""
c = self.copy()
c.is_summary = summarize
c.set_source_expressions(
[
expr.resolve_expression(query, allow_joins, reuse, summarize)
if expr
else None
for expr in c.get_source_expressions()
]
)
return c
@property
def conditional(self):
return isinstance(self.output_field, fields.BooleanField)
@property
def field(self):
return self.output_field
@cached_property
def output_field(self):
"""Return the output type of this expressions."""
output_field = self._resolve_output_field()
if output_field is None:
self._output_field_resolved_to_none = True
raise FieldError("Cannot resolve expression type, unknown output_field")
return output_field
@cached_property
def _output_field_or_none(self):
"""
Return the output field of this expression, or None if
_resolve_output_field() didn't return an output type.
"""
try:
return self.output_field
except FieldError:
if not self._output_field_resolved_to_none:
raise
def _resolve_output_field(self):
"""
Attempt to infer the output type of the expression.
As a guess, if the output fields of all source fields match then simply
infer the same type here.
If a source's output field resolves to None, exclude it from this check.
If all sources are None, then an error is raised higher up the stack in
the output_field property.
"""
# This guess is mostly a bad idea, but there is quite a lot of code
# (especially 3rd party Func subclasses) that depend on it, we'd need a
# deprecation path to fix it.
sources_iter = (
source for source in self.get_source_fields() if source is not None
)
for output_field in sources_iter:
for source in sources_iter:
if not isinstance(output_field, source.__class__):
raise FieldError(
"Expression contains mixed types: %s, %s. You must "
"set output_field."
% (
output_field.__class__.__name__,
source.__class__.__name__,
)
)
return output_field
@staticmethod
def _convert_value_noop(value, expression, connection):
return value
@cached_property
def convert_value(self):
"""
Expressions provide their own converters because users have the option
of manually specifying the output_field which may be a different type
from the one the database returns.
"""
field = self.output_field
internal_type = field.get_internal_type()
if internal_type == "FloatField":
return (
lambda value, expression, connection: None
if value is None
else float(value)
)
elif internal_type.endswith("IntegerField"):
return (
lambda value, expression, connection: None
if value is None
else int(value)
)
elif internal_type == "DecimalField":
return (
lambda value, expression, connection: None
if value is None
else Decimal(value)
)
return self._convert_value_noop
def get_lookup(self, lookup):
return self.output_field.get_lookup(lookup)
def get_transform(self, name):
return self.output_field.get_transform(name)
def relabeled_clone(self, change_map):
clone = self.copy()
clone.set_source_expressions(
[
e.relabeled_clone(change_map) if e is not None else None
for e in self.get_source_expressions()
]
)
return clone
def replace_expressions(self, replacements):
if replacement := replacements.get(self):
return replacement
clone = self.copy()
source_expressions = clone.get_source_expressions()
clone.set_source_expressions(
[
expr.replace_expressions(replacements) if expr else None
for expr in source_expressions
]
)
return clone
def get_refs(self):
refs = set()
for expr in self.get_source_expressions():
refs |= expr.get_refs()
return refs
def copy(self):
return copy.copy(self)
def prefix_references(self, prefix):
clone = self.copy()
clone.set_source_expressions(
[
F(f"{prefix}{expr.name}")
if isinstance(expr, F)
else expr.prefix_references(prefix)
for expr in self.get_source_expressions()
]
)
return clone
def get_group_by_cols(self):
if not self.contains_aggregate:
return [self]
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
def get_source_fields(self):
"""Return the underlying field types used by this aggregate."""
return [e._output_field_or_none for e in self.get_source_expressions()]
def asc(self, **kwargs):
return OrderBy(self, **kwargs)
def desc(self, **kwargs):
return OrderBy(self, descending=True, **kwargs)
def reverse_ordering(self):
return self
def flatten(self):
"""
Recursively yield this expression and all subexpressions, in
depth-first order.
"""
yield self
for expr in self.get_source_expressions():
if expr:
if hasattr(expr, "flatten"):
yield from expr.flatten()
else:
yield expr
def select_format(self, compiler, sql, params):
"""
Custom format for select clauses. For example, EXISTS expressions need
to be wrapped in CASE WHEN on Oracle.
"""
if hasattr(self.output_field, "select_format"):
return self.output_field.select_format(compiler, sql, params)
return sql, params
@deconstructible
class Expression(BaseExpression, Combinable):
"""An expression that can be combined with other expressions."""
@cached_property
def identity(self):
constructor_signature = inspect.signature(self.__init__)
args, kwargs = self._constructor_args
signature = constructor_signature.bind_partial(*args, **kwargs)
signature.apply_defaults()
arguments = signature.arguments.items()
identity = [self.__class__]
for arg, value in arguments:
if isinstance(value, fields.Field):
if value.name and value.model:
value = (value.model._meta.label, value.name)
else:
value = type(value)
else:
value = make_hashable(value)
identity.append((arg, value))
return tuple(identity)
def __eq__(self, other):
if not isinstance(other, Expression):
return NotImplemented
return other.identity == self.identity
def __hash__(self):
return hash(self.identity)
# Type inference for CombinedExpression.output_field.
# Missing items will result in FieldError, by design.
#
# The current approach for NULL is based on lowest common denominator behavior
# i.e. if one of the supported databases is raising an error (rather than
# return NULL) for `val <op> NULL`, then Django raises FieldError.
NoneType = type(None)
_connector_combinations = [
# Numeric operations - operands of same type.
{
connector: [
(fields.IntegerField, fields.IntegerField, fields.IntegerField),
(fields.FloatField, fields.FloatField, fields.FloatField),
(fields.DecimalField, fields.DecimalField, fields.DecimalField),
]
for connector in (
Combinable.ADD,
Combinable.SUB,
Combinable.MUL,
# Behavior for DIV with integer arguments follows Postgres/SQLite,
# not MySQL/Oracle.
Combinable.DIV,
Combinable.MOD,
Combinable.POW,
)
},
# Numeric operations - operands of different type.
{
connector: [
(fields.IntegerField, fields.DecimalField, fields.DecimalField),
(fields.DecimalField, fields.IntegerField, fields.DecimalField),
(fields.IntegerField, fields.FloatField, fields.FloatField),
(fields.FloatField, fields.IntegerField, fields.FloatField),
]
for connector in (
Combinable.ADD,
Combinable.SUB,
Combinable.MUL,
Combinable.DIV,
Combinable.MOD,
)
},
# Bitwise operators.
{
connector: [
(fields.IntegerField, fields.IntegerField, fields.IntegerField),
]
for connector in (
Combinable.BITAND,
Combinable.BITOR,
Combinable.BITLEFTSHIFT,
Combinable.BITRIGHTSHIFT,
Combinable.BITXOR,
)
},
# Numeric with NULL.
{
connector: [
(field_type, NoneType, field_type),
(NoneType, field_type, field_type),
]
for connector in (
Combinable.ADD,
Combinable.SUB,
Combinable.MUL,
Combinable.DIV,
Combinable.MOD,
Combinable.POW,
)
for field_type in (fields.IntegerField, fields.DecimalField, fields.FloatField)
},
# Date/DateTimeField/DurationField/TimeField.
{
Combinable.ADD: [
# Date/DateTimeField.
(fields.DateField, fields.DurationField, fields.DateTimeField),
(fields.DateTimeField, fields.DurationField, fields.DateTimeField),
(fields.DurationField, fields.DateField, fields.DateTimeField),
(fields.DurationField, fields.DateTimeField, fields.DateTimeField),
# DurationField.
(fields.DurationField, fields.DurationField, fields.DurationField),
# TimeField.
(fields.TimeField, fields.DurationField, fields.TimeField),
(fields.DurationField, fields.TimeField, fields.TimeField),
],
},
{
Combinable.SUB: [
# Date/DateTimeField.
(fields.DateField, fields.DurationField, fields.DateTimeField),
(fields.DateTimeField, fields.DurationField, fields.DateTimeField),
(fields.DateField, fields.DateField, fields.DurationField),
(fields.DateField, fields.DateTimeField, fields.DurationField),
(fields.DateTimeField, fields.DateField, fields.DurationField),
(fields.DateTimeField, fields.DateTimeField, fields.DurationField),
# DurationField.
(fields.DurationField, fields.DurationField, fields.DurationField),
# TimeField.
(fields.TimeField, fields.DurationField, fields.TimeField),
(fields.TimeField, fields.TimeField, fields.DurationField),
],
},
]
_connector_combinators = defaultdict(list)
def register_combinable_fields(lhs, connector, rhs, result):
"""
Register combinable types:
lhs <connector> rhs -> result
e.g.
register_combinable_fields(
IntegerField, Combinable.ADD, FloatField, FloatField
)
"""
_connector_combinators[connector].append((lhs, rhs, result))
for d in _connector_combinations:
for connector, field_types in d.items():
for lhs, rhs, result in field_types:
register_combinable_fields(lhs, connector, rhs, result)
@functools.lru_cache(maxsize=128)
def _resolve_combined_type(connector, lhs_type, rhs_type):
combinators = _connector_combinators.get(connector, ())
for combinator_lhs_type, combinator_rhs_type, combined_type in combinators:
if issubclass(lhs_type, combinator_lhs_type) and issubclass(
rhs_type, combinator_rhs_type
):
return combined_type
class CombinedExpression(SQLiteNumericMixin, Expression):
def __init__(self, lhs, connector, rhs, output_field=None):
super().__init__(output_field=output_field)
self.connector = connector
self.lhs = lhs
self.rhs = rhs
def __repr__(self):
return "<{}: {}>".format(self.__class__.__name__, self)
def __str__(self):
return "{} {} {}".format(self.lhs, self.connector, self.rhs)
def get_source_expressions(self):
return [self.lhs, self.rhs]
def set_source_expressions(self, exprs):
self.lhs, self.rhs = exprs
def _resolve_output_field(self):
# We avoid using super() here for reasons given in
# Expression._resolve_output_field()
combined_type = _resolve_combined_type(
self.connector,
type(self.lhs._output_field_or_none),
type(self.rhs._output_field_or_none),
)
if combined_type is None:
raise FieldError(
f"Cannot infer type of {self.connector!r} expression involving these "
f"types: {self.lhs.output_field.__class__.__name__}, "
f"{self.rhs.output_field.__class__.__name__}. You must set "
f"output_field."
)
return combined_type()
def as_sql(self, compiler, connection):
expressions = []
expression_params = []
sql, params = compiler.compile(self.lhs)
expressions.append(sql)
expression_params.extend(params)
sql, params = compiler.compile(self.rhs)
expressions.append(sql)
expression_params.extend(params)
# order of precedence
expression_wrapper = "(%s)"
sql = connection.ops.combine_expression(self.connector, expressions)
return expression_wrapper % sql, expression_params
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
lhs = self.lhs.resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
rhs = self.rhs.resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
if not isinstance(self, (DurationExpression, TemporalSubtraction)):
try:
lhs_type = lhs.output_field.get_internal_type()
except (AttributeError, FieldError):
lhs_type = None
try:
rhs_type = rhs.output_field.get_internal_type()
except (AttributeError, FieldError):
rhs_type = None
if "DurationField" in {lhs_type, rhs_type} and lhs_type != rhs_type:
return DurationExpression(
self.lhs, self.connector, self.rhs
).resolve_expression(
query,
allow_joins,
reuse,
summarize,
for_save,
)
datetime_fields = {"DateField", "DateTimeField", "TimeField"}
if (
self.connector == self.SUB
and lhs_type in datetime_fields
and lhs_type == rhs_type
):
return TemporalSubtraction(self.lhs, self.rhs).resolve_expression(
query,
allow_joins,
reuse,
summarize,
for_save,
)
c = self.copy()
c.is_summary = summarize
c.lhs = lhs
c.rhs = rhs
return c
class DurationExpression(CombinedExpression):
def compile(self, side, compiler, connection):
try:
output = side.output_field
except FieldError:
pass
else:
if output.get_internal_type() == "DurationField":
sql, params = compiler.compile(side)
return connection.ops.format_for_duration_arithmetic(sql), params
return compiler.compile(side)
def as_sql(self, compiler, connection):
if connection.features.has_native_duration_field:
return super().as_sql(compiler, connection)
connection.ops.check_expression_support(self)
expressions = []
expression_params = []
sql, params = self.compile(self.lhs, compiler, connection)
expressions.append(sql)
expression_params.extend(params)
sql, params = self.compile(self.rhs, compiler, connection)
expressions.append(sql)
expression_params.extend(params)
# order of precedence
expression_wrapper = "(%s)"
sql = connection.ops.combine_duration_expression(self.connector, expressions)
return expression_wrapper % sql, expression_params
def as_sqlite(self, compiler, connection, **extra_context):
sql, params = self.as_sql(compiler, connection, **extra_context)
if self.connector in {Combinable.MUL, Combinable.DIV}:
try:
lhs_type = self.lhs.output_field.get_internal_type()
rhs_type = self.rhs.output_field.get_internal_type()
except (AttributeError, FieldError):
pass
else:
allowed_fields = {
"DecimalField",
"DurationField",
"FloatField",
"IntegerField",
}
if lhs_type not in allowed_fields or rhs_type not in allowed_fields:
raise DatabaseError(
f"Invalid arguments for operator {self.connector}."
)
return sql, params
class TemporalSubtraction(CombinedExpression):
output_field = fields.DurationField()
def __init__(self, lhs, rhs):
super().__init__(lhs, self.SUB, rhs)
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
lhs = compiler.compile(self.lhs)
rhs = compiler.compile(self.rhs)
return connection.ops.subtract_temporals(
self.lhs.output_field.get_internal_type(), lhs, rhs
)
@deconstructible(path="django.db.models.F")
class F(Combinable):
"""An object capable of resolving references to existing query objects."""
def __init__(self, name):
"""
Arguments:
* name: the name of the field this expression references
"""
self.name = name
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self.name)
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
return query.resolve_ref(self.name, allow_joins, reuse, summarize)
def replace_expressions(self, replacements):
return replacements.get(self, self)
def asc(self, **kwargs):
return OrderBy(self, **kwargs)
def desc(self, **kwargs):
return OrderBy(self, descending=True, **kwargs)
def __eq__(self, other):
return self.__class__ == other.__class__ and self.name == other.name
def __hash__(self):
return hash(self.name)
def copy(self):
return copy.copy(self)
class ResolvedOuterRef(F):
"""
An object that contains a reference to an outer query.
In this case, the reference to the outer query has been resolved because
the inner query has been used as a subquery.
"""
contains_aggregate = False
contains_over_clause = False
def as_sql(self, *args, **kwargs):
raise ValueError(
"This queryset contains a reference to an outer query and may "
"only be used in a subquery."
)
def resolve_expression(self, *args, **kwargs):
col = super().resolve_expression(*args, **kwargs)
if col.contains_over_clause:
raise NotSupportedError(
f"Referencing outer query window expression is not supported: "
f"{self.name}."
)
# FIXME: Rename possibly_multivalued to multivalued and fix detection
# for non-multivalued JOINs (e.g. foreign key fields). This should take
# into account only many-to-many and one-to-many relationships.
col.possibly_multivalued = LOOKUP_SEP in self.name
return col
def relabeled_clone(self, relabels):
return self
def get_group_by_cols(self):
return []
class OuterRef(F):
contains_aggregate = False
def resolve_expression(self, *args, **kwargs):
if isinstance(self.name, self.__class__):
return self.name
return ResolvedOuterRef(self.name)
def relabeled_clone(self, relabels):
return self
@deconstructible(path="django.db.models.Func")
class Func(SQLiteNumericMixin, Expression):
"""An SQL function call."""
function = None
template = "%(function)s(%(expressions)s)"
arg_joiner = ", "
arity = None # The number of arguments the function accepts.
def __init__(self, *expressions, output_field=None, **extra):
if self.arity is not None and len(expressions) != self.arity:
raise TypeError(
"'%s' takes exactly %s %s (%s given)"
% (
self.__class__.__name__,
self.arity,
"argument" if self.arity == 1 else "arguments",
len(expressions),
)
)
super().__init__(output_field=output_field)
self.source_expressions = self._parse_expressions(*expressions)
self.extra = extra
def __repr__(self):
args = self.arg_joiner.join(str(arg) for arg in self.source_expressions)
extra = {**self.extra, **self._get_repr_options()}
if extra:
extra = ", ".join(
str(key) + "=" + str(val) for key, val in sorted(extra.items())
)
return "{}({}, {})".format(self.__class__.__name__, args, extra)
return "{}({})".format(self.__class__.__name__, args)
def _get_repr_options(self):
"""Return a dict of extra __init__() options to include in the repr."""
return {}
def get_source_expressions(self):
return self.source_expressions
def set_source_expressions(self, exprs):
self.source_expressions = exprs
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
c = self.copy()
c.is_summary = summarize
for pos, arg in enumerate(c.source_expressions):
c.source_expressions[pos] = arg.resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
return c
def as_sql(
self,
compiler,
connection,
function=None,
template=None,
arg_joiner=None,
**extra_context,
):
connection.ops.check_expression_support(self)
sql_parts = []
params = []
for arg in self.source_expressions:
try:
arg_sql, arg_params = compiler.compile(arg)
except EmptyResultSet:
empty_result_set_value = getattr(
arg, "empty_result_set_value", NotImplemented
)
if empty_result_set_value is NotImplemented:
raise
arg_sql, arg_params = compiler.compile(Value(empty_result_set_value))
except FullResultSet:
arg_sql, arg_params = compiler.compile(Value(True))
sql_parts.append(arg_sql)
params.extend(arg_params)
data = {**self.extra, **extra_context}
# Use the first supplied value in this order: the parameter to this
# method, a value supplied in __init__()'s **extra (the value in
# `data`), or the value defined on the class.
if function is not None:
data["function"] = function
else:
data.setdefault("function", self.function)
template = template or data.get("template", self.template)
arg_joiner = arg_joiner or data.get("arg_joiner", self.arg_joiner)
data["expressions"] = data["field"] = arg_joiner.join(sql_parts)
return template % data, params
def copy(self):
copy = super().copy()
copy.source_expressions = self.source_expressions[:]
copy.extra = self.extra.copy()
return copy
@deconstructible(path="django.db.models.Value")
class Value(SQLiteNumericMixin, Expression):
"""Represent a wrapped value as a node within an expression."""
# Provide a default value for `for_save` in order to allow unresolved
# instances to be compiled until a decision is taken in #25425.
for_save = False
def __init__(self, value, output_field=None):
"""
Arguments:
* value: the value this expression represents. The value will be
added into the sql parameter list and properly quoted.
* output_field: an instance of the model field type that this
expression will return, such as IntegerField() or CharField().
"""
super().__init__(output_field=output_field)
self.value = value
def __repr__(self):
return f"{self.__class__.__name__}({self.value!r})"
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
val = self.value
output_field = self._output_field_or_none
if output_field is not None:
if self.for_save:
val = output_field.get_db_prep_save(val, connection=connection)
else:
val = output_field.get_db_prep_value(val, connection=connection)
if hasattr(output_field, "get_placeholder"):
return output_field.get_placeholder(val, compiler, connection), [val]
if val is None:
# cx_Oracle does not always convert None to the appropriate
# NULL type (like in case expressions using numbers), so we
# use a literal SQL NULL
return "NULL", []
return "%s", [val]
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
c = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
c.for_save = for_save
return c
def get_group_by_cols(self):
return []
def _resolve_output_field(self):
if isinstance(self.value, str):
return fields.CharField()
if isinstance(self.value, bool):
return fields.BooleanField()
if isinstance(self.value, int):
return fields.IntegerField()
if isinstance(self.value, float):
return fields.FloatField()
if isinstance(self.value, datetime.datetime):
return fields.DateTimeField()
if isinstance(self.value, datetime.date):
return fields.DateField()
if isinstance(self.value, datetime.time):
return fields.TimeField()
if isinstance(self.value, datetime.timedelta):
return fields.DurationField()
if isinstance(self.value, Decimal):
return fields.DecimalField()
if isinstance(self.value, bytes):
return fields.BinaryField()
if isinstance(self.value, UUID):
return fields.UUIDField()
@property
def empty_result_set_value(self):
return self.value
class RawSQL(Expression):
def __init__(self, sql, params, output_field=None):
if output_field is None:
output_field = fields.Field()
self.sql, self.params = sql, params
super().__init__(output_field=output_field)
def __repr__(self):
return "{}({}, {})".format(self.__class__.__name__, self.sql, self.params)
def as_sql(self, compiler, connection):
return "(%s)" % self.sql, self.params
def get_group_by_cols(self):
return [self]
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
# Resolve parents fields used in raw SQL.
if query.model:
for parent in query.model._meta.get_parent_list():
for parent_field in parent._meta.local_fields:
_, column_name = parent_field.get_attname_column()
if column_name.lower() in self.sql.lower():
query.resolve_ref(
parent_field.name, allow_joins, reuse, summarize
)
break
return super().resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
class Star(Expression):
def __repr__(self):
return "'*'"
def as_sql(self, compiler, connection):
return "*", []
class Col(Expression):
contains_column_references = True
possibly_multivalued = False
def __init__(self, alias, target, output_field=None):
if output_field is None:
output_field = target
super().__init__(output_field=output_field)
self.alias, self.target = alias, target
def __repr__(self):
alias, target = self.alias, self.target
identifiers = (alias, str(target)) if alias else (str(target),)
return "{}({})".format(self.__class__.__name__, ", ".join(identifiers))
def as_sql(self, compiler, connection):
alias, column = self.alias, self.target.column
identifiers = (alias, column) if alias else (column,)
sql = ".".join(map(compiler.quote_name_unless_alias, identifiers))
return sql, []
def relabeled_clone(self, relabels):
if self.alias is None:
return self
return self.__class__(
relabels.get(self.alias, self.alias), self.target, self.output_field
)
def get_group_by_cols(self):
return [self]
def get_db_converters(self, connection):
if self.target == self.output_field:
return self.output_field.get_db_converters(connection)
return self.output_field.get_db_converters(
connection
) + self.target.get_db_converters(connection)
class Ref(Expression):
"""
Reference to column alias of the query. For example, Ref('sum_cost') in
qs.annotate(sum_cost=Sum('cost')) query.
"""
def __init__(self, refs, source):
super().__init__()
self.refs, self.source = refs, source
def __repr__(self):
return "{}({}, {})".format(self.__class__.__name__, self.refs, self.source)
def get_source_expressions(self):
return [self.source]
def set_source_expressions(self, exprs):
(self.source,) = exprs
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
# The sub-expression `source` has already been resolved, as this is
# just a reference to the name of `source`.
return self
def get_refs(self):
return {self.refs}
def relabeled_clone(self, relabels):
return self
def as_sql(self, compiler, connection):
return connection.ops.quote_name(self.refs), []
def get_group_by_cols(self):
return [self]
class ExpressionList(Func):
"""
An expression containing multiple expressions. Can be used to provide a
list of expressions as an argument to another expression, like a partition
clause.
"""
template = "%(expressions)s"
def __init__(self, *expressions, **extra):
if not expressions:
raise ValueError(
"%s requires at least one expression." % self.__class__.__name__
)
super().__init__(*expressions, **extra)
def __str__(self):
return self.arg_joiner.join(str(arg) for arg in self.source_expressions)
def as_sqlite(self, compiler, connection, **extra_context):
# Casting to numeric is unnecessary.
return self.as_sql(compiler, connection, **extra_context)
class OrderByList(Func):
template = "ORDER BY %(expressions)s"
def __init__(self, *expressions, **extra):
expressions = (
(
OrderBy(F(expr[1:]), descending=True)
if isinstance(expr, str) and expr[0] == "-"
else expr
)
for expr in expressions
)
super().__init__(*expressions, **extra)
def as_sql(self, *args, **kwargs):
if not self.source_expressions:
return "", ()
return super().as_sql(*args, **kwargs)
def get_group_by_cols(self):
group_by_cols = []
for order_by in self.get_source_expressions():
group_by_cols.extend(order_by.get_group_by_cols())
return group_by_cols
@deconstructible(path="django.db.models.ExpressionWrapper")
class ExpressionWrapper(SQLiteNumericMixin, Expression):
"""
An expression that can wrap another expression so that it can provide
extra context to the inner expression, such as the output_field.
"""
def __init__(self, expression, output_field):
super().__init__(output_field=output_field)
self.expression = expression
def set_source_expressions(self, exprs):
self.expression = exprs[0]
def get_source_expressions(self):
return [self.expression]
def get_group_by_cols(self):
if isinstance(self.expression, Expression):
expression = self.expression.copy()
expression.output_field = self.output_field
return expression.get_group_by_cols()
# For non-expressions e.g. an SQL WHERE clause, the entire
# `expression` must be included in the GROUP BY clause.
return super().get_group_by_cols()
def as_sql(self, compiler, connection):
return compiler.compile(self.expression)
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self.expression)
class NegatedExpression(ExpressionWrapper):
"""The logical negation of a conditional expression."""
def __init__(self, expression):
super().__init__(expression, output_field=fields.BooleanField())
def __invert__(self):
return self.expression.copy()
def as_sql(self, compiler, connection):
try:
sql, params = super().as_sql(compiler, connection)
except EmptyResultSet:
features = compiler.connection.features
if not features.supports_boolean_expr_in_select_clause:
return "1=1", ()
return compiler.compile(Value(True))
ops = compiler.connection.ops
# Some database backends (e.g. Oracle) don't allow EXISTS() and filters
# to be compared to another expression unless they're wrapped in a CASE
# WHEN.
if not ops.conditional_expression_supported_in_where_clause(self.expression):
return f"CASE WHEN {sql} = 0 THEN 1 ELSE 0 END", params
return f"NOT {sql}", params
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
resolved = super().resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
if not getattr(resolved.expression, "conditional", False):
raise TypeError("Cannot negate non-conditional expressions.")
return resolved
def select_format(self, compiler, sql, params):
# Wrap boolean expressions with a CASE WHEN expression if a database
# backend (e.g. Oracle) doesn't support boolean expression in SELECT or
# GROUP BY list.
expression_supported_in_where_clause = (
compiler.connection.ops.conditional_expression_supported_in_where_clause
)
if (
not compiler.connection.features.supports_boolean_expr_in_select_clause
# Avoid double wrapping.
and expression_supported_in_where_clause(self.expression)
):
sql = "CASE WHEN {} THEN 1 ELSE 0 END".format(sql)
return sql, params
@deconstructible(path="django.db.models.When")
class When(Expression):
template = "WHEN %(condition)s THEN %(result)s"
# This isn't a complete conditional expression, must be used in Case().
conditional = False
def __init__(self, condition=None, then=None, **lookups):
if lookups:
if condition is None:
condition, lookups = Q(**lookups), None
elif getattr(condition, "conditional", False):
condition, lookups = Q(condition, **lookups), None
if condition is None or not getattr(condition, "conditional", False) or lookups:
raise TypeError(
"When() supports a Q object, a boolean expression, or lookups "
"as a condition."
)
if isinstance(condition, Q) and not condition:
raise ValueError("An empty Q() can't be used as a When() condition.")
super().__init__(output_field=None)
self.condition = condition
self.result = self._parse_expressions(then)[0]
def __str__(self):
return "WHEN %r THEN %r" % (self.condition, self.result)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def get_source_expressions(self):
return [self.condition, self.result]
def set_source_expressions(self, exprs):
self.condition, self.result = exprs
def get_source_fields(self):
# We're only interested in the fields of the result expressions.
return [self.result._output_field_or_none]
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
c = self.copy()
c.is_summary = summarize
if hasattr(c.condition, "resolve_expression"):
c.condition = c.condition.resolve_expression(
query, allow_joins, reuse, summarize, False
)
c.result = c.result.resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
return c
def as_sql(self, compiler, connection, template=None, **extra_context):
connection.ops.check_expression_support(self)
template_params = extra_context
sql_params = []
condition_sql, condition_params = compiler.compile(self.condition)
template_params["condition"] = condition_sql
result_sql, result_params = compiler.compile(self.result)
template_params["result"] = result_sql
template = template or self.template
return template % template_params, (
*sql_params,
*condition_params,
*result_params,
)
def get_group_by_cols(self):
# This is not a complete expression and cannot be used in GROUP BY.
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
@deconstructible(path="django.db.models.Case")
class Case(SQLiteNumericMixin, Expression):
"""
An SQL searched CASE expression:
CASE
WHEN n > 0
THEN 'positive'
WHEN n < 0
THEN 'negative'
ELSE 'zero'
END
"""
template = "CASE %(cases)s ELSE %(default)s END"
case_joiner = " "
def __init__(self, *cases, default=None, output_field=None, **extra):
if not all(isinstance(case, When) for case in cases):
raise TypeError("Positional arguments must all be When objects.")
super().__init__(output_field)
self.cases = list(cases)
self.default = self._parse_expressions(default)[0]
self.extra = extra
def __str__(self):
return "CASE %s, ELSE %r" % (
", ".join(str(c) for c in self.cases),
self.default,
)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def get_source_expressions(self):
return self.cases + [self.default]
def set_source_expressions(self, exprs):
*self.cases, self.default = exprs
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
c = self.copy()
c.is_summary = summarize
for pos, case in enumerate(c.cases):
c.cases[pos] = case.resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
c.default = c.default.resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
return c
def copy(self):
c = super().copy()
c.cases = c.cases[:]
return c
def as_sql(
self, compiler, connection, template=None, case_joiner=None, **extra_context
):
connection.ops.check_expression_support(self)
if not self.cases:
return compiler.compile(self.default)
template_params = {**self.extra, **extra_context}
case_parts = []
sql_params = []
default_sql, default_params = compiler.compile(self.default)
for case in self.cases:
try:
case_sql, case_params = compiler.compile(case)
except EmptyResultSet:
continue
except FullResultSet:
default_sql, default_params = compiler.compile(case.result)
break
case_parts.append(case_sql)
sql_params.extend(case_params)
if not case_parts:
return default_sql, default_params
case_joiner = case_joiner or self.case_joiner
template_params["cases"] = case_joiner.join(case_parts)
template_params["default"] = default_sql
sql_params.extend(default_params)
template = template or template_params.get("template", self.template)
sql = template % template_params
if self._output_field_or_none is not None:
sql = connection.ops.unification_cast_sql(self.output_field) % sql
return sql, sql_params
def get_group_by_cols(self):
if not self.cases:
return self.default.get_group_by_cols()
return super().get_group_by_cols()
class Subquery(BaseExpression, Combinable):
"""
An explicit subquery. It may contain OuterRef() references to the outer
query which will be resolved when it is applied to that query.
"""
template = "(%(subquery)s)"
contains_aggregate = False
empty_result_set_value = None
subquery = True
def __init__(self, queryset, output_field=None, **extra):
# Allow the usage of both QuerySet and sql.Query objects.
self.query = getattr(queryset, "query", queryset).clone()
self.query.subquery = True
self.extra = extra
super().__init__(output_field)
def get_source_expressions(self):
return [self.query]
def set_source_expressions(self, exprs):
self.query = exprs[0]
def _resolve_output_field(self):
return self.query.output_field
def copy(self):
clone = super().copy()
clone.query = clone.query.clone()
return clone
@property
def external_aliases(self):
return self.query.external_aliases
def get_external_cols(self):
return self.query.get_external_cols()
def as_sql(self, compiler, connection, template=None, **extra_context):
connection.ops.check_expression_support(self)
template_params = {**self.extra, **extra_context}
subquery_sql, sql_params = self.query.as_sql(compiler, connection)
template_params["subquery"] = subquery_sql[1:-1]
template = template or template_params.get("template", self.template)
sql = template % template_params
return sql, sql_params
def get_group_by_cols(self):
return self.query.get_group_by_cols(wrapper=self)
class Exists(Subquery):
template = "EXISTS(%(subquery)s)"
output_field = fields.BooleanField()
empty_result_set_value = False
def __init__(self, queryset, **kwargs):
super().__init__(queryset, **kwargs)
self.query = self.query.exists()
def select_format(self, compiler, sql, params):
# Wrap EXISTS() with a CASE WHEN expression if a database backend
# (e.g. Oracle) doesn't support boolean expression in SELECT or GROUP
# BY list.
if not compiler.connection.features.supports_boolean_expr_in_select_clause:
sql = "CASE WHEN {} THEN 1 ELSE 0 END".format(sql)
return sql, params
@deconstructible(path="django.db.models.OrderBy")
class OrderBy(Expression):
template = "%(expression)s %(ordering)s"
conditional = False
def __init__(self, expression, descending=False, nulls_first=None, nulls_last=None):
if nulls_first and nulls_last:
raise ValueError("nulls_first and nulls_last are mutually exclusive")
if nulls_first is False or nulls_last is False:
# When the deprecation ends, replace with:
# raise ValueError(
# "nulls_first and nulls_last values must be True or None."
# )
warnings.warn(
"Passing nulls_first=False or nulls_last=False is deprecated, use None "
"instead.",
RemovedInDjango50Warning,
stacklevel=2,
)
self.nulls_first = nulls_first
self.nulls_last = nulls_last
self.descending = descending
if not hasattr(expression, "resolve_expression"):
raise ValueError("expression must be an expression type")
self.expression = expression
def __repr__(self):
return "{}({}, descending={})".format(
self.__class__.__name__, self.expression, self.descending
)
def set_source_expressions(self, exprs):
self.expression = exprs[0]
def get_source_expressions(self):
return [self.expression]
def as_sql(self, compiler, connection, template=None, **extra_context):
template = template or self.template
if connection.features.supports_order_by_nulls_modifier:
if self.nulls_last:
template = "%s NULLS LAST" % template
elif self.nulls_first:
template = "%s NULLS FIRST" % template
else:
if self.nulls_last and not (
self.descending and connection.features.order_by_nulls_first
):
template = "%%(expression)s IS NULL, %s" % template
elif self.nulls_first and not (
not self.descending and connection.features.order_by_nulls_first
):
template = "%%(expression)s IS NOT NULL, %s" % template
connection.ops.check_expression_support(self)
expression_sql, params = compiler.compile(self.expression)
placeholders = {
"expression": expression_sql,
"ordering": "DESC" if self.descending else "ASC",
**extra_context,
}
params *= template.count("%(expression)s")
return (template % placeholders).rstrip(), params
def as_oracle(self, compiler, connection):
# Oracle doesn't allow ORDER BY EXISTS() or filters unless it's wrapped
# in a CASE WHEN.
if connection.ops.conditional_expression_supported_in_where_clause(
self.expression
):
copy = self.copy()
copy.expression = Case(
When(self.expression, then=True),
default=False,
)
return copy.as_sql(compiler, connection)
return self.as_sql(compiler, connection)
def get_group_by_cols(self):
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
def reverse_ordering(self):
self.descending = not self.descending
if self.nulls_first:
self.nulls_last = True
self.nulls_first = None
elif self.nulls_last:
self.nulls_first = True
self.nulls_last = None
return self
def asc(self):
self.descending = False
def desc(self):
self.descending = True
class Window(SQLiteNumericMixin, Expression):
template = "%(expression)s OVER (%(window)s)"
# Although the main expression may either be an aggregate or an
# expression with an aggregate function, the GROUP BY that will
# be introduced in the query as a result is not desired.
contains_aggregate = False
contains_over_clause = True
def __init__(
self,
expression,
partition_by=None,
order_by=None,
frame=None,
output_field=None,
):
self.partition_by = partition_by
self.order_by = order_by
self.frame = frame
if not getattr(expression, "window_compatible", False):
raise ValueError(
"Expression '%s' isn't compatible with OVER clauses."
% expression.__class__.__name__
)
if self.partition_by is not None:
if not isinstance(self.partition_by, (tuple, list)):
self.partition_by = (self.partition_by,)
self.partition_by = ExpressionList(*self.partition_by)
if self.order_by is not None:
if isinstance(self.order_by, (list, tuple)):
self.order_by = OrderByList(*self.order_by)
elif isinstance(self.order_by, (BaseExpression, str)):
self.order_by = OrderByList(self.order_by)
else:
raise ValueError(
"Window.order_by must be either a string reference to a "
"field, an expression, or a list or tuple of them."
)
super().__init__(output_field=output_field)
self.source_expression = self._parse_expressions(expression)[0]
def _resolve_output_field(self):
return self.source_expression.output_field
def get_source_expressions(self):
return [self.source_expression, self.partition_by, self.order_by, self.frame]
def set_source_expressions(self, exprs):
self.source_expression, self.partition_by, self.order_by, self.frame = exprs
def as_sql(self, compiler, connection, template=None):
connection.ops.check_expression_support(self)
if not connection.features.supports_over_clause:
raise NotSupportedError("This backend does not support window expressions.")
expr_sql, params = compiler.compile(self.source_expression)
window_sql, window_params = [], ()
if self.partition_by is not None:
sql_expr, sql_params = self.partition_by.as_sql(
compiler=compiler,
connection=connection,
template="PARTITION BY %(expressions)s",
)
window_sql.append(sql_expr)
window_params += tuple(sql_params)
if self.order_by is not None:
order_sql, order_params = compiler.compile(self.order_by)
window_sql.append(order_sql)
window_params += tuple(order_params)
if self.frame:
frame_sql, frame_params = compiler.compile(self.frame)
window_sql.append(frame_sql)
window_params += tuple(frame_params)
template = template or self.template
return (
template % {"expression": expr_sql, "window": " ".join(window_sql).strip()},
(*params, *window_params),
)
def as_sqlite(self, compiler, connection):
if isinstance(self.output_field, fields.DecimalField):
# Casting to numeric must be outside of the window expression.
copy = self.copy()
source_expressions = copy.get_source_expressions()
source_expressions[0].output_field = fields.FloatField()
copy.set_source_expressions(source_expressions)
return super(Window, copy).as_sqlite(compiler, connection)
return self.as_sql(compiler, connection)
def __str__(self):
return "{} OVER ({}{}{})".format(
str(self.source_expression),
"PARTITION BY " + str(self.partition_by) if self.partition_by else "",
str(self.order_by or ""),
str(self.frame or ""),
)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def get_group_by_cols(self):
group_by_cols = []
if self.partition_by:
group_by_cols.extend(self.partition_by.get_group_by_cols())
if self.order_by is not None:
group_by_cols.extend(self.order_by.get_group_by_cols())
return group_by_cols
class WindowFrame(Expression):
"""
Model the frame clause in window expressions. There are two types of frame
clauses which are subclasses, however, all processing and validation (by no
means intended to be complete) is done here. Thus, providing an end for a
frame is optional (the default is UNBOUNDED FOLLOWING, which is the last
row in the frame).
"""
template = "%(frame_type)s BETWEEN %(start)s AND %(end)s"
def __init__(self, start=None, end=None):
self.start = Value(start)
self.end = Value(end)
def set_source_expressions(self, exprs):
self.start, self.end = exprs
def get_source_expressions(self):
return [self.start, self.end]
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
start, end = self.window_frame_start_end(
connection, self.start.value, self.end.value
)
return (
self.template
% {
"frame_type": self.frame_type,
"start": start,
"end": end,
},
[],
)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def get_group_by_cols(self):
return []
def __str__(self):
if self.start.value is not None and self.start.value < 0:
start = "%d %s" % (abs(self.start.value), connection.ops.PRECEDING)
elif self.start.value is not None and self.start.value == 0:
start = connection.ops.CURRENT_ROW
else:
start = connection.ops.UNBOUNDED_PRECEDING
if self.end.value is not None and self.end.value > 0:
end = "%d %s" % (self.end.value, connection.ops.FOLLOWING)
elif self.end.value is not None and self.end.value == 0:
end = connection.ops.CURRENT_ROW
else:
end = connection.ops.UNBOUNDED_FOLLOWING
return self.template % {
"frame_type": self.frame_type,
"start": start,
"end": end,
}
def window_frame_start_end(self, connection, start, end):
raise NotImplementedError("Subclasses must implement window_frame_start_end().")
class RowRange(WindowFrame):
frame_type = "ROWS"
def window_frame_start_end(self, connection, start, end):
return connection.ops.window_frame_rows_start_end(start, end)
class ValueRange(WindowFrame):
frame_type = "RANGE"
def window_frame_start_end(self, connection, start, end):
return connection.ops.window_frame_range_start_end(start, end)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/expressions.py
|
Python
|
mit
| 64,809 |
import collections.abc
import copy
import datetime
import decimal
import operator
import uuid
import warnings
from base64 import b64decode, b64encode
from functools import partialmethod, total_ordering
from django import forms
from django.apps import apps
from django.conf import settings
from django.core import checks, exceptions, validators
from django.db import connection, connections, router
from django.db.models.constants import LOOKUP_SEP
from django.db.models.query_utils import DeferredAttribute, RegisterLookupMixin
from django.utils import timezone
from django.utils.datastructures import DictWrapper
from django.utils.dateparse import (
parse_date,
parse_datetime,
parse_duration,
parse_time,
)
from django.utils.duration import duration_microseconds, duration_string
from django.utils.functional import Promise, cached_property
from django.utils.ipv6 import clean_ipv6_address
from django.utils.itercompat import is_iterable
from django.utils.text import capfirst
from django.utils.translation import gettext_lazy as _
__all__ = [
"AutoField",
"BLANK_CHOICE_DASH",
"BigAutoField",
"BigIntegerField",
"BinaryField",
"BooleanField",
"CharField",
"CommaSeparatedIntegerField",
"DateField",
"DateTimeField",
"DecimalField",
"DurationField",
"EmailField",
"Empty",
"Field",
"FilePathField",
"FloatField",
"GenericIPAddressField",
"IPAddressField",
"IntegerField",
"NOT_PROVIDED",
"NullBooleanField",
"PositiveBigIntegerField",
"PositiveIntegerField",
"PositiveSmallIntegerField",
"SlugField",
"SmallAutoField",
"SmallIntegerField",
"TextField",
"TimeField",
"URLField",
"UUIDField",
]
class Empty:
pass
class NOT_PROVIDED:
pass
# The values to use for "blank" in SelectFields. Will be appended to the start
# of most "choices" lists.
BLANK_CHOICE_DASH = [("", "---------")]
def _load_field(app_label, model_name, field_name):
return apps.get_model(app_label, model_name)._meta.get_field(field_name)
# A guide to Field parameters:
#
# * name: The name of the field specified in the model.
# * attname: The attribute to use on the model object. This is the same as
# "name", except in the case of ForeignKeys, where "_id" is
# appended.
# * db_column: The db_column specified in the model (or None).
# * column: The database column for this field. This is the same as
# "attname", except if db_column is specified.
#
# Code that introspects values, or does other dynamic things, should use
# attname. For example, this gets the primary key value of object "obj":
#
# getattr(obj, opts.pk.attname)
def _empty(of_cls):
new = Empty()
new.__class__ = of_cls
return new
def return_None():
return None
@total_ordering
class Field(RegisterLookupMixin):
"""Base class for all field types"""
# Designates whether empty strings fundamentally are allowed at the
# database level.
empty_strings_allowed = True
empty_values = list(validators.EMPTY_VALUES)
# These track each time a Field instance is created. Used to retain order.
# The auto_creation_counter is used for fields that Django implicitly
# creates, creation_counter is used for all user-specified fields.
creation_counter = 0
auto_creation_counter = -1
default_validators = [] # Default set of validators
default_error_messages = {
"invalid_choice": _("Value %(value)r is not a valid choice."),
"null": _("This field cannot be null."),
"blank": _("This field cannot be blank."),
"unique": _("%(model_name)s with this %(field_label)s already exists."),
"unique_for_date": _(
# Translators: The 'lookup_type' is one of 'date', 'year' or
# 'month'. Eg: "Title must be unique for pub_date year"
"%(field_label)s must be unique for "
"%(date_field_label)s %(lookup_type)s."
),
}
system_check_deprecated_details = None
system_check_removed_details = None
# Attributes that don't affect a column definition.
# These attributes are ignored when altering the field.
non_db_attrs = (
"blank",
"choices",
"db_column",
"editable",
"error_messages",
"help_text",
"limit_choices_to",
# Database-level options are not supported, see #21961.
"on_delete",
"related_name",
"related_query_name",
"validators",
"verbose_name",
)
# Field flags
hidden = False
many_to_many = None
many_to_one = None
one_to_many = None
one_to_one = None
related_model = None
descriptor_class = DeferredAttribute
# Generic field type description, usually overridden by subclasses
def _description(self):
return _("Field of type: %(field_type)s") % {
"field_type": self.__class__.__name__
}
description = property(_description)
def __init__(
self,
verbose_name=None,
name=None,
primary_key=False,
max_length=None,
unique=False,
blank=False,
null=False,
db_index=False,
rel=None,
default=NOT_PROVIDED,
editable=True,
serialize=True,
unique_for_date=None,
unique_for_month=None,
unique_for_year=None,
choices=None,
help_text="",
db_column=None,
db_tablespace=None,
auto_created=False,
validators=(),
error_messages=None,
db_comment=None,
):
self.name = name
self.verbose_name = verbose_name # May be set by set_attributes_from_name
self._verbose_name = verbose_name # Store original for deconstruction
self.primary_key = primary_key
self.max_length, self._unique = max_length, unique
self.blank, self.null = blank, null
self.remote_field = rel
self.is_relation = self.remote_field is not None
self.default = default
self.editable = editable
self.serialize = serialize
self.unique_for_date = unique_for_date
self.unique_for_month = unique_for_month
self.unique_for_year = unique_for_year
if isinstance(choices, collections.abc.Iterator):
choices = list(choices)
self.choices = choices
self.help_text = help_text
self.db_index = db_index
self.db_column = db_column
self.db_comment = db_comment
self._db_tablespace = db_tablespace
self.auto_created = auto_created
# Adjust the appropriate creation counter, and save our local copy.
if auto_created:
self.creation_counter = Field.auto_creation_counter
Field.auto_creation_counter -= 1
else:
self.creation_counter = Field.creation_counter
Field.creation_counter += 1
self._validators = list(validators) # Store for deconstruction later
self._error_messages = error_messages # Store for deconstruction later
def __str__(self):
"""
Return "app_label.model_label.field_name" for fields attached to
models.
"""
if not hasattr(self, "model"):
return super().__str__()
model = self.model
return "%s.%s" % (model._meta.label, self.name)
def __repr__(self):
"""Display the module, class, and name of the field."""
path = "%s.%s" % (self.__class__.__module__, self.__class__.__qualname__)
name = getattr(self, "name", None)
if name is not None:
return "<%s: %s>" % (path, name)
return "<%s>" % path
def check(self, **kwargs):
return [
*self._check_field_name(),
*self._check_choices(),
*self._check_db_index(),
*self._check_db_comment(**kwargs),
*self._check_null_allowed_for_primary_keys(),
*self._check_backend_specific_checks(**kwargs),
*self._check_validators(),
*self._check_deprecation_details(),
]
def _check_field_name(self):
"""
Check if field name is valid, i.e. 1) does not end with an
underscore, 2) does not contain "__" and 3) is not "pk".
"""
if self.name.endswith("_"):
return [
checks.Error(
"Field names must not end with an underscore.",
obj=self,
id="fields.E001",
)
]
elif LOOKUP_SEP in self.name:
return [
checks.Error(
'Field names must not contain "%s".' % LOOKUP_SEP,
obj=self,
id="fields.E002",
)
]
elif self.name == "pk":
return [
checks.Error(
"'pk' is a reserved word that cannot be used as a field name.",
obj=self,
id="fields.E003",
)
]
else:
return []
@classmethod
def _choices_is_value(cls, value):
return isinstance(value, (str, Promise)) or not is_iterable(value)
def _check_choices(self):
if not self.choices:
return []
if not is_iterable(self.choices) or isinstance(self.choices, str):
return [
checks.Error(
"'choices' must be an iterable (e.g., a list or tuple).",
obj=self,
id="fields.E004",
)
]
choice_max_length = 0
# Expect [group_name, [value, display]]
for choices_group in self.choices:
try:
group_name, group_choices = choices_group
except (TypeError, ValueError):
# Containing non-pairs
break
try:
if not all(
self._choices_is_value(value) and self._choices_is_value(human_name)
for value, human_name in group_choices
):
break
if self.max_length is not None and group_choices:
choice_max_length = max(
[
choice_max_length,
*(
len(value)
for value, _ in group_choices
if isinstance(value, str)
),
]
)
except (TypeError, ValueError):
# No groups, choices in the form [value, display]
value, human_name = group_name, group_choices
if not self._choices_is_value(value) or not self._choices_is_value(
human_name
):
break
if self.max_length is not None and isinstance(value, str):
choice_max_length = max(choice_max_length, len(value))
# Special case: choices=['ab']
if isinstance(choices_group, str):
break
else:
if self.max_length is not None and choice_max_length > self.max_length:
return [
checks.Error(
"'max_length' is too small to fit the longest value "
"in 'choices' (%d characters)." % choice_max_length,
obj=self,
id="fields.E009",
),
]
return []
return [
checks.Error(
"'choices' must be an iterable containing "
"(actual value, human readable name) tuples.",
obj=self,
id="fields.E005",
)
]
def _check_db_index(self):
if self.db_index not in (None, True, False):
return [
checks.Error(
"'db_index' must be None, True or False.",
obj=self,
id="fields.E006",
)
]
else:
return []
def _check_db_comment(self, databases=None, **kwargs):
if not self.db_comment or not databases:
return []
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not (
connection.features.supports_comments
or "supports_comments" in self.model._meta.required_db_features
):
errors.append(
checks.Warning(
f"{connection.display_name} does not support comments on "
f"columns (db_comment).",
obj=self,
id="fields.W163",
)
)
return errors
def _check_null_allowed_for_primary_keys(self):
if (
self.primary_key
and self.null
and not connection.features.interprets_empty_strings_as_nulls
):
# We cannot reliably check this for backends like Oracle which
# consider NULL and '' to be equal (and thus set up
# character-based fields a little differently).
return [
checks.Error(
"Primary keys must not have null=True.",
hint=(
"Set null=False on the field, or "
"remove primary_key=True argument."
),
obj=self,
id="fields.E007",
)
]
else:
return []
def _check_backend_specific_checks(self, databases=None, **kwargs):
if databases is None:
return []
errors = []
for alias in databases:
if router.allow_migrate_model(alias, self.model):
errors.extend(connections[alias].validation.check_field(self, **kwargs))
return errors
def _check_validators(self):
errors = []
for i, validator in enumerate(self.validators):
if not callable(validator):
errors.append(
checks.Error(
"All 'validators' must be callable.",
hint=(
"validators[{i}] ({repr}) isn't a function or "
"instance of a validator class.".format(
i=i,
repr=repr(validator),
)
),
obj=self,
id="fields.E008",
)
)
return errors
def _check_deprecation_details(self):
if self.system_check_removed_details is not None:
return [
checks.Error(
self.system_check_removed_details.get(
"msg",
"%s has been removed except for support in historical "
"migrations." % self.__class__.__name__,
),
hint=self.system_check_removed_details.get("hint"),
obj=self,
id=self.system_check_removed_details.get("id", "fields.EXXX"),
)
]
elif self.system_check_deprecated_details is not None:
return [
checks.Warning(
self.system_check_deprecated_details.get(
"msg", "%s has been deprecated." % self.__class__.__name__
),
hint=self.system_check_deprecated_details.get("hint"),
obj=self,
id=self.system_check_deprecated_details.get("id", "fields.WXXX"),
)
]
return []
def get_col(self, alias, output_field=None):
if alias == self.model._meta.db_table and (
output_field is None or output_field == self
):
return self.cached_col
from django.db.models.expressions import Col
return Col(alias, self, output_field)
@cached_property
def cached_col(self):
from django.db.models.expressions import Col
return Col(self.model._meta.db_table, self)
def select_format(self, compiler, sql, params):
"""
Custom format for select clauses. For example, GIS columns need to be
selected as AsText(table.col) on MySQL as the table.col data can't be
used by Django.
"""
return sql, params
def deconstruct(self):
"""
Return enough information to recreate the field as a 4-tuple:
* The name of the field on the model, if contribute_to_class() has
been run.
* The import path of the field, including the class, e.g.
django.db.models.IntegerField. This should be the most portable
version, so less specific may be better.
* A list of positional arguments.
* A dict of keyword arguments.
Note that the positional or keyword arguments must contain values of
the following types (including inner values of collection types):
* None, bool, str, int, float, complex, set, frozenset, list, tuple,
dict
* UUID
* datetime.datetime (naive), datetime.date
* top-level classes, top-level functions - will be referenced by their
full import path
* Storage instances - these have their own deconstruct() method
This is because the values here must be serialized into a text format
(possibly new Python code, possibly JSON) and these are the only types
with encoding handlers defined.
There's no need to return the exact way the field was instantiated this
time, just ensure that the resulting field is the same - prefer keyword
arguments over positional ones, and omit parameters with their default
values.
"""
# Short-form way of fetching all the default parameters
keywords = {}
possibles = {
"verbose_name": None,
"primary_key": False,
"max_length": None,
"unique": False,
"blank": False,
"null": False,
"db_index": False,
"default": NOT_PROVIDED,
"editable": True,
"serialize": True,
"unique_for_date": None,
"unique_for_month": None,
"unique_for_year": None,
"choices": None,
"help_text": "",
"db_column": None,
"db_comment": None,
"db_tablespace": None,
"auto_created": False,
"validators": [],
"error_messages": None,
}
attr_overrides = {
"unique": "_unique",
"error_messages": "_error_messages",
"validators": "_validators",
"verbose_name": "_verbose_name",
"db_tablespace": "_db_tablespace",
}
equals_comparison = {"choices", "validators"}
for name, default in possibles.items():
value = getattr(self, attr_overrides.get(name, name))
# Unroll anything iterable for choices into a concrete list
if name == "choices" and isinstance(value, collections.abc.Iterable):
value = list(value)
# Do correct kind of comparison
if name in equals_comparison:
if value != default:
keywords[name] = value
else:
if value is not default:
keywords[name] = value
# Work out path - we shorten it for known Django core fields
path = "%s.%s" % (self.__class__.__module__, self.__class__.__qualname__)
if path.startswith("django.db.models.fields.related"):
path = path.replace("django.db.models.fields.related", "django.db.models")
elif path.startswith("django.db.models.fields.files"):
path = path.replace("django.db.models.fields.files", "django.db.models")
elif path.startswith("django.db.models.fields.json"):
path = path.replace("django.db.models.fields.json", "django.db.models")
elif path.startswith("django.db.models.fields.proxy"):
path = path.replace("django.db.models.fields.proxy", "django.db.models")
elif path.startswith("django.db.models.fields"):
path = path.replace("django.db.models.fields", "django.db.models")
# Return basic info - other fields should override this.
return (self.name, path, [], keywords)
def clone(self):
"""
Uses deconstruct() to clone a new copy of this Field.
Will not preserve any class attachments/attribute names.
"""
name, path, args, kwargs = self.deconstruct()
return self.__class__(*args, **kwargs)
def __eq__(self, other):
# Needed for @total_ordering
if isinstance(other, Field):
return self.creation_counter == other.creation_counter and getattr(
self, "model", None
) == getattr(other, "model", None)
return NotImplemented
def __lt__(self, other):
# This is needed because bisect does not take a comparison function.
# Order by creation_counter first for backward compatibility.
if isinstance(other, Field):
if (
self.creation_counter != other.creation_counter
or not hasattr(self, "model")
and not hasattr(other, "model")
):
return self.creation_counter < other.creation_counter
elif hasattr(self, "model") != hasattr(other, "model"):
return not hasattr(self, "model") # Order no-model fields first
else:
# creation_counter's are equal, compare only models.
return (self.model._meta.app_label, self.model._meta.model_name) < (
other.model._meta.app_label,
other.model._meta.model_name,
)
return NotImplemented
def __hash__(self):
return hash(self.creation_counter)
def __deepcopy__(self, memodict):
# We don't have to deepcopy very much here, since most things are not
# intended to be altered after initial creation.
obj = copy.copy(self)
if self.remote_field:
obj.remote_field = copy.copy(self.remote_field)
if hasattr(self.remote_field, "field") and self.remote_field.field is self:
obj.remote_field.field = obj
memodict[id(self)] = obj
return obj
def __copy__(self):
# We need to avoid hitting __reduce__, so define this
# slightly weird copy construct.
obj = Empty()
obj.__class__ = self.__class__
obj.__dict__ = self.__dict__.copy()
return obj
def __reduce__(self):
"""
Pickling should return the model._meta.fields instance of the field,
not a new copy of that field. So, use the app registry to load the
model and then the field back.
"""
if not hasattr(self, "model"):
# Fields are sometimes used without attaching them to models (for
# example in aggregation). In this case give back a plain field
# instance. The code below will create a new empty instance of
# class self.__class__, then update its dict with self.__dict__
# values - so, this is very close to normal pickle.
state = self.__dict__.copy()
# The _get_default cached_property can't be pickled due to lambda
# usage.
state.pop("_get_default", None)
return _empty, (self.__class__,), state
return _load_field, (
self.model._meta.app_label,
self.model._meta.object_name,
self.name,
)
def get_pk_value_on_save(self, instance):
"""
Hook to generate new PK values on save. This method is called when
saving instances with no primary key value set. If this method returns
something else than None, then the returned value is used when saving
the new instance.
"""
if self.default:
return self.get_default()
return None
def to_python(self, value):
"""
Convert the input value into the expected Python data type, raising
django.core.exceptions.ValidationError if the data can't be converted.
Return the converted value. Subclasses should override this.
"""
return value
@cached_property
def error_messages(self):
messages = {}
for c in reversed(self.__class__.__mro__):
messages.update(getattr(c, "default_error_messages", {}))
messages.update(self._error_messages or {})
return messages
@cached_property
def validators(self):
"""
Some validators can't be created at field initialization time.
This method provides a way to delay their creation until required.
"""
return [*self.default_validators, *self._validators]
def run_validators(self, value):
if value in self.empty_values:
return
errors = []
for v in self.validators:
try:
v(value)
except exceptions.ValidationError as e:
if hasattr(e, "code") and e.code in self.error_messages:
e.message = self.error_messages[e.code]
errors.extend(e.error_list)
if errors:
raise exceptions.ValidationError(errors)
def validate(self, value, model_instance):
"""
Validate value and raise ValidationError if necessary. Subclasses
should override this to provide validation logic.
"""
if not self.editable:
# Skip validation for non-editable fields.
return
if self.choices is not None and value not in self.empty_values:
for option_key, option_value in self.choices:
if isinstance(option_value, (list, tuple)):
# This is an optgroup, so look inside the group for
# options.
for optgroup_key, optgroup_value in option_value:
if value == optgroup_key:
return
elif value == option_key:
return
raise exceptions.ValidationError(
self.error_messages["invalid_choice"],
code="invalid_choice",
params={"value": value},
)
if value is None and not self.null:
raise exceptions.ValidationError(self.error_messages["null"], code="null")
if not self.blank and value in self.empty_values:
raise exceptions.ValidationError(self.error_messages["blank"], code="blank")
def clean(self, value, model_instance):
"""
Convert the value's type and run validation. Validation errors
from to_python() and validate() are propagated. Return the correct
value if no error is raised.
"""
value = self.to_python(value)
self.validate(value, model_instance)
self.run_validators(value)
return value
def db_type_parameters(self, connection):
return DictWrapper(self.__dict__, connection.ops.quote_name, "qn_")
def db_check(self, connection):
"""
Return the database column check constraint for this field, for the
provided connection. Works the same way as db_type() for the case that
get_internal_type() does not map to a preexisting model field.
"""
data = self.db_type_parameters(connection)
try:
return (
connection.data_type_check_constraints[self.get_internal_type()] % data
)
except KeyError:
return None
def db_type(self, connection):
"""
Return the database column data type for this field, for the provided
connection.
"""
# The default implementation of this method looks at the
# backend-specific data_types dictionary, looking up the field by its
# "internal type".
#
# A Field class can implement the get_internal_type() method to specify
# which *preexisting* Django Field class it's most similar to -- i.e.,
# a custom field might be represented by a TEXT column type, which is
# the same as the TextField Django field type, which means the custom
# field's get_internal_type() returns 'TextField'.
#
# But the limitation of the get_internal_type() / data_types approach
# is that it cannot handle database column types that aren't already
# mapped to one of the built-in Django field types. In this case, you
# can implement db_type() instead of get_internal_type() to specify
# exactly which wacky database column type you want to use.
data = self.db_type_parameters(connection)
try:
column_type = connection.data_types[self.get_internal_type()]
except KeyError:
return None
else:
# column_type is either a single-parameter function or a string.
if callable(column_type):
return column_type(data)
return column_type % data
def rel_db_type(self, connection):
"""
Return the data type that a related field pointing to this field should
use. For example, this method is called by ForeignKey and OneToOneField
to determine its data type.
"""
return self.db_type(connection)
def cast_db_type(self, connection):
"""Return the data type to use in the Cast() function."""
db_type = connection.ops.cast_data_types.get(self.get_internal_type())
if db_type:
return db_type % self.db_type_parameters(connection)
return self.db_type(connection)
def db_parameters(self, connection):
"""
Extension of db_type(), providing a range of different return values
(type, checks). This will look at db_type(), allowing custom model
fields to override it.
"""
type_string = self.db_type(connection)
check_string = self.db_check(connection)
return {
"type": type_string,
"check": check_string,
}
def db_type_suffix(self, connection):
return connection.data_types_suffix.get(self.get_internal_type())
def get_db_converters(self, connection):
if hasattr(self, "from_db_value"):
return [self.from_db_value]
return []
@property
def unique(self):
return self._unique or self.primary_key
@property
def db_tablespace(self):
return self._db_tablespace or settings.DEFAULT_INDEX_TABLESPACE
@property
def db_returning(self):
"""
Private API intended only to be used by Django itself. Currently only
the PostgreSQL backend supports returning multiple fields on a model.
"""
return False
def set_attributes_from_name(self, name):
self.name = self.name or name
self.attname, self.column = self.get_attname_column()
self.concrete = self.column is not None
if self.verbose_name is None and self.name:
self.verbose_name = self.name.replace("_", " ")
def contribute_to_class(self, cls, name, private_only=False):
"""
Register the field with the model class it belongs to.
If private_only is True, create a separate instance of this field
for every subclass of cls, even if cls is not an abstract model.
"""
self.set_attributes_from_name(name)
self.model = cls
cls._meta.add_field(self, private=private_only)
if self.column:
setattr(cls, self.attname, self.descriptor_class(self))
if self.choices is not None:
# Don't override a get_FOO_display() method defined explicitly on
# this class, but don't check methods derived from inheritance, to
# allow overriding inherited choices. For more complex inheritance
# structures users should override contribute_to_class().
if "get_%s_display" % self.name not in cls.__dict__:
setattr(
cls,
"get_%s_display" % self.name,
partialmethod(cls._get_FIELD_display, field=self),
)
def get_filter_kwargs_for_object(self, obj):
"""
Return a dict that when passed as kwargs to self.model.filter(), would
yield all instances having the same value for this field as obj has.
"""
return {self.name: getattr(obj, self.attname)}
def get_attname(self):
return self.name
def get_attname_column(self):
attname = self.get_attname()
column = self.db_column or attname
return attname, column
def get_internal_type(self):
return self.__class__.__name__
def pre_save(self, model_instance, add):
"""Return field's value just before saving."""
return getattr(model_instance, self.attname)
def get_prep_value(self, value):
"""Perform preliminary non-db specific value checks and conversions."""
if isinstance(value, Promise):
value = value._proxy____cast()
return value
def get_db_prep_value(self, value, connection, prepared=False):
"""
Return field's value prepared for interacting with the database backend.
Used by the default implementations of get_db_prep_save().
"""
if not prepared:
value = self.get_prep_value(value)
return value
def get_db_prep_save(self, value, connection):
"""Return field's value prepared for saving into a database."""
if hasattr(value, "as_sql"):
return value
return self.get_db_prep_value(value, connection=connection, prepared=False)
def has_default(self):
"""Return a boolean of whether this field has a default value."""
return self.default is not NOT_PROVIDED
def get_default(self):
"""Return the default value for this field."""
return self._get_default()
@cached_property
def _get_default(self):
if self.has_default():
if callable(self.default):
return self.default
return lambda: self.default
if (
not self.empty_strings_allowed
or self.null
and not connection.features.interprets_empty_strings_as_nulls
):
return return_None
return str # return empty string
def get_choices(
self,
include_blank=True,
blank_choice=BLANK_CHOICE_DASH,
limit_choices_to=None,
ordering=(),
):
"""
Return choices with a default blank choices included, for use
as <select> choices for this field.
"""
if self.choices is not None:
choices = list(self.choices)
if include_blank:
blank_defined = any(
choice in ("", None) for choice, _ in self.flatchoices
)
if not blank_defined:
choices = blank_choice + choices
return choices
rel_model = self.remote_field.model
limit_choices_to = limit_choices_to or self.get_limit_choices_to()
choice_func = operator.attrgetter(
self.remote_field.get_related_field().attname
if hasattr(self.remote_field, "get_related_field")
else "pk"
)
qs = rel_model._default_manager.complex_filter(limit_choices_to)
if ordering:
qs = qs.order_by(*ordering)
return (blank_choice if include_blank else []) + [
(choice_func(x), str(x)) for x in qs
]
def value_to_string(self, obj):
"""
Return a string value of this field from the passed obj.
This is used by the serialization framework.
"""
return str(self.value_from_object(obj))
def _get_flatchoices(self):
"""Flattened version of choices tuple."""
if self.choices is None:
return []
flat = []
for choice, value in self.choices:
if isinstance(value, (list, tuple)):
flat.extend(value)
else:
flat.append((choice, value))
return flat
flatchoices = property(_get_flatchoices)
def save_form_data(self, instance, data):
setattr(instance, self.name, data)
def formfield(self, form_class=None, choices_form_class=None, **kwargs):
"""Return a django.forms.Field instance for this field."""
defaults = {
"required": not self.blank,
"label": capfirst(self.verbose_name),
"help_text": self.help_text,
}
if self.has_default():
if callable(self.default):
defaults["initial"] = self.default
defaults["show_hidden_initial"] = True
else:
defaults["initial"] = self.get_default()
if self.choices is not None:
# Fields with choices get special treatment.
include_blank = self.blank or not (
self.has_default() or "initial" in kwargs
)
defaults["choices"] = self.get_choices(include_blank=include_blank)
defaults["coerce"] = self.to_python
if self.null:
defaults["empty_value"] = None
if choices_form_class is not None:
form_class = choices_form_class
else:
form_class = forms.TypedChoiceField
# Many of the subclass-specific formfield arguments (min_value,
# max_value) don't apply for choice fields, so be sure to only pass
# the values that TypedChoiceField will understand.
for k in list(kwargs):
if k not in (
"coerce",
"empty_value",
"choices",
"required",
"widget",
"label",
"initial",
"help_text",
"error_messages",
"show_hidden_initial",
"disabled",
):
del kwargs[k]
defaults.update(kwargs)
if form_class is None:
form_class = forms.CharField
return form_class(**defaults)
def value_from_object(self, obj):
"""Return the value of this field in the given model instance."""
return getattr(obj, self.attname)
class BooleanField(Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _("“%(value)s” value must be either True or False."),
"invalid_nullable": _("“%(value)s” value must be either True, False, or None."),
}
description = _("Boolean (Either True or False)")
def get_internal_type(self):
return "BooleanField"
def to_python(self, value):
if self.null and value in self.empty_values:
return None
if value in (True, False):
# 1/0 are equal to True/False. bool() converts former to latter.
return bool(value)
if value in ("t", "True", "1"):
return True
if value in ("f", "False", "0"):
return False
raise exceptions.ValidationError(
self.error_messages["invalid_nullable" if self.null else "invalid"],
code="invalid",
params={"value": value},
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return self.to_python(value)
def formfield(self, **kwargs):
if self.choices is not None:
include_blank = not (self.has_default() or "initial" in kwargs)
defaults = {"choices": self.get_choices(include_blank=include_blank)}
else:
form_class = forms.NullBooleanField if self.null else forms.BooleanField
# In HTML checkboxes, 'required' means "must be checked" which is
# different from the choices case ("must select some value").
# required=False allows unchecked checkboxes.
defaults = {"form_class": form_class, "required": False}
return super().formfield(**{**defaults, **kwargs})
class CharField(Field):
def __init__(self, *args, db_collation=None, **kwargs):
super().__init__(*args, **kwargs)
self.db_collation = db_collation
if self.max_length is not None:
self.validators.append(validators.MaxLengthValidator(self.max_length))
@property
def description(self):
if self.max_length is not None:
return _("String (up to %(max_length)s)")
else:
return _("String (unlimited)")
def check(self, **kwargs):
databases = kwargs.get("databases") or []
return [
*super().check(**kwargs),
*self._check_db_collation(databases),
*self._check_max_length_attribute(**kwargs),
]
def _check_max_length_attribute(self, **kwargs):
if self.max_length is None:
if (
connection.features.supports_unlimited_charfield
or "supports_unlimited_charfield"
in self.model._meta.required_db_features
):
return []
return [
checks.Error(
"CharFields must define a 'max_length' attribute.",
obj=self,
id="fields.E120",
)
]
elif (
not isinstance(self.max_length, int)
or isinstance(self.max_length, bool)
or self.max_length <= 0
):
return [
checks.Error(
"'max_length' must be a positive integer.",
obj=self,
id="fields.E121",
)
]
else:
return []
def _check_db_collation(self, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not (
self.db_collation is None
or "supports_collation_on_charfield"
in self.model._meta.required_db_features
or connection.features.supports_collation_on_charfield
):
errors.append(
checks.Error(
"%s does not support a database collation on "
"CharFields." % connection.display_name,
obj=self,
id="fields.E190",
),
)
return errors
def cast_db_type(self, connection):
if self.max_length is None:
return connection.ops.cast_char_field_without_max_length
return super().cast_db_type(connection)
def db_parameters(self, connection):
db_params = super().db_parameters(connection)
db_params["collation"] = self.db_collation
return db_params
def get_internal_type(self):
return "CharField"
def to_python(self, value):
if isinstance(value, str) or value is None:
return value
return str(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
# Passing max_length to forms.CharField means that the value's length
# will be validated twice. This is considered acceptable since we want
# the value in the form field (to pass into widget for example).
defaults = {"max_length": self.max_length}
# TODO: Handle multiple backends with different feature flags.
if self.null and not connection.features.interprets_empty_strings_as_nulls:
defaults["empty_value"] = None
defaults.update(kwargs)
return super().formfield(**defaults)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.db_collation:
kwargs["db_collation"] = self.db_collation
return name, path, args, kwargs
class CommaSeparatedIntegerField(CharField):
default_validators = [validators.validate_comma_separated_integer_list]
description = _("Comma-separated integers")
system_check_removed_details = {
"msg": (
"CommaSeparatedIntegerField is removed except for support in "
"historical migrations."
),
"hint": (
"Use CharField(validators=[validate_comma_separated_integer_list]) "
"instead."
),
"id": "fields.E901",
}
def _to_naive(value):
if timezone.is_aware(value):
value = timezone.make_naive(value, datetime.timezone.utc)
return value
def _get_naive_now():
return _to_naive(timezone.now())
class DateTimeCheckMixin:
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_mutually_exclusive_options(),
*self._check_fix_default_value(),
]
def _check_mutually_exclusive_options(self):
# auto_now, auto_now_add, and default are mutually exclusive
# options. The use of more than one of these options together
# will trigger an Error
mutually_exclusive_options = [
self.auto_now_add,
self.auto_now,
self.has_default(),
]
enabled_options = [
option not in (None, False) for option in mutually_exclusive_options
].count(True)
if enabled_options > 1:
return [
checks.Error(
"The options auto_now, auto_now_add, and default "
"are mutually exclusive. Only one of these options "
"may be present.",
obj=self,
id="fields.E160",
)
]
else:
return []
def _check_fix_default_value(self):
return []
# Concrete subclasses use this in their implementations of
# _check_fix_default_value().
def _check_if_value_fixed(self, value, now=None):
"""
Check if the given value appears to have been provided as a "fixed"
time value, and include a warning in the returned list if it does. The
value argument must be a date object or aware/naive datetime object. If
now is provided, it must be a naive datetime object.
"""
if now is None:
now = _get_naive_now()
offset = datetime.timedelta(seconds=10)
lower = now - offset
upper = now + offset
if isinstance(value, datetime.datetime):
value = _to_naive(value)
else:
assert isinstance(value, datetime.date)
lower = lower.date()
upper = upper.date()
if lower <= value <= upper:
return [
checks.Warning(
"Fixed default value provided.",
hint=(
"It seems you set a fixed date / time / datetime "
"value as default for this field. This may not be "
"what you want. If you want to have the current date "
"as default, use `django.utils.timezone.now`"
),
obj=self,
id="fields.W161",
)
]
return []
class DateField(DateTimeCheckMixin, Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _(
"“%(value)s” value has an invalid date format. It must be "
"in YYYY-MM-DD format."
),
"invalid_date": _(
"“%(value)s” value has the correct format (YYYY-MM-DD) "
"but it is an invalid date."
),
}
description = _("Date (without time)")
def __init__(
self, verbose_name=None, name=None, auto_now=False, auto_now_add=False, **kwargs
):
self.auto_now, self.auto_now_add = auto_now, auto_now_add
if auto_now or auto_now_add:
kwargs["editable"] = False
kwargs["blank"] = True
super().__init__(verbose_name, name, **kwargs)
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, datetime.datetime):
value = _to_naive(value).date()
elif isinstance(value, datetime.date):
pass
else:
# No explicit date / datetime value -- no checks necessary
return []
# At this point, value is a date object.
return self._check_if_value_fixed(value)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.auto_now:
kwargs["auto_now"] = True
if self.auto_now_add:
kwargs["auto_now_add"] = True
if self.auto_now or self.auto_now_add:
del kwargs["editable"]
del kwargs["blank"]
return name, path, args, kwargs
def get_internal_type(self):
return "DateField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.datetime):
if settings.USE_TZ and timezone.is_aware(value):
# Convert aware datetimes to the default time zone
# before casting them to dates (#17742).
default_timezone = timezone.get_default_timezone()
value = timezone.make_naive(value, default_timezone)
return value.date()
if isinstance(value, datetime.date):
return value
try:
parsed = parse_date(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages["invalid_date"],
code="invalid_date",
params={"value": value},
)
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = datetime.date.today()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
if not self.null:
setattr(
cls,
"get_next_by_%s" % self.name,
partialmethod(
cls._get_next_or_previous_by_FIELD, field=self, is_next=True
),
)
setattr(
cls,
"get_previous_by_%s" % self.name,
partialmethod(
cls._get_next_or_previous_by_FIELD, field=self, is_next=False
),
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
# Casts dates into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_datefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return "" if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.DateField,
**kwargs,
}
)
class DateTimeField(DateField):
empty_strings_allowed = False
default_error_messages = {
"invalid": _(
"“%(value)s” value has an invalid format. It must be in "
"YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."
),
"invalid_date": _(
"“%(value)s” value has the correct format "
"(YYYY-MM-DD) but it is an invalid date."
),
"invalid_datetime": _(
"“%(value)s” value has the correct format "
"(YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]) "
"but it is an invalid date/time."
),
}
description = _("Date (with time)")
# __init__ is inherited from DateField
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, (datetime.datetime, datetime.date)):
return self._check_if_value_fixed(value)
# No explicit date / datetime value -- no checks necessary.
return []
def get_internal_type(self):
return "DateTimeField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.datetime):
return value
if isinstance(value, datetime.date):
value = datetime.datetime(value.year, value.month, value.day)
if settings.USE_TZ:
# For backwards compatibility, interpret naive datetimes in
# local time. This won't work during DST change, but we can't
# do much about it, so we let the exceptions percolate up the
# call stack.
warnings.warn(
"DateTimeField %s.%s received a naive datetime "
"(%s) while time zone support is active."
% (self.model.__name__, self.name, value),
RuntimeWarning,
)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
try:
parsed = parse_datetime(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages["invalid_datetime"],
code="invalid_datetime",
params={"value": value},
)
try:
parsed = parse_date(value)
if parsed is not None:
return datetime.datetime(parsed.year, parsed.month, parsed.day)
except ValueError:
raise exceptions.ValidationError(
self.error_messages["invalid_date"],
code="invalid_date",
params={"value": value},
)
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = timezone.now()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
# contribute_to_class is inherited from DateField, it registers
# get_next_by_FOO and get_prev_by_FOO
def get_prep_value(self, value):
value = super().get_prep_value(value)
value = self.to_python(value)
if value is not None and settings.USE_TZ and timezone.is_naive(value):
# For backwards compatibility, interpret naive datetimes in local
# time. This won't work during DST change, but we can't do much
# about it, so we let the exceptions percolate up the call stack.
try:
name = "%s.%s" % (self.model.__name__, self.name)
except AttributeError:
name = "(unbound)"
warnings.warn(
"DateTimeField %s received a naive datetime (%s)"
" while time zone support is active." % (name, value),
RuntimeWarning,
)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
def get_db_prep_value(self, value, connection, prepared=False):
# Casts datetimes into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_datetimefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return "" if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.DateTimeField,
**kwargs,
}
)
class DecimalField(Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _("“%(value)s” value must be a decimal number."),
}
description = _("Decimal number")
def __init__(
self,
verbose_name=None,
name=None,
max_digits=None,
decimal_places=None,
**kwargs,
):
self.max_digits, self.decimal_places = max_digits, decimal_places
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
errors = super().check(**kwargs)
digits_errors = [
*self._check_decimal_places(),
*self._check_max_digits(),
]
if not digits_errors:
errors.extend(self._check_decimal_places_and_max_digits(**kwargs))
else:
errors.extend(digits_errors)
return errors
def _check_decimal_places(self):
try:
decimal_places = int(self.decimal_places)
if decimal_places < 0:
raise ValueError()
except TypeError:
return [
checks.Error(
"DecimalFields must define a 'decimal_places' attribute.",
obj=self,
id="fields.E130",
)
]
except ValueError:
return [
checks.Error(
"'decimal_places' must be a non-negative integer.",
obj=self,
id="fields.E131",
)
]
else:
return []
def _check_max_digits(self):
try:
max_digits = int(self.max_digits)
if max_digits <= 0:
raise ValueError()
except TypeError:
return [
checks.Error(
"DecimalFields must define a 'max_digits' attribute.",
obj=self,
id="fields.E132",
)
]
except ValueError:
return [
checks.Error(
"'max_digits' must be a positive integer.",
obj=self,
id="fields.E133",
)
]
else:
return []
def _check_decimal_places_and_max_digits(self, **kwargs):
if int(self.decimal_places) > int(self.max_digits):
return [
checks.Error(
"'max_digits' must be greater or equal to 'decimal_places'.",
obj=self,
id="fields.E134",
)
]
return []
@cached_property
def validators(self):
return super().validators + [
validators.DecimalValidator(self.max_digits, self.decimal_places)
]
@cached_property
def context(self):
return decimal.Context(prec=self.max_digits)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.max_digits is not None:
kwargs["max_digits"] = self.max_digits
if self.decimal_places is not None:
kwargs["decimal_places"] = self.decimal_places
return name, path, args, kwargs
def get_internal_type(self):
return "DecimalField"
def to_python(self, value):
if value is None:
return value
try:
if isinstance(value, float):
decimal_value = self.context.create_decimal_from_float(value)
else:
decimal_value = decimal.Decimal(value)
except (decimal.InvalidOperation, TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
if not decimal_value.is_finite():
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
return decimal_value
def get_db_prep_save(self, value, connection):
if hasattr(value, "as_sql"):
return value
return connection.ops.adapt_decimalfield_value(
self.to_python(value), self.max_digits, self.decimal_places
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
return super().formfield(
**{
"max_digits": self.max_digits,
"decimal_places": self.decimal_places,
"form_class": forms.DecimalField,
**kwargs,
}
)
class DurationField(Field):
"""
Store timedelta objects.
Use interval on PostgreSQL, INTERVAL DAY TO SECOND on Oracle, and bigint
of microseconds on other databases.
"""
empty_strings_allowed = False
default_error_messages = {
"invalid": _(
"“%(value)s” value has an invalid format. It must be in "
"[DD] [[HH:]MM:]ss[.uuuuuu] format."
)
}
description = _("Duration")
def get_internal_type(self):
return "DurationField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.timedelta):
return value
try:
parsed = parse_duration(value)
except ValueError:
pass
else:
if parsed is not None:
return parsed
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def get_db_prep_value(self, value, connection, prepared=False):
if connection.features.has_native_duration_field:
return value
if value is None:
return None
return duration_microseconds(value)
def get_db_converters(self, connection):
converters = []
if not connection.features.has_native_duration_field:
converters.append(connection.ops.convert_durationfield_value)
return converters + super().get_db_converters(connection)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return "" if val is None else duration_string(val)
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.DurationField,
**kwargs,
}
)
class EmailField(CharField):
default_validators = [validators.validate_email]
description = _("Email address")
def __init__(self, *args, **kwargs):
# max_length=254 to be compliant with RFCs 3696 and 5321
kwargs.setdefault("max_length", 254)
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
# We do not exclude max_length if it matches default as we want to change
# the default in future.
return name, path, args, kwargs
def formfield(self, **kwargs):
# As with CharField, this will cause email validation to be performed
# twice.
return super().formfield(
**{
"form_class": forms.EmailField,
**kwargs,
}
)
class FilePathField(Field):
description = _("File path")
def __init__(
self,
verbose_name=None,
name=None,
path="",
match=None,
recursive=False,
allow_files=True,
allow_folders=False,
**kwargs,
):
self.path, self.match, self.recursive = path, match, recursive
self.allow_files, self.allow_folders = allow_files, allow_folders
kwargs.setdefault("max_length", 100)
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_allowing_files_or_folders(**kwargs),
]
def _check_allowing_files_or_folders(self, **kwargs):
if not self.allow_files and not self.allow_folders:
return [
checks.Error(
"FilePathFields must have either 'allow_files' or 'allow_folders' "
"set to True.",
obj=self,
id="fields.E140",
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.path != "":
kwargs["path"] = self.path
if self.match is not None:
kwargs["match"] = self.match
if self.recursive is not False:
kwargs["recursive"] = self.recursive
if self.allow_files is not True:
kwargs["allow_files"] = self.allow_files
if self.allow_folders is not False:
kwargs["allow_folders"] = self.allow_folders
if kwargs.get("max_length") == 100:
del kwargs["max_length"]
return name, path, args, kwargs
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return str(value)
def formfield(self, **kwargs):
return super().formfield(
**{
"path": self.path() if callable(self.path) else self.path,
"match": self.match,
"recursive": self.recursive,
"form_class": forms.FilePathField,
"allow_files": self.allow_files,
"allow_folders": self.allow_folders,
**kwargs,
}
)
def get_internal_type(self):
return "FilePathField"
class FloatField(Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _("“%(value)s” value must be a float."),
}
description = _("Floating point number")
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
try:
return float(value)
except (TypeError, ValueError) as e:
raise e.__class__(
"Field '%s' expected a number but got %r." % (self.name, value),
) from e
def get_internal_type(self):
return "FloatField"
def to_python(self, value):
if value is None:
return value
try:
return float(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.FloatField,
**kwargs,
}
)
class IntegerField(Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _("“%(value)s” value must be an integer."),
}
description = _("Integer")
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_max_length_warning(),
]
def _check_max_length_warning(self):
if self.max_length is not None:
return [
checks.Warning(
"'max_length' is ignored when used with %s."
% self.__class__.__name__,
hint="Remove 'max_length' from field",
obj=self,
id="fields.W122",
)
]
return []
@cached_property
def validators(self):
# These validators can't be added at field initialization time since
# they're based on values retrieved from `connection`.
validators_ = super().validators
internal_type = self.get_internal_type()
min_value, max_value = connection.ops.integer_field_range(internal_type)
if min_value is not None and not any(
(
isinstance(validator, validators.MinValueValidator)
and (
validator.limit_value()
if callable(validator.limit_value)
else validator.limit_value
)
>= min_value
)
for validator in validators_
):
validators_.append(validators.MinValueValidator(min_value))
if max_value is not None and not any(
(
isinstance(validator, validators.MaxValueValidator)
and (
validator.limit_value()
if callable(validator.limit_value)
else validator.limit_value
)
<= max_value
)
for validator in validators_
):
validators_.append(validators.MaxValueValidator(max_value))
return validators_
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
try:
return int(value)
except (TypeError, ValueError) as e:
raise e.__class__(
"Field '%s' expected a number but got %r." % (self.name, value),
) from e
def get_db_prep_value(self, value, connection, prepared=False):
value = super().get_db_prep_value(value, connection, prepared)
return connection.ops.adapt_integerfield_value(value, self.get_internal_type())
def get_internal_type(self):
return "IntegerField"
def to_python(self, value):
if value is None:
return value
try:
return int(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.IntegerField,
**kwargs,
}
)
class BigIntegerField(IntegerField):
description = _("Big (8 byte) integer")
MAX_BIGINT = 9223372036854775807
def get_internal_type(self):
return "BigIntegerField"
def formfield(self, **kwargs):
return super().formfield(
**{
"min_value": -BigIntegerField.MAX_BIGINT - 1,
"max_value": BigIntegerField.MAX_BIGINT,
**kwargs,
}
)
class SmallIntegerField(IntegerField):
description = _("Small integer")
def get_internal_type(self):
return "SmallIntegerField"
class IPAddressField(Field):
empty_strings_allowed = False
description = _("IPv4 address")
system_check_removed_details = {
"msg": (
"IPAddressField has been removed except for support in "
"historical migrations."
),
"hint": "Use GenericIPAddressField instead.",
"id": "fields.E900",
}
def __init__(self, *args, **kwargs):
kwargs["max_length"] = 15
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["max_length"]
return name, path, args, kwargs
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return str(value)
def get_internal_type(self):
return "IPAddressField"
class GenericIPAddressField(Field):
empty_strings_allowed = False
description = _("IP address")
default_error_messages = {}
def __init__(
self,
verbose_name=None,
name=None,
protocol="both",
unpack_ipv4=False,
*args,
**kwargs,
):
self.unpack_ipv4 = unpack_ipv4
self.protocol = protocol
(
self.default_validators,
invalid_error_message,
) = validators.ip_address_validators(protocol, unpack_ipv4)
self.default_error_messages["invalid"] = invalid_error_message
kwargs["max_length"] = 39
super().__init__(verbose_name, name, *args, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_blank_and_null_values(**kwargs),
]
def _check_blank_and_null_values(self, **kwargs):
if not getattr(self, "null", False) and getattr(self, "blank", False):
return [
checks.Error(
"GenericIPAddressFields cannot have blank=True if null=False, "
"as blank values are stored as nulls.",
obj=self,
id="fields.E150",
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.unpack_ipv4 is not False:
kwargs["unpack_ipv4"] = self.unpack_ipv4
if self.protocol != "both":
kwargs["protocol"] = self.protocol
if kwargs.get("max_length") == 39:
del kwargs["max_length"]
return name, path, args, kwargs
def get_internal_type(self):
return "GenericIPAddressField"
def to_python(self, value):
if value is None:
return None
if not isinstance(value, str):
value = str(value)
value = value.strip()
if ":" in value:
return clean_ipv6_address(
value, self.unpack_ipv4, self.error_messages["invalid"]
)
return value
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_ipaddressfield_value(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
if value and ":" in value:
try:
return clean_ipv6_address(value, self.unpack_ipv4)
except exceptions.ValidationError:
pass
return str(value)
def formfield(self, **kwargs):
return super().formfield(
**{
"protocol": self.protocol,
"form_class": forms.GenericIPAddressField,
**kwargs,
}
)
class NullBooleanField(BooleanField):
default_error_messages = {
"invalid": _("“%(value)s” value must be either None, True or False."),
"invalid_nullable": _("“%(value)s” value must be either None, True or False."),
}
description = _("Boolean (Either True, False or None)")
system_check_removed_details = {
"msg": (
"NullBooleanField is removed except for support in historical "
"migrations."
),
"hint": "Use BooleanField(null=True) instead.",
"id": "fields.E903",
}
def __init__(self, *args, **kwargs):
kwargs["null"] = True
kwargs["blank"] = True
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["null"]
del kwargs["blank"]
return name, path, args, kwargs
class PositiveIntegerRelDbTypeMixin:
def __init_subclass__(cls, **kwargs):
super().__init_subclass__(**kwargs)
if not hasattr(cls, "integer_field_class"):
cls.integer_field_class = next(
(
parent
for parent in cls.__mro__[1:]
if issubclass(parent, IntegerField)
),
None,
)
def rel_db_type(self, connection):
"""
Return the data type that a related field pointing to this field should
use. In most cases, a foreign key pointing to a positive integer
primary key will have an integer column data type but some databases
(e.g. MySQL) have an unsigned integer type. In that case
(related_fields_match_type=True), the primary key should return its
db_type.
"""
if connection.features.related_fields_match_type:
return self.db_type(connection)
else:
return self.integer_field_class().db_type(connection=connection)
class PositiveBigIntegerField(PositiveIntegerRelDbTypeMixin, BigIntegerField):
description = _("Positive big integer")
def get_internal_type(self):
return "PositiveBigIntegerField"
def formfield(self, **kwargs):
return super().formfield(
**{
"min_value": 0,
**kwargs,
}
)
class PositiveIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField):
description = _("Positive integer")
def get_internal_type(self):
return "PositiveIntegerField"
def formfield(self, **kwargs):
return super().formfield(
**{
"min_value": 0,
**kwargs,
}
)
class PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin, SmallIntegerField):
description = _("Positive small integer")
def get_internal_type(self):
return "PositiveSmallIntegerField"
def formfield(self, **kwargs):
return super().formfield(
**{
"min_value": 0,
**kwargs,
}
)
class SlugField(CharField):
default_validators = [validators.validate_slug]
description = _("Slug (up to %(max_length)s)")
def __init__(
self, *args, max_length=50, db_index=True, allow_unicode=False, **kwargs
):
self.allow_unicode = allow_unicode
if self.allow_unicode:
self.default_validators = [validators.validate_unicode_slug]
super().__init__(*args, max_length=max_length, db_index=db_index, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 50:
del kwargs["max_length"]
if self.db_index is False:
kwargs["db_index"] = False
else:
del kwargs["db_index"]
if self.allow_unicode is not False:
kwargs["allow_unicode"] = self.allow_unicode
return name, path, args, kwargs
def get_internal_type(self):
return "SlugField"
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.SlugField,
"allow_unicode": self.allow_unicode,
**kwargs,
}
)
class TextField(Field):
description = _("Text")
def __init__(self, *args, db_collation=None, **kwargs):
super().__init__(*args, **kwargs)
self.db_collation = db_collation
def check(self, **kwargs):
databases = kwargs.get("databases") or []
return [
*super().check(**kwargs),
*self._check_db_collation(databases),
]
def _check_db_collation(self, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not (
self.db_collation is None
or "supports_collation_on_textfield"
in self.model._meta.required_db_features
or connection.features.supports_collation_on_textfield
):
errors.append(
checks.Error(
"%s does not support a database collation on "
"TextFields." % connection.display_name,
obj=self,
id="fields.E190",
),
)
return errors
def db_parameters(self, connection):
db_params = super().db_parameters(connection)
db_params["collation"] = self.db_collation
return db_params
def get_internal_type(self):
return "TextField"
def to_python(self, value):
if isinstance(value, str) or value is None:
return value
return str(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
# Passing max_length to forms.CharField means that the value's length
# will be validated twice. This is considered acceptable since we want
# the value in the form field (to pass into widget for example).
return super().formfield(
**{
"max_length": self.max_length,
**({} if self.choices is not None else {"widget": forms.Textarea}),
**kwargs,
}
)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.db_collation:
kwargs["db_collation"] = self.db_collation
return name, path, args, kwargs
class TimeField(DateTimeCheckMixin, Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _(
"“%(value)s” value has an invalid format. It must be in "
"HH:MM[:ss[.uuuuuu]] format."
),
"invalid_time": _(
"“%(value)s” value has the correct format "
"(HH:MM[:ss[.uuuuuu]]) but it is an invalid time."
),
}
description = _("Time")
def __init__(
self, verbose_name=None, name=None, auto_now=False, auto_now_add=False, **kwargs
):
self.auto_now, self.auto_now_add = auto_now, auto_now_add
if auto_now or auto_now_add:
kwargs["editable"] = False
kwargs["blank"] = True
super().__init__(verbose_name, name, **kwargs)
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, datetime.datetime):
now = None
elif isinstance(value, datetime.time):
now = _get_naive_now()
# This will not use the right date in the race condition where now
# is just before the date change and value is just past 0:00.
value = datetime.datetime.combine(now.date(), value)
else:
# No explicit time / datetime value -- no checks necessary
return []
# At this point, value is a datetime object.
return self._check_if_value_fixed(value, now=now)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.auto_now is not False:
kwargs["auto_now"] = self.auto_now
if self.auto_now_add is not False:
kwargs["auto_now_add"] = self.auto_now_add
if self.auto_now or self.auto_now_add:
del kwargs["blank"]
del kwargs["editable"]
return name, path, args, kwargs
def get_internal_type(self):
return "TimeField"
def to_python(self, value):
if value is None:
return None
if isinstance(value, datetime.time):
return value
if isinstance(value, datetime.datetime):
# Not usually a good idea to pass in a datetime here (it loses
# information), but this can be a side-effect of interacting with a
# database backend (e.g. Oracle), so we'll be accommodating.
return value.time()
try:
parsed = parse_time(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages["invalid_time"],
code="invalid_time",
params={"value": value},
)
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = datetime.datetime.now().time()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
# Casts times into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_timefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return "" if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.TimeField,
**kwargs,
}
)
class URLField(CharField):
default_validators = [validators.URLValidator()]
description = _("URL")
def __init__(self, verbose_name=None, name=None, **kwargs):
kwargs.setdefault("max_length", 200)
super().__init__(verbose_name, name, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 200:
del kwargs["max_length"]
return name, path, args, kwargs
def formfield(self, **kwargs):
# As with CharField, this will cause URL validation to be performed
# twice.
return super().formfield(
**{
"form_class": forms.URLField,
**kwargs,
}
)
class BinaryField(Field):
description = _("Raw binary data")
empty_values = [None, b""]
def __init__(self, *args, **kwargs):
kwargs.setdefault("editable", False)
super().__init__(*args, **kwargs)
if self.max_length is not None:
self.validators.append(validators.MaxLengthValidator(self.max_length))
def check(self, **kwargs):
return [*super().check(**kwargs), *self._check_str_default_value()]
def _check_str_default_value(self):
if self.has_default() and isinstance(self.default, str):
return [
checks.Error(
"BinaryField's default cannot be a string. Use bytes "
"content instead.",
obj=self,
id="fields.E170",
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.editable:
kwargs["editable"] = True
else:
del kwargs["editable"]
return name, path, args, kwargs
def get_internal_type(self):
return "BinaryField"
def get_placeholder(self, value, compiler, connection):
return connection.ops.binary_placeholder_sql(value)
def get_default(self):
if self.has_default() and not callable(self.default):
return self.default
default = super().get_default()
if default == "":
return b""
return default
def get_db_prep_value(self, value, connection, prepared=False):
value = super().get_db_prep_value(value, connection, prepared)
if value is not None:
return connection.Database.Binary(value)
return value
def value_to_string(self, obj):
"""Binary data is serialized as base64"""
return b64encode(self.value_from_object(obj)).decode("ascii")
def to_python(self, value):
# If it's a string, it should be base64-encoded data
if isinstance(value, str):
return memoryview(b64decode(value.encode("ascii")))
return value
class UUIDField(Field):
default_error_messages = {
"invalid": _("“%(value)s” is not a valid UUID."),
}
description = _("Universally unique identifier")
empty_strings_allowed = False
def __init__(self, verbose_name=None, **kwargs):
kwargs["max_length"] = 32
super().__init__(verbose_name, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["max_length"]
return name, path, args, kwargs
def get_internal_type(self):
return "UUIDField"
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
if value is None:
return None
if not isinstance(value, uuid.UUID):
value = self.to_python(value)
if connection.features.has_native_uuid_field:
return value
return value.hex
def to_python(self, value):
if value is not None and not isinstance(value, uuid.UUID):
input_form = "int" if isinstance(value, int) else "hex"
try:
return uuid.UUID(**{input_form: value})
except (AttributeError, ValueError):
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
return value
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.UUIDField,
**kwargs,
}
)
class AutoFieldMixin:
db_returning = True
def __init__(self, *args, **kwargs):
kwargs["blank"] = True
super().__init__(*args, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_primary_key(),
]
def _check_primary_key(self):
if not self.primary_key:
return [
checks.Error(
"AutoFields must set primary_key=True.",
obj=self,
id="fields.E100",
),
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["blank"]
kwargs["primary_key"] = True
return name, path, args, kwargs
def validate(self, value, model_instance):
pass
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
value = connection.ops.validate_autopk_value(value)
return value
def contribute_to_class(self, cls, name, **kwargs):
if cls._meta.auto_field:
raise ValueError(
"Model %s can't have more than one auto-generated field."
% cls._meta.label
)
super().contribute_to_class(cls, name, **kwargs)
cls._meta.auto_field = self
def formfield(self, **kwargs):
return None
class AutoFieldMeta(type):
"""
Metaclass to maintain backward inheritance compatibility for AutoField.
It is intended that AutoFieldMixin become public API when it is possible to
create a non-integer automatically-generated field using column defaults
stored in the database.
In many areas Django also relies on using isinstance() to check for an
automatically-generated field as a subclass of AutoField. A new flag needs
to be implemented on Field to be used instead.
When these issues have been addressed, this metaclass could be used to
deprecate inheritance from AutoField and use of isinstance() with AutoField
for detecting automatically-generated fields.
"""
@property
def _subclasses(self):
return (BigAutoField, SmallAutoField)
def __instancecheck__(self, instance):
return isinstance(instance, self._subclasses) or super().__instancecheck__(
instance
)
def __subclasscheck__(self, subclass):
return issubclass(subclass, self._subclasses) or super().__subclasscheck__(
subclass
)
class AutoField(AutoFieldMixin, IntegerField, metaclass=AutoFieldMeta):
def get_internal_type(self):
return "AutoField"
def rel_db_type(self, connection):
return IntegerField().db_type(connection=connection)
class BigAutoField(AutoFieldMixin, BigIntegerField):
def get_internal_type(self):
return "BigAutoField"
def rel_db_type(self, connection):
return BigIntegerField().db_type(connection=connection)
class SmallAutoField(AutoFieldMixin, SmallIntegerField):
def get_internal_type(self):
return "SmallAutoField"
def rel_db_type(self, connection):
return SmallIntegerField().db_type(connection=connection)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/__init__.py
|
Python
|
mit
| 95,674 |
import datetime
import posixpath
from django import forms
from django.core import checks
from django.core.files.base import File
from django.core.files.images import ImageFile
from django.core.files.storage import Storage, default_storage
from django.core.files.utils import validate_file_name
from django.db.models import signals
from django.db.models.fields import Field
from django.db.models.query_utils import DeferredAttribute
from django.db.models.utils import AltersData
from django.utils.translation import gettext_lazy as _
class FieldFile(File, AltersData):
def __init__(self, instance, field, name):
super().__init__(None, name)
self.instance = instance
self.field = field
self.storage = field.storage
self._committed = True
def __eq__(self, other):
# Older code may be expecting FileField values to be simple strings.
# By overriding the == operator, it can remain backwards compatibility.
if hasattr(other, "name"):
return self.name == other.name
return self.name == other
def __hash__(self):
return hash(self.name)
# The standard File contains most of the necessary properties, but
# FieldFiles can be instantiated without a name, so that needs to
# be checked for here.
def _require_file(self):
if not self:
raise ValueError(
"The '%s' attribute has no file associated with it." % self.field.name
)
def _get_file(self):
self._require_file()
if getattr(self, "_file", None) is None:
self._file = self.storage.open(self.name, "rb")
return self._file
def _set_file(self, file):
self._file = file
def _del_file(self):
del self._file
file = property(_get_file, _set_file, _del_file)
@property
def path(self):
self._require_file()
return self.storage.path(self.name)
@property
def url(self):
self._require_file()
return self.storage.url(self.name)
@property
def size(self):
self._require_file()
if not self._committed:
return self.file.size
return self.storage.size(self.name)
def open(self, mode="rb"):
self._require_file()
if getattr(self, "_file", None) is None:
self.file = self.storage.open(self.name, mode)
else:
self.file.open(mode)
return self
# open() doesn't alter the file's contents, but it does reset the pointer
open.alters_data = True
# In addition to the standard File API, FieldFiles have extra methods
# to further manipulate the underlying file, as well as update the
# associated model instance.
def save(self, name, content, save=True):
name = self.field.generate_filename(self.instance, name)
self.name = self.storage.save(name, content, max_length=self.field.max_length)
setattr(self.instance, self.field.attname, self.name)
self._committed = True
# Save the object because it has changed, unless save is False
if save:
self.instance.save()
save.alters_data = True
def delete(self, save=True):
if not self:
return
# Only close the file if it's already open, which we know by the
# presence of self._file
if hasattr(self, "_file"):
self.close()
del self.file
self.storage.delete(self.name)
self.name = None
setattr(self.instance, self.field.attname, self.name)
self._committed = False
if save:
self.instance.save()
delete.alters_data = True
@property
def closed(self):
file = getattr(self, "_file", None)
return file is None or file.closed
def close(self):
file = getattr(self, "_file", None)
if file is not None:
file.close()
def __getstate__(self):
# FieldFile needs access to its associated model field, an instance and
# the file's name. Everything else will be restored later, by
# FileDescriptor below.
return {
"name": self.name,
"closed": False,
"_committed": True,
"_file": None,
"instance": self.instance,
"field": self.field,
}
def __setstate__(self, state):
self.__dict__.update(state)
self.storage = self.field.storage
class FileDescriptor(DeferredAttribute):
"""
The descriptor for the file attribute on the model instance. Return a
FieldFile when accessed so you can write code like::
>>> from myapp.models import MyModel
>>> instance = MyModel.objects.get(pk=1)
>>> instance.file.size
Assign a file object on assignment so you can do::
>>> with open('/path/to/hello.world') as f:
... instance.file = File(f)
"""
def __get__(self, instance, cls=None):
if instance is None:
return self
# This is slightly complicated, so worth an explanation.
# instance.file needs to ultimately return some instance of `File`,
# probably a subclass. Additionally, this returned object needs to have
# the FieldFile API so that users can easily do things like
# instance.file.path and have that delegated to the file storage engine.
# Easy enough if we're strict about assignment in __set__, but if you
# peek below you can see that we're not. So depending on the current
# value of the field we have to dynamically construct some sort of
# "thing" to return.
# The instance dict contains whatever was originally assigned
# in __set__.
file = super().__get__(instance, cls)
# If this value is a string (instance.file = "path/to/file") or None
# then we simply wrap it with the appropriate attribute class according
# to the file field. [This is FieldFile for FileFields and
# ImageFieldFile for ImageFields; it's also conceivable that user
# subclasses might also want to subclass the attribute class]. This
# object understands how to convert a path to a file, and also how to
# handle None.
if isinstance(file, str) or file is None:
attr = self.field.attr_class(instance, self.field, file)
instance.__dict__[self.field.attname] = attr
# Other types of files may be assigned as well, but they need to have
# the FieldFile interface added to them. Thus, we wrap any other type of
# File inside a FieldFile (well, the field's attr_class, which is
# usually FieldFile).
elif isinstance(file, File) and not isinstance(file, FieldFile):
file_copy = self.field.attr_class(instance, self.field, file.name)
file_copy.file = file
file_copy._committed = False
instance.__dict__[self.field.attname] = file_copy
# Finally, because of the (some would say boneheaded) way pickle works,
# the underlying FieldFile might not actually itself have an associated
# file. So we need to reset the details of the FieldFile in those cases.
elif isinstance(file, FieldFile) and not hasattr(file, "field"):
file.instance = instance
file.field = self.field
file.storage = self.field.storage
# Make sure that the instance is correct.
elif isinstance(file, FieldFile) and instance is not file.instance:
file.instance = instance
# That was fun, wasn't it?
return instance.__dict__[self.field.attname]
def __set__(self, instance, value):
instance.__dict__[self.field.attname] = value
class FileField(Field):
# The class to wrap instance attributes in. Accessing the file object off
# the instance will always return an instance of attr_class.
attr_class = FieldFile
# The descriptor to use for accessing the attribute off of the class.
descriptor_class = FileDescriptor
description = _("File")
def __init__(
self, verbose_name=None, name=None, upload_to="", storage=None, **kwargs
):
self._primary_key_set_explicitly = "primary_key" in kwargs
self.storage = storage or default_storage
if callable(self.storage):
# Hold a reference to the callable for deconstruct().
self._storage_callable = self.storage
self.storage = self.storage()
if not isinstance(self.storage, Storage):
raise TypeError(
"%s.storage must be a subclass/instance of %s.%s"
% (
self.__class__.__qualname__,
Storage.__module__,
Storage.__qualname__,
)
)
self.upload_to = upload_to
kwargs.setdefault("max_length", 100)
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_primary_key(),
*self._check_upload_to(),
]
def _check_primary_key(self):
if self._primary_key_set_explicitly:
return [
checks.Error(
"'primary_key' is not a valid argument for a %s."
% self.__class__.__name__,
obj=self,
id="fields.E201",
)
]
else:
return []
def _check_upload_to(self):
if isinstance(self.upload_to, str) and self.upload_to.startswith("/"):
return [
checks.Error(
"%s's 'upload_to' argument must be a relative path, not an "
"absolute path." % self.__class__.__name__,
obj=self,
id="fields.E202",
hint="Remove the leading slash.",
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 100:
del kwargs["max_length"]
kwargs["upload_to"] = self.upload_to
storage = getattr(self, "_storage_callable", self.storage)
if storage is not default_storage:
kwargs["storage"] = storage
return name, path, args, kwargs
def get_internal_type(self):
return "FileField"
def get_prep_value(self, value):
value = super().get_prep_value(value)
# Need to convert File objects provided via a form to string for
# database insertion.
if value is None:
return None
return str(value)
def pre_save(self, model_instance, add):
file = super().pre_save(model_instance, add)
if file and not file._committed:
# Commit the file to storage prior to saving the model
file.save(file.name, file.file, save=False)
return file
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
setattr(cls, self.attname, self.descriptor_class(self))
def generate_filename(self, instance, filename):
"""
Apply (if callable) or prepend (if a string) upload_to to the filename,
then delegate further processing of the name to the storage backend.
Until the storage layer, all file paths are expected to be Unix style
(with forward slashes).
"""
if callable(self.upload_to):
filename = self.upload_to(instance, filename)
else:
dirname = datetime.datetime.now().strftime(str(self.upload_to))
filename = posixpath.join(dirname, filename)
filename = validate_file_name(filename, allow_relative_path=True)
return self.storage.generate_filename(filename)
def save_form_data(self, instance, data):
# Important: None means "no change", other false value means "clear"
# This subtle distinction (rather than a more explicit marker) is
# needed because we need to consume values that are also sane for a
# regular (non Model-) Form to find in its cleaned_data dictionary.
if data is not None:
# This value will be converted to str and stored in the
# database, so leaving False as-is is not acceptable.
setattr(instance, self.name, data or "")
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.FileField,
"max_length": self.max_length,
**kwargs,
}
)
class ImageFileDescriptor(FileDescriptor):
"""
Just like the FileDescriptor, but for ImageFields. The only difference is
assigning the width/height to the width_field/height_field, if appropriate.
"""
def __set__(self, instance, value):
previous_file = instance.__dict__.get(self.field.attname)
super().__set__(instance, value)
# To prevent recalculating image dimensions when we are instantiating
# an object from the database (bug #11084), only update dimensions if
# the field had a value before this assignment. Since the default
# value for FileField subclasses is an instance of field.attr_class,
# previous_file will only be None when we are called from
# Model.__init__(). The ImageField.update_dimension_fields method
# hooked up to the post_init signal handles the Model.__init__() cases.
# Assignment happening outside of Model.__init__() will trigger the
# update right here.
if previous_file is not None:
self.field.update_dimension_fields(instance, force=True)
class ImageFieldFile(ImageFile, FieldFile):
def delete(self, save=True):
# Clear the image dimensions cache
if hasattr(self, "_dimensions_cache"):
del self._dimensions_cache
super().delete(save)
class ImageField(FileField):
attr_class = ImageFieldFile
descriptor_class = ImageFileDescriptor
description = _("Image")
def __init__(
self,
verbose_name=None,
name=None,
width_field=None,
height_field=None,
**kwargs,
):
self.width_field, self.height_field = width_field, height_field
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_image_library_installed(),
]
def _check_image_library_installed(self):
try:
from PIL import Image # NOQA
except ImportError:
return [
checks.Error(
"Cannot use ImageField because Pillow is not installed.",
hint=(
"Get Pillow at https://pypi.org/project/Pillow/ "
'or run command "python -m pip install Pillow".'
),
obj=self,
id="fields.E210",
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.width_field:
kwargs["width_field"] = self.width_field
if self.height_field:
kwargs["height_field"] = self.height_field
return name, path, args, kwargs
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
# Attach update_dimension_fields so that dimension fields declared
# after their corresponding image field don't stay cleared by
# Model.__init__, see bug #11196.
# Only run post-initialization dimension update on non-abstract models
if not cls._meta.abstract:
signals.post_init.connect(self.update_dimension_fields, sender=cls)
def update_dimension_fields(self, instance, force=False, *args, **kwargs):
"""
Update field's width and height fields, if defined.
This method is hooked up to model's post_init signal to update
dimensions after instantiating a model instance. However, dimensions
won't be updated if the dimensions fields are already populated. This
avoids unnecessary recalculation when loading an object from the
database.
Dimensions can be forced to update with force=True, which is how
ImageFileDescriptor.__set__ calls this method.
"""
# Nothing to update if the field doesn't have dimension fields or if
# the field is deferred.
has_dimension_fields = self.width_field or self.height_field
if not has_dimension_fields or self.attname not in instance.__dict__:
return
# getattr will call the ImageFileDescriptor's __get__ method, which
# coerces the assigned value into an instance of self.attr_class
# (ImageFieldFile in this case).
file = getattr(instance, self.attname)
# Nothing to update if we have no file and not being forced to update.
if not file and not force:
return
dimension_fields_filled = not (
(self.width_field and not getattr(instance, self.width_field))
or (self.height_field and not getattr(instance, self.height_field))
)
# When both dimension fields have values, we are most likely loading
# data from the database or updating an image field that already had
# an image stored. In the first case, we don't want to update the
# dimension fields because we are already getting their values from the
# database. In the second case, we do want to update the dimensions
# fields and will skip this return because force will be True since we
# were called from ImageFileDescriptor.__set__.
if dimension_fields_filled and not force:
return
# file should be an instance of ImageFieldFile or should be None.
if file:
width = file.width
height = file.height
else:
# No file, so clear dimensions fields.
width = None
height = None
# Update the width and height fields.
if self.width_field:
setattr(instance, self.width_field, width)
if self.height_field:
setattr(instance, self.height_field, height)
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.ImageField,
**kwargs,
}
)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/files.py
|
Python
|
mit
| 18,842 |
import json
import warnings
from django import forms
from django.core import checks, exceptions
from django.db import NotSupportedError, connections, router
from django.db.models import expressions, lookups
from django.db.models.constants import LOOKUP_SEP
from django.db.models.fields import TextField
from django.db.models.lookups import (
FieldGetDbPrepValueMixin,
PostgresOperatorLookup,
Transform,
)
from django.utils.deprecation import RemovedInDjango51Warning
from django.utils.translation import gettext_lazy as _
from . import Field
from .mixins import CheckFieldDefaultMixin
__all__ = ["JSONField"]
class JSONField(CheckFieldDefaultMixin, Field):
empty_strings_allowed = False
description = _("A JSON object")
default_error_messages = {
"invalid": _("Value must be valid JSON."),
}
_default_hint = ("dict", "{}")
def __init__(
self,
verbose_name=None,
name=None,
encoder=None,
decoder=None,
**kwargs,
):
if encoder and not callable(encoder):
raise ValueError("The encoder parameter must be a callable object.")
if decoder and not callable(decoder):
raise ValueError("The decoder parameter must be a callable object.")
self.encoder = encoder
self.decoder = decoder
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
errors = super().check(**kwargs)
databases = kwargs.get("databases") or []
errors.extend(self._check_supported(databases))
return errors
def _check_supported(self, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if (
self.model._meta.required_db_vendor
and self.model._meta.required_db_vendor != connection.vendor
):
continue
if not (
"supports_json_field" in self.model._meta.required_db_features
or connection.features.supports_json_field
):
errors.append(
checks.Error(
"%s does not support JSONFields." % connection.display_name,
obj=self.model,
id="fields.E180",
)
)
return errors
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.encoder is not None:
kwargs["encoder"] = self.encoder
if self.decoder is not None:
kwargs["decoder"] = self.decoder
return name, path, args, kwargs
def from_db_value(self, value, expression, connection):
if value is None:
return value
# Some backends (SQLite at least) extract non-string values in their
# SQL datatypes.
if isinstance(expression, KeyTransform) and not isinstance(value, str):
return value
try:
return json.loads(value, cls=self.decoder)
except json.JSONDecodeError:
return value
def get_internal_type(self):
return "JSONField"
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
# RemovedInDjango51Warning: When the deprecation ends, replace with:
# if (
# isinstance(value, expressions.Value)
# and isinstance(value.output_field, JSONField)
# ):
# value = value.value
# elif hasattr(value, "as_sql"): ...
if isinstance(value, expressions.Value):
if isinstance(value.value, str) and not isinstance(
value.output_field, JSONField
):
try:
value = json.loads(value.value, cls=self.decoder)
except json.JSONDecodeError:
value = value.value
else:
warnings.warn(
"Providing an encoded JSON string via Value() is deprecated. "
f"Use Value({value!r}, output_field=JSONField()) instead.",
category=RemovedInDjango51Warning,
)
elif isinstance(value.output_field, JSONField):
value = value.value
else:
return value
elif hasattr(value, "as_sql"):
return value
return connection.ops.adapt_json_value(value, self.encoder)
def get_db_prep_save(self, value, connection):
if value is None:
return value
return self.get_db_prep_value(value, connection)
def get_transform(self, name):
transform = super().get_transform(name)
if transform:
return transform
return KeyTransformFactory(name)
def validate(self, value, model_instance):
super().validate(value, model_instance)
try:
json.dumps(value, cls=self.encoder)
except TypeError:
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def value_to_string(self, obj):
return self.value_from_object(obj)
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.JSONField,
"encoder": self.encoder,
"decoder": self.decoder,
**kwargs,
}
)
def compile_json_path(key_transforms, include_root=True):
path = ["$"] if include_root else []
for key_transform in key_transforms:
try:
num = int(key_transform)
except ValueError: # non-integer
path.append(".")
path.append(json.dumps(key_transform))
else:
path.append("[%s]" % num)
return "".join(path)
class DataContains(FieldGetDbPrepValueMixin, PostgresOperatorLookup):
lookup_name = "contains"
postgres_operator = "@>"
def as_sql(self, compiler, connection):
if not connection.features.supports_json_field_contains:
raise NotSupportedError(
"contains lookup is not supported on this database backend."
)
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
params = tuple(lhs_params) + tuple(rhs_params)
return "JSON_CONTAINS(%s, %s)" % (lhs, rhs), params
class ContainedBy(FieldGetDbPrepValueMixin, PostgresOperatorLookup):
lookup_name = "contained_by"
postgres_operator = "<@"
def as_sql(self, compiler, connection):
if not connection.features.supports_json_field_contains:
raise NotSupportedError(
"contained_by lookup is not supported on this database backend."
)
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
params = tuple(rhs_params) + tuple(lhs_params)
return "JSON_CONTAINS(%s, %s)" % (rhs, lhs), params
class HasKeyLookup(PostgresOperatorLookup):
logical_operator = None
def compile_json_path_final_key(self, key_transform):
# Compile the final key without interpreting ints as array elements.
return ".%s" % json.dumps(key_transform)
def as_sql(self, compiler, connection, template=None):
# Process JSON path from the left-hand side.
if isinstance(self.lhs, KeyTransform):
lhs, lhs_params, lhs_key_transforms = self.lhs.preprocess_lhs(
compiler, connection
)
lhs_json_path = compile_json_path(lhs_key_transforms)
else:
lhs, lhs_params = self.process_lhs(compiler, connection)
lhs_json_path = "$"
sql = template % lhs
# Process JSON path from the right-hand side.
rhs = self.rhs
rhs_params = []
if not isinstance(rhs, (list, tuple)):
rhs = [rhs]
for key in rhs:
if isinstance(key, KeyTransform):
*_, rhs_key_transforms = key.preprocess_lhs(compiler, connection)
else:
rhs_key_transforms = [key]
*rhs_key_transforms, final_key = rhs_key_transforms
rhs_json_path = compile_json_path(rhs_key_transforms, include_root=False)
rhs_json_path += self.compile_json_path_final_key(final_key)
rhs_params.append(lhs_json_path + rhs_json_path)
# Add condition for each key.
if self.logical_operator:
sql = "(%s)" % self.logical_operator.join([sql] * len(rhs_params))
return sql, tuple(lhs_params) + tuple(rhs_params)
def as_mysql(self, compiler, connection):
return self.as_sql(
compiler, connection, template="JSON_CONTAINS_PATH(%s, 'one', %%s)"
)
def as_oracle(self, compiler, connection):
sql, params = self.as_sql(
compiler, connection, template="JSON_EXISTS(%s, '%%s')"
)
# Add paths directly into SQL because path expressions cannot be passed
# as bind variables on Oracle.
return sql % tuple(params), []
def as_postgresql(self, compiler, connection):
if isinstance(self.rhs, KeyTransform):
*_, rhs_key_transforms = self.rhs.preprocess_lhs(compiler, connection)
for key in rhs_key_transforms[:-1]:
self.lhs = KeyTransform(key, self.lhs)
self.rhs = rhs_key_transforms[-1]
return super().as_postgresql(compiler, connection)
def as_sqlite(self, compiler, connection):
return self.as_sql(
compiler, connection, template="JSON_TYPE(%s, %%s) IS NOT NULL"
)
class HasKey(HasKeyLookup):
lookup_name = "has_key"
postgres_operator = "?"
prepare_rhs = False
class HasKeys(HasKeyLookup):
lookup_name = "has_keys"
postgres_operator = "?&"
logical_operator = " AND "
def get_prep_lookup(self):
return [str(item) for item in self.rhs]
class HasAnyKeys(HasKeys):
lookup_name = "has_any_keys"
postgres_operator = "?|"
logical_operator = " OR "
class HasKeyOrArrayIndex(HasKey):
def compile_json_path_final_key(self, key_transform):
return compile_json_path([key_transform], include_root=False)
class CaseInsensitiveMixin:
"""
Mixin to allow case-insensitive comparison of JSON values on MySQL.
MySQL handles strings used in JSON context using the utf8mb4_bin collation.
Because utf8mb4_bin is a binary collation, comparison of JSON values is
case-sensitive.
"""
def process_lhs(self, compiler, connection):
lhs, lhs_params = super().process_lhs(compiler, connection)
if connection.vendor == "mysql":
return "LOWER(%s)" % lhs, lhs_params
return lhs, lhs_params
def process_rhs(self, compiler, connection):
rhs, rhs_params = super().process_rhs(compiler, connection)
if connection.vendor == "mysql":
return "LOWER(%s)" % rhs, rhs_params
return rhs, rhs_params
class JSONExact(lookups.Exact):
can_use_none_as_rhs = True
def process_rhs(self, compiler, connection):
rhs, rhs_params = super().process_rhs(compiler, connection)
# Treat None lookup values as null.
if rhs == "%s" and rhs_params == [None]:
rhs_params = ["null"]
if connection.vendor == "mysql":
func = ["JSON_EXTRACT(%s, '$')"] * len(rhs_params)
rhs %= tuple(func)
return rhs, rhs_params
class JSONIContains(CaseInsensitiveMixin, lookups.IContains):
pass
JSONField.register_lookup(DataContains)
JSONField.register_lookup(ContainedBy)
JSONField.register_lookup(HasKey)
JSONField.register_lookup(HasKeys)
JSONField.register_lookup(HasAnyKeys)
JSONField.register_lookup(JSONExact)
JSONField.register_lookup(JSONIContains)
class KeyTransform(Transform):
postgres_operator = "->"
postgres_nested_operator = "#>"
def __init__(self, key_name, *args, **kwargs):
super().__init__(*args, **kwargs)
self.key_name = str(key_name)
def preprocess_lhs(self, compiler, connection):
key_transforms = [self.key_name]
previous = self.lhs
while isinstance(previous, KeyTransform):
key_transforms.insert(0, previous.key_name)
previous = previous.lhs
lhs, params = compiler.compile(previous)
if connection.vendor == "oracle":
# Escape string-formatting.
key_transforms = [key.replace("%", "%%") for key in key_transforms]
return lhs, params, key_transforms
def as_mysql(self, compiler, connection):
lhs, params, key_transforms = self.preprocess_lhs(compiler, connection)
json_path = compile_json_path(key_transforms)
return "JSON_EXTRACT(%s, %%s)" % lhs, tuple(params) + (json_path,)
def as_oracle(self, compiler, connection):
lhs, params, key_transforms = self.preprocess_lhs(compiler, connection)
json_path = compile_json_path(key_transforms)
return (
"COALESCE(JSON_QUERY(%s, '%s'), JSON_VALUE(%s, '%s'))"
% ((lhs, json_path) * 2)
), tuple(params) * 2
def as_postgresql(self, compiler, connection):
lhs, params, key_transforms = self.preprocess_lhs(compiler, connection)
if len(key_transforms) > 1:
sql = "(%s %s %%s)" % (lhs, self.postgres_nested_operator)
return sql, tuple(params) + (key_transforms,)
try:
lookup = int(self.key_name)
except ValueError:
lookup = self.key_name
return "(%s %s %%s)" % (lhs, self.postgres_operator), tuple(params) + (lookup,)
def as_sqlite(self, compiler, connection):
lhs, params, key_transforms = self.preprocess_lhs(compiler, connection)
json_path = compile_json_path(key_transforms)
datatype_values = ",".join(
[repr(datatype) for datatype in connection.ops.jsonfield_datatype_values]
)
return (
"(CASE WHEN JSON_TYPE(%s, %%s) IN (%s) "
"THEN JSON_TYPE(%s, %%s) ELSE JSON_EXTRACT(%s, %%s) END)"
) % (lhs, datatype_values, lhs, lhs), (tuple(params) + (json_path,)) * 3
class KeyTextTransform(KeyTransform):
postgres_operator = "->>"
postgres_nested_operator = "#>>"
output_field = TextField()
def as_mysql(self, compiler, connection):
if connection.mysql_is_mariadb:
# MariaDB doesn't support -> and ->> operators (see MDEV-13594).
sql, params = super().as_mysql(compiler, connection)
return "JSON_UNQUOTE(%s)" % sql, params
else:
lhs, params, key_transforms = self.preprocess_lhs(compiler, connection)
json_path = compile_json_path(key_transforms)
return "(%s ->> %%s)" % lhs, tuple(params) + (json_path,)
@classmethod
def from_lookup(cls, lookup):
transform, *keys = lookup.split(LOOKUP_SEP)
if not keys:
raise ValueError("Lookup must contain key or index transforms.")
for key in keys:
transform = cls(key, transform)
return transform
KT = KeyTextTransform.from_lookup
class KeyTransformTextLookupMixin:
"""
Mixin for combining with a lookup expecting a text lhs from a JSONField
key lookup. On PostgreSQL, make use of the ->> operator instead of casting
key values to text and performing the lookup on the resulting
representation.
"""
def __init__(self, key_transform, *args, **kwargs):
if not isinstance(key_transform, KeyTransform):
raise TypeError(
"Transform should be an instance of KeyTransform in order to "
"use this lookup."
)
key_text_transform = KeyTextTransform(
key_transform.key_name,
*key_transform.source_expressions,
**key_transform.extra,
)
super().__init__(key_text_transform, *args, **kwargs)
class KeyTransformIsNull(lookups.IsNull):
# key__isnull=False is the same as has_key='key'
def as_oracle(self, compiler, connection):
sql, params = HasKeyOrArrayIndex(
self.lhs.lhs,
self.lhs.key_name,
).as_oracle(compiler, connection)
if not self.rhs:
return sql, params
# Column doesn't have a key or IS NULL.
lhs, lhs_params, _ = self.lhs.preprocess_lhs(compiler, connection)
return "(NOT %s OR %s IS NULL)" % (sql, lhs), tuple(params) + tuple(lhs_params)
def as_sqlite(self, compiler, connection):
template = "JSON_TYPE(%s, %%s) IS NULL"
if not self.rhs:
template = "JSON_TYPE(%s, %%s) IS NOT NULL"
return HasKeyOrArrayIndex(self.lhs.lhs, self.lhs.key_name).as_sql(
compiler,
connection,
template=template,
)
class KeyTransformIn(lookups.In):
def resolve_expression_parameter(self, compiler, connection, sql, param):
sql, params = super().resolve_expression_parameter(
compiler,
connection,
sql,
param,
)
if (
not hasattr(param, "as_sql")
and not connection.features.has_native_json_field
):
if connection.vendor == "oracle":
value = json.loads(param)
sql = "%s(JSON_OBJECT('value' VALUE %%s FORMAT JSON), '$.value')"
if isinstance(value, (list, dict)):
sql %= "JSON_QUERY"
else:
sql %= "JSON_VALUE"
elif connection.vendor == "mysql" or (
connection.vendor == "sqlite"
and params[0] not in connection.ops.jsonfield_datatype_values
):
sql = "JSON_EXTRACT(%s, '$')"
if connection.vendor == "mysql" and connection.mysql_is_mariadb:
sql = "JSON_UNQUOTE(%s)" % sql
return sql, params
class KeyTransformExact(JSONExact):
def process_rhs(self, compiler, connection):
if isinstance(self.rhs, KeyTransform):
return super(lookups.Exact, self).process_rhs(compiler, connection)
rhs, rhs_params = super().process_rhs(compiler, connection)
if connection.vendor == "oracle":
func = []
sql = "%s(JSON_OBJECT('value' VALUE %%s FORMAT JSON), '$.value')"
for value in rhs_params:
value = json.loads(value)
if isinstance(value, (list, dict)):
func.append(sql % "JSON_QUERY")
else:
func.append(sql % "JSON_VALUE")
rhs %= tuple(func)
elif connection.vendor == "sqlite":
func = []
for value in rhs_params:
if value in connection.ops.jsonfield_datatype_values:
func.append("%s")
else:
func.append("JSON_EXTRACT(%s, '$')")
rhs %= tuple(func)
return rhs, rhs_params
def as_oracle(self, compiler, connection):
rhs, rhs_params = super().process_rhs(compiler, connection)
if rhs_params == ["null"]:
# Field has key and it's NULL.
has_key_expr = HasKeyOrArrayIndex(self.lhs.lhs, self.lhs.key_name)
has_key_sql, has_key_params = has_key_expr.as_oracle(compiler, connection)
is_null_expr = self.lhs.get_lookup("isnull")(self.lhs, True)
is_null_sql, is_null_params = is_null_expr.as_sql(compiler, connection)
return (
"%s AND %s" % (has_key_sql, is_null_sql),
tuple(has_key_params) + tuple(is_null_params),
)
return super().as_sql(compiler, connection)
class KeyTransformIExact(
CaseInsensitiveMixin, KeyTransformTextLookupMixin, lookups.IExact
):
pass
class KeyTransformIContains(
CaseInsensitiveMixin, KeyTransformTextLookupMixin, lookups.IContains
):
pass
class KeyTransformStartsWith(KeyTransformTextLookupMixin, lookups.StartsWith):
pass
class KeyTransformIStartsWith(
CaseInsensitiveMixin, KeyTransformTextLookupMixin, lookups.IStartsWith
):
pass
class KeyTransformEndsWith(KeyTransformTextLookupMixin, lookups.EndsWith):
pass
class KeyTransformIEndsWith(
CaseInsensitiveMixin, KeyTransformTextLookupMixin, lookups.IEndsWith
):
pass
class KeyTransformRegex(KeyTransformTextLookupMixin, lookups.Regex):
pass
class KeyTransformIRegex(
CaseInsensitiveMixin, KeyTransformTextLookupMixin, lookups.IRegex
):
pass
class KeyTransformNumericLookupMixin:
def process_rhs(self, compiler, connection):
rhs, rhs_params = super().process_rhs(compiler, connection)
if not connection.features.has_native_json_field:
rhs_params = [json.loads(value) for value in rhs_params]
return rhs, rhs_params
class KeyTransformLt(KeyTransformNumericLookupMixin, lookups.LessThan):
pass
class KeyTransformLte(KeyTransformNumericLookupMixin, lookups.LessThanOrEqual):
pass
class KeyTransformGt(KeyTransformNumericLookupMixin, lookups.GreaterThan):
pass
class KeyTransformGte(KeyTransformNumericLookupMixin, lookups.GreaterThanOrEqual):
pass
KeyTransform.register_lookup(KeyTransformIn)
KeyTransform.register_lookup(KeyTransformExact)
KeyTransform.register_lookup(KeyTransformIExact)
KeyTransform.register_lookup(KeyTransformIsNull)
KeyTransform.register_lookup(KeyTransformIContains)
KeyTransform.register_lookup(KeyTransformStartsWith)
KeyTransform.register_lookup(KeyTransformIStartsWith)
KeyTransform.register_lookup(KeyTransformEndsWith)
KeyTransform.register_lookup(KeyTransformIEndsWith)
KeyTransform.register_lookup(KeyTransformRegex)
KeyTransform.register_lookup(KeyTransformIRegex)
KeyTransform.register_lookup(KeyTransformLt)
KeyTransform.register_lookup(KeyTransformLte)
KeyTransform.register_lookup(KeyTransformGt)
KeyTransform.register_lookup(KeyTransformGte)
class KeyTransformFactory:
def __init__(self, key_name):
self.key_name = key_name
def __call__(self, *args, **kwargs):
return KeyTransform(self.key_name, *args, **kwargs)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/json.py
|
Python
|
mit
| 22,508 |
from django.core import checks
NOT_PROVIDED = object()
class FieldCacheMixin:
"""Provide an API for working with the model's fields value cache."""
def get_cache_name(self):
raise NotImplementedError
def get_cached_value(self, instance, default=NOT_PROVIDED):
cache_name = self.get_cache_name()
try:
return instance._state.fields_cache[cache_name]
except KeyError:
if default is NOT_PROVIDED:
raise
return default
def is_cached(self, instance):
return self.get_cache_name() in instance._state.fields_cache
def set_cached_value(self, instance, value):
instance._state.fields_cache[self.get_cache_name()] = value
def delete_cached_value(self, instance):
del instance._state.fields_cache[self.get_cache_name()]
class CheckFieldDefaultMixin:
_default_hint = ("<valid default>", "<invalid default>")
def _check_default(self):
if (
self.has_default()
and self.default is not None
and not callable(self.default)
):
return [
checks.Warning(
"%s default should be a callable instead of an instance "
"so that it's not shared between all field instances."
% (self.__class__.__name__,),
hint=(
"Use a callable instead, e.g., use `%s` instead of "
"`%s`." % self._default_hint
),
obj=self,
id="fields.E010",
)
]
else:
return []
def check(self, **kwargs):
errors = super().check(**kwargs)
errors.extend(self._check_default())
return errors
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/mixins.py
|
Python
|
mit
| 1,823 |
"""
Field-like classes that aren't really fields. It's easier to use objects that
have the same attributes as fields sometimes (avoids a lot of special casing).
"""
from django.db.models import fields
class OrderWrt(fields.IntegerField):
"""
A proxy for the _order database field that is used when
Meta.order_with_respect_to is specified.
"""
def __init__(self, *args, **kwargs):
kwargs["name"] = "_order"
kwargs["editable"] = False
super().__init__(*args, **kwargs)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/proxy.py
|
Python
|
mit
| 515 |
import functools
import inspect
from functools import partial
from django import forms
from django.apps import apps
from django.conf import SettingsReference, settings
from django.core import checks, exceptions
from django.db import connection, router
from django.db.backends import utils
from django.db.models import Q
from django.db.models.constants import LOOKUP_SEP
from django.db.models.deletion import CASCADE, SET_DEFAULT, SET_NULL
from django.db.models.query_utils import PathInfo
from django.db.models.utils import make_model_tuple
from django.utils.functional import cached_property
from django.utils.translation import gettext_lazy as _
from . import Field
from .mixins import FieldCacheMixin
from .related_descriptors import (
ForeignKeyDeferredAttribute,
ForwardManyToOneDescriptor,
ForwardOneToOneDescriptor,
ManyToManyDescriptor,
ReverseManyToOneDescriptor,
ReverseOneToOneDescriptor,
)
from .related_lookups import (
RelatedExact,
RelatedGreaterThan,
RelatedGreaterThanOrEqual,
RelatedIn,
RelatedIsNull,
RelatedLessThan,
RelatedLessThanOrEqual,
)
from .reverse_related import ForeignObjectRel, ManyToManyRel, ManyToOneRel, OneToOneRel
RECURSIVE_RELATIONSHIP_CONSTANT = "self"
def resolve_relation(scope_model, relation):
"""
Transform relation into a model or fully-qualified model string of the form
"app_label.ModelName", relative to scope_model.
The relation argument can be:
* RECURSIVE_RELATIONSHIP_CONSTANT, i.e. the string "self", in which case
the model argument will be returned.
* A bare model name without an app_label, in which case scope_model's
app_label will be prepended.
* An "app_label.ModelName" string.
* A model class, which will be returned unchanged.
"""
# Check for recursive relations
if relation == RECURSIVE_RELATIONSHIP_CONSTANT:
relation = scope_model
# Look for an "app.Model" relation
if isinstance(relation, str):
if "." not in relation:
relation = "%s.%s" % (scope_model._meta.app_label, relation)
return relation
def lazy_related_operation(function, model, *related_models, **kwargs):
"""
Schedule `function` to be called once `model` and all `related_models`
have been imported and registered with the app registry. `function` will
be called with the newly-loaded model classes as its positional arguments,
plus any optional keyword arguments.
The `model` argument must be a model class. Each subsequent positional
argument is another model, or a reference to another model - see
`resolve_relation()` for the various forms these may take. Any relative
references will be resolved relative to `model`.
This is a convenience wrapper for `Apps.lazy_model_operation` - the app
registry model used is the one found in `model._meta.apps`.
"""
models = [model] + [resolve_relation(model, rel) for rel in related_models]
model_keys = (make_model_tuple(m) for m in models)
apps = model._meta.apps
return apps.lazy_model_operation(partial(function, **kwargs), *model_keys)
class RelatedField(FieldCacheMixin, Field):
"""Base class that all relational fields inherit from."""
# Field flags
one_to_many = False
one_to_one = False
many_to_many = False
many_to_one = False
def __init__(
self,
related_name=None,
related_query_name=None,
limit_choices_to=None,
**kwargs,
):
self._related_name = related_name
self._related_query_name = related_query_name
self._limit_choices_to = limit_choices_to
super().__init__(**kwargs)
@cached_property
def related_model(self):
# Can't cache this property until all the models are loaded.
apps.check_models_ready()
return self.remote_field.model
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_related_name_is_valid(),
*self._check_related_query_name_is_valid(),
*self._check_relation_model_exists(),
*self._check_referencing_to_swapped_model(),
*self._check_clashes(),
]
def _check_related_name_is_valid(self):
import keyword
related_name = self.remote_field.related_name
if related_name is None:
return []
is_valid_id = (
not keyword.iskeyword(related_name) and related_name.isidentifier()
)
if not (is_valid_id or related_name.endswith("+")):
return [
checks.Error(
"The name '%s' is invalid related_name for field %s.%s"
% (
self.remote_field.related_name,
self.model._meta.object_name,
self.name,
),
hint=(
"Related name must be a valid Python identifier or end with a "
"'+'"
),
obj=self,
id="fields.E306",
)
]
return []
def _check_related_query_name_is_valid(self):
if self.remote_field.is_hidden():
return []
rel_query_name = self.related_query_name()
errors = []
if rel_query_name.endswith("_"):
errors.append(
checks.Error(
"Reverse query name '%s' must not end with an underscore."
% rel_query_name,
hint=(
"Add or change a related_name or related_query_name "
"argument for this field."
),
obj=self,
id="fields.E308",
)
)
if LOOKUP_SEP in rel_query_name:
errors.append(
checks.Error(
"Reverse query name '%s' must not contain '%s'."
% (rel_query_name, LOOKUP_SEP),
hint=(
"Add or change a related_name or related_query_name "
"argument for this field."
),
obj=self,
id="fields.E309",
)
)
return errors
def _check_relation_model_exists(self):
rel_is_missing = self.remote_field.model not in self.opts.apps.get_models()
rel_is_string = isinstance(self.remote_field.model, str)
model_name = (
self.remote_field.model
if rel_is_string
else self.remote_field.model._meta.object_name
)
if rel_is_missing and (
rel_is_string or not self.remote_field.model._meta.swapped
):
return [
checks.Error(
"Field defines a relation with model '%s', which is either "
"not installed, or is abstract." % model_name,
obj=self,
id="fields.E300",
)
]
return []
def _check_referencing_to_swapped_model(self):
if (
self.remote_field.model not in self.opts.apps.get_models()
and not isinstance(self.remote_field.model, str)
and self.remote_field.model._meta.swapped
):
return [
checks.Error(
"Field defines a relation with the model '%s', which has "
"been swapped out." % self.remote_field.model._meta.label,
hint="Update the relation to point at 'settings.%s'."
% self.remote_field.model._meta.swappable,
obj=self,
id="fields.E301",
)
]
return []
def _check_clashes(self):
"""Check accessor and reverse query name clashes."""
from django.db.models.base import ModelBase
errors = []
opts = self.model._meta
# f.remote_field.model may be a string instead of a model. Skip if
# model name is not resolved.
if not isinstance(self.remote_field.model, ModelBase):
return []
# Consider that we are checking field `Model.foreign` and the models
# are:
#
# class Target(models.Model):
# model = models.IntegerField()
# model_set = models.IntegerField()
#
# class Model(models.Model):
# foreign = models.ForeignKey(Target)
# m2m = models.ManyToManyField(Target)
# rel_opts.object_name == "Target"
rel_opts = self.remote_field.model._meta
# If the field doesn't install a backward relation on the target model
# (so `is_hidden` returns True), then there are no clashes to check
# and we can skip these fields.
rel_is_hidden = self.remote_field.is_hidden()
rel_name = self.remote_field.get_accessor_name() # i. e. "model_set"
rel_query_name = self.related_query_name() # i. e. "model"
# i.e. "app_label.Model.field".
field_name = "%s.%s" % (opts.label, self.name)
# Check clashes between accessor or reverse query name of `field`
# and any other field name -- i.e. accessor for Model.foreign is
# model_set and it clashes with Target.model_set.
potential_clashes = rel_opts.fields + rel_opts.many_to_many
for clash_field in potential_clashes:
# i.e. "app_label.Target.model_set".
clash_name = "%s.%s" % (rel_opts.label, clash_field.name)
if not rel_is_hidden and clash_field.name == rel_name:
errors.append(
checks.Error(
f"Reverse accessor '{rel_opts.object_name}.{rel_name}' "
f"for '{field_name}' clashes with field name "
f"'{clash_name}'.",
hint=(
"Rename field '%s', or add/change a related_name "
"argument to the definition for field '%s'."
)
% (clash_name, field_name),
obj=self,
id="fields.E302",
)
)
if clash_field.name == rel_query_name:
errors.append(
checks.Error(
"Reverse query name for '%s' clashes with field name '%s'."
% (field_name, clash_name),
hint=(
"Rename field '%s', or add/change a related_name "
"argument to the definition for field '%s'."
)
% (clash_name, field_name),
obj=self,
id="fields.E303",
)
)
# Check clashes between accessors/reverse query names of `field` and
# any other field accessor -- i. e. Model.foreign accessor clashes with
# Model.m2m accessor.
potential_clashes = (r for r in rel_opts.related_objects if r.field is not self)
for clash_field in potential_clashes:
# i.e. "app_label.Model.m2m".
clash_name = "%s.%s" % (
clash_field.related_model._meta.label,
clash_field.field.name,
)
if not rel_is_hidden and clash_field.get_accessor_name() == rel_name:
errors.append(
checks.Error(
f"Reverse accessor '{rel_opts.object_name}.{rel_name}' "
f"for '{field_name}' clashes with reverse accessor for "
f"'{clash_name}'.",
hint=(
"Add or change a related_name argument "
"to the definition for '%s' or '%s'."
)
% (field_name, clash_name),
obj=self,
id="fields.E304",
)
)
if clash_field.get_accessor_name() == rel_query_name:
errors.append(
checks.Error(
"Reverse query name for '%s' clashes with reverse query name "
"for '%s'." % (field_name, clash_name),
hint=(
"Add or change a related_name argument "
"to the definition for '%s' or '%s'."
)
% (field_name, clash_name),
obj=self,
id="fields.E305",
)
)
return errors
def db_type(self, connection):
# By default related field will not have a column as it relates to
# columns from another table.
return None
def contribute_to_class(self, cls, name, private_only=False, **kwargs):
super().contribute_to_class(cls, name, private_only=private_only, **kwargs)
self.opts = cls._meta
if not cls._meta.abstract:
if self.remote_field.related_name:
related_name = self.remote_field.related_name
else:
related_name = self.opts.default_related_name
if related_name:
related_name %= {
"class": cls.__name__.lower(),
"model_name": cls._meta.model_name.lower(),
"app_label": cls._meta.app_label.lower(),
}
self.remote_field.related_name = related_name
if self.remote_field.related_query_name:
related_query_name = self.remote_field.related_query_name % {
"class": cls.__name__.lower(),
"app_label": cls._meta.app_label.lower(),
}
self.remote_field.related_query_name = related_query_name
def resolve_related_class(model, related, field):
field.remote_field.model = related
field.do_related_class(related, model)
lazy_related_operation(
resolve_related_class, cls, self.remote_field.model, field=self
)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self._limit_choices_to:
kwargs["limit_choices_to"] = self._limit_choices_to
if self._related_name is not None:
kwargs["related_name"] = self._related_name
if self._related_query_name is not None:
kwargs["related_query_name"] = self._related_query_name
return name, path, args, kwargs
def get_forward_related_filter(self, obj):
"""
Return the keyword arguments that when supplied to
self.model.object.filter(), would select all instances related through
this field to the remote obj. This is used to build the querysets
returned by related descriptors. obj is an instance of
self.related_field.model.
"""
return {
"%s__%s" % (self.name, rh_field.name): getattr(obj, rh_field.attname)
for _, rh_field in self.related_fields
}
def get_reverse_related_filter(self, obj):
"""
Complement to get_forward_related_filter(). Return the keyword
arguments that when passed to self.related_field.model.object.filter()
select all instances of self.related_field.model related through
this field to obj. obj is an instance of self.model.
"""
base_q = Q.create(
[
(rh_field.attname, getattr(obj, lh_field.attname))
for lh_field, rh_field in self.related_fields
]
)
descriptor_filter = self.get_extra_descriptor_filter(obj)
if isinstance(descriptor_filter, dict):
return base_q & Q(**descriptor_filter)
elif descriptor_filter:
return base_q & descriptor_filter
return base_q
@property
def swappable_setting(self):
"""
Get the setting that this is powered from for swapping, or None
if it's not swapped in / marked with swappable=False.
"""
if self.swappable:
# Work out string form of "to"
if isinstance(self.remote_field.model, str):
to_string = self.remote_field.model
else:
to_string = self.remote_field.model._meta.label
return apps.get_swappable_settings_name(to_string)
return None
def set_attributes_from_rel(self):
self.name = self.name or (
self.remote_field.model._meta.model_name
+ "_"
+ self.remote_field.model._meta.pk.name
)
if self.verbose_name is None:
self.verbose_name = self.remote_field.model._meta.verbose_name
self.remote_field.set_field_name()
def do_related_class(self, other, cls):
self.set_attributes_from_rel()
self.contribute_to_related_class(other, self.remote_field)
def get_limit_choices_to(self):
"""
Return ``limit_choices_to`` for this model field.
If it is a callable, it will be invoked and the result will be
returned.
"""
if callable(self.remote_field.limit_choices_to):
return self.remote_field.limit_choices_to()
return self.remote_field.limit_choices_to
def formfield(self, **kwargs):
"""
Pass ``limit_choices_to`` to the field being constructed.
Only passes it if there is a type that supports related fields.
This is a similar strategy used to pass the ``queryset`` to the field
being constructed.
"""
defaults = {}
if hasattr(self.remote_field, "get_related_field"):
# If this is a callable, do not invoke it here. Just pass
# it in the defaults for when the form class will later be
# instantiated.
limit_choices_to = self.remote_field.limit_choices_to
defaults.update(
{
"limit_choices_to": limit_choices_to,
}
)
defaults.update(kwargs)
return super().formfield(**defaults)
def related_query_name(self):
"""
Define the name that can be used to identify this related object in a
table-spanning query.
"""
return (
self.remote_field.related_query_name
or self.remote_field.related_name
or self.opts.model_name
)
@property
def target_field(self):
"""
When filtering against this relation, return the field on the remote
model against which the filtering should happen.
"""
target_fields = self.path_infos[-1].target_fields
if len(target_fields) > 1:
raise exceptions.FieldError(
"The relation has multiple target fields, but only single target field "
"was asked for"
)
return target_fields[0]
def get_cache_name(self):
return self.name
class ForeignObject(RelatedField):
"""
Abstraction of the ForeignKey relation to support multi-column relations.
"""
# Field flags
many_to_many = False
many_to_one = True
one_to_many = False
one_to_one = False
requires_unique_target = True
related_accessor_class = ReverseManyToOneDescriptor
forward_related_accessor_class = ForwardManyToOneDescriptor
rel_class = ForeignObjectRel
def __init__(
self,
to,
on_delete,
from_fields,
to_fields,
rel=None,
related_name=None,
related_query_name=None,
limit_choices_to=None,
parent_link=False,
swappable=True,
**kwargs,
):
if rel is None:
rel = self.rel_class(
self,
to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
super().__init__(
rel=rel,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
**kwargs,
)
self.from_fields = from_fields
self.to_fields = to_fields
self.swappable = swappable
def __copy__(self):
obj = super().__copy__()
# Remove any cached PathInfo values.
obj.__dict__.pop("path_infos", None)
obj.__dict__.pop("reverse_path_infos", None)
return obj
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_to_fields_exist(),
*self._check_unique_target(),
]
def _check_to_fields_exist(self):
# Skip nonexistent models.
if isinstance(self.remote_field.model, str):
return []
errors = []
for to_field in self.to_fields:
if to_field:
try:
self.remote_field.model._meta.get_field(to_field)
except exceptions.FieldDoesNotExist:
errors.append(
checks.Error(
"The to_field '%s' doesn't exist on the related "
"model '%s'."
% (to_field, self.remote_field.model._meta.label),
obj=self,
id="fields.E312",
)
)
return errors
def _check_unique_target(self):
rel_is_string = isinstance(self.remote_field.model, str)
if rel_is_string or not self.requires_unique_target:
return []
try:
self.foreign_related_fields
except exceptions.FieldDoesNotExist:
return []
if not self.foreign_related_fields:
return []
unique_foreign_fields = {
frozenset([f.name])
for f in self.remote_field.model._meta.get_fields()
if getattr(f, "unique", False)
}
unique_foreign_fields.update(
{frozenset(ut) for ut in self.remote_field.model._meta.unique_together}
)
unique_foreign_fields.update(
{
frozenset(uc.fields)
for uc in self.remote_field.model._meta.total_unique_constraints
}
)
foreign_fields = {f.name for f in self.foreign_related_fields}
has_unique_constraint = any(u <= foreign_fields for u in unique_foreign_fields)
if not has_unique_constraint and len(self.foreign_related_fields) > 1:
field_combination = ", ".join(
"'%s'" % rel_field.name for rel_field in self.foreign_related_fields
)
model_name = self.remote_field.model.__name__
return [
checks.Error(
"No subset of the fields %s on model '%s' is unique."
% (field_combination, model_name),
hint=(
"Mark a single field as unique=True or add a set of "
"fields to a unique constraint (via unique_together "
"or a UniqueConstraint (without condition) in the "
"model Meta.constraints)."
),
obj=self,
id="fields.E310",
)
]
elif not has_unique_constraint:
field_name = self.foreign_related_fields[0].name
model_name = self.remote_field.model.__name__
return [
checks.Error(
"'%s.%s' must be unique because it is referenced by "
"a foreign key." % (model_name, field_name),
hint=(
"Add unique=True to this field or add a "
"UniqueConstraint (without condition) in the model "
"Meta.constraints."
),
obj=self,
id="fields.E311",
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
kwargs["on_delete"] = self.remote_field.on_delete
kwargs["from_fields"] = self.from_fields
kwargs["to_fields"] = self.to_fields
if self.remote_field.parent_link:
kwargs["parent_link"] = self.remote_field.parent_link
if isinstance(self.remote_field.model, str):
if "." in self.remote_field.model:
app_label, model_name = self.remote_field.model.split(".")
kwargs["to"] = "%s.%s" % (app_label, model_name.lower())
else:
kwargs["to"] = self.remote_field.model.lower()
else:
kwargs["to"] = self.remote_field.model._meta.label_lower
# If swappable is True, then see if we're actually pointing to the target
# of a swap.
swappable_setting = self.swappable_setting
if swappable_setting is not None:
# If it's already a settings reference, error
if hasattr(kwargs["to"], "setting_name"):
if kwargs["to"].setting_name != swappable_setting:
raise ValueError(
"Cannot deconstruct a ForeignKey pointing to a model "
"that is swapped in place of more than one model (%s and %s)"
% (kwargs["to"].setting_name, swappable_setting)
)
# Set it
kwargs["to"] = SettingsReference(
kwargs["to"],
swappable_setting,
)
return name, path, args, kwargs
def resolve_related_fields(self):
if not self.from_fields or len(self.from_fields) != len(self.to_fields):
raise ValueError(
"Foreign Object from and to fields must be the same non-zero length"
)
if isinstance(self.remote_field.model, str):
raise ValueError(
"Related model %r cannot be resolved" % self.remote_field.model
)
related_fields = []
for index in range(len(self.from_fields)):
from_field_name = self.from_fields[index]
to_field_name = self.to_fields[index]
from_field = (
self
if from_field_name == RECURSIVE_RELATIONSHIP_CONSTANT
else self.opts.get_field(from_field_name)
)
to_field = (
self.remote_field.model._meta.pk
if to_field_name is None
else self.remote_field.model._meta.get_field(to_field_name)
)
related_fields.append((from_field, to_field))
return related_fields
@cached_property
def related_fields(self):
return self.resolve_related_fields()
@cached_property
def reverse_related_fields(self):
return [(rhs_field, lhs_field) for lhs_field, rhs_field in self.related_fields]
@cached_property
def local_related_fields(self):
return tuple(lhs_field for lhs_field, rhs_field in self.related_fields)
@cached_property
def foreign_related_fields(self):
return tuple(
rhs_field for lhs_field, rhs_field in self.related_fields if rhs_field
)
def get_local_related_value(self, instance):
return self.get_instance_value_for_fields(instance, self.local_related_fields)
def get_foreign_related_value(self, instance):
return self.get_instance_value_for_fields(instance, self.foreign_related_fields)
@staticmethod
def get_instance_value_for_fields(instance, fields):
ret = []
opts = instance._meta
for field in fields:
# Gotcha: in some cases (like fixture loading) a model can have
# different values in parent_ptr_id and parent's id. So, use
# instance.pk (that is, parent_ptr_id) when asked for instance.id.
if field.primary_key:
possible_parent_link = opts.get_ancestor_link(field.model)
if (
not possible_parent_link
or possible_parent_link.primary_key
or possible_parent_link.model._meta.abstract
):
ret.append(instance.pk)
continue
ret.append(getattr(instance, field.attname))
return tuple(ret)
def get_attname_column(self):
attname, column = super().get_attname_column()
return attname, None
def get_joining_columns(self, reverse_join=False):
source = self.reverse_related_fields if reverse_join else self.related_fields
return tuple(
(lhs_field.column, rhs_field.column) for lhs_field, rhs_field in source
)
def get_reverse_joining_columns(self):
return self.get_joining_columns(reverse_join=True)
def get_extra_descriptor_filter(self, instance):
"""
Return an extra filter condition for related object fetching when
user does 'instance.fieldname', that is the extra filter is used in
the descriptor of the field.
The filter should be either a dict usable in .filter(**kwargs) call or
a Q-object. The condition will be ANDed together with the relation's
joining columns.
A parallel method is get_extra_restriction() which is used in
JOIN and subquery conditions.
"""
return {}
def get_extra_restriction(self, alias, related_alias):
"""
Return a pair condition used for joining and subquery pushdown. The
condition is something that responds to as_sql(compiler, connection)
method.
Note that currently referring both the 'alias' and 'related_alias'
will not work in some conditions, like subquery pushdown.
A parallel method is get_extra_descriptor_filter() which is used in
instance.fieldname related object fetching.
"""
return None
def get_path_info(self, filtered_relation=None):
"""Get path from this field to the related model."""
opts = self.remote_field.model._meta
from_opts = self.model._meta
return [
PathInfo(
from_opts=from_opts,
to_opts=opts,
target_fields=self.foreign_related_fields,
join_field=self,
m2m=False,
direct=True,
filtered_relation=filtered_relation,
)
]
@cached_property
def path_infos(self):
return self.get_path_info()
def get_reverse_path_info(self, filtered_relation=None):
"""Get path from the related model to this field's model."""
opts = self.model._meta
from_opts = self.remote_field.model._meta
return [
PathInfo(
from_opts=from_opts,
to_opts=opts,
target_fields=(opts.pk,),
join_field=self.remote_field,
m2m=not self.unique,
direct=False,
filtered_relation=filtered_relation,
)
]
@cached_property
def reverse_path_infos(self):
return self.get_reverse_path_info()
@classmethod
@functools.lru_cache(maxsize=None)
def get_class_lookups(cls):
bases = inspect.getmro(cls)
bases = bases[: bases.index(ForeignObject) + 1]
class_lookups = [parent.__dict__.get("class_lookups", {}) for parent in bases]
return cls.merge_dicts(class_lookups)
def contribute_to_class(self, cls, name, private_only=False, **kwargs):
super().contribute_to_class(cls, name, private_only=private_only, **kwargs)
setattr(cls, self.name, self.forward_related_accessor_class(self))
def contribute_to_related_class(self, cls, related):
# Internal FK's - i.e., those with a related name ending with '+' -
# and swapped models don't get a related descriptor.
if (
not self.remote_field.is_hidden()
and not related.related_model._meta.swapped
):
setattr(
cls._meta.concrete_model,
related.get_accessor_name(),
self.related_accessor_class(related),
)
# While 'limit_choices_to' might be a callable, simply pass
# it along for later - this is too early because it's still
# model load time.
if self.remote_field.limit_choices_to:
cls._meta.related_fkey_lookups.append(
self.remote_field.limit_choices_to
)
ForeignObject.register_lookup(RelatedIn)
ForeignObject.register_lookup(RelatedExact)
ForeignObject.register_lookup(RelatedLessThan)
ForeignObject.register_lookup(RelatedGreaterThan)
ForeignObject.register_lookup(RelatedGreaterThanOrEqual)
ForeignObject.register_lookup(RelatedLessThanOrEqual)
ForeignObject.register_lookup(RelatedIsNull)
class ForeignKey(ForeignObject):
"""
Provide a many-to-one relation by adding a column to the local model
to hold the remote value.
By default ForeignKey will target the pk of the remote model but this
behavior can be changed by using the ``to_field`` argument.
"""
descriptor_class = ForeignKeyDeferredAttribute
# Field flags
many_to_many = False
many_to_one = True
one_to_many = False
one_to_one = False
rel_class = ManyToOneRel
empty_strings_allowed = False
default_error_messages = {
"invalid": _("%(model)s instance with %(field)s %(value)r does not exist.")
}
description = _("Foreign Key (type determined by related field)")
def __init__(
self,
to,
on_delete,
related_name=None,
related_query_name=None,
limit_choices_to=None,
parent_link=False,
to_field=None,
db_constraint=True,
**kwargs,
):
try:
to._meta.model_name
except AttributeError:
if not isinstance(to, str):
raise TypeError(
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r"
% (
self.__class__.__name__,
to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if not callable(on_delete):
raise TypeError("on_delete must be callable.")
kwargs["rel"] = self.rel_class(
self,
to,
to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs.setdefault("db_index", True)
super().__init__(
to,
on_delete,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
from_fields=[RECURSIVE_RELATIONSHIP_CONSTANT],
to_fields=[to_field],
**kwargs,
)
self.db_constraint = db_constraint
def __class_getitem__(cls, *args, **kwargs):
return cls
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_on_delete(),
*self._check_unique(),
]
def _check_on_delete(self):
on_delete = getattr(self.remote_field, "on_delete", None)
if on_delete == SET_NULL and not self.null:
return [
checks.Error(
"Field specifies on_delete=SET_NULL, but cannot be null.",
hint=(
"Set null=True argument on the field, or change the on_delete "
"rule."
),
obj=self,
id="fields.E320",
)
]
elif on_delete == SET_DEFAULT and not self.has_default():
return [
checks.Error(
"Field specifies on_delete=SET_DEFAULT, but has no default value.",
hint="Set a default value, or change the on_delete rule.",
obj=self,
id="fields.E321",
)
]
else:
return []
def _check_unique(self, **kwargs):
return (
[
checks.Warning(
"Setting unique=True on a ForeignKey has the same effect as using "
"a OneToOneField.",
hint=(
"ForeignKey(unique=True) is usually better served by a "
"OneToOneField."
),
obj=self,
id="fields.W342",
)
]
if self.unique
else []
)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["to_fields"]
del kwargs["from_fields"]
# Handle the simpler arguments
if self.db_index:
del kwargs["db_index"]
else:
kwargs["db_index"] = False
if self.db_constraint is not True:
kwargs["db_constraint"] = self.db_constraint
# Rel needs more work.
to_meta = getattr(self.remote_field.model, "_meta", None)
if self.remote_field.field_name and (
not to_meta
or (to_meta.pk and self.remote_field.field_name != to_meta.pk.name)
):
kwargs["to_field"] = self.remote_field.field_name
return name, path, args, kwargs
def to_python(self, value):
return self.target_field.to_python(value)
@property
def target_field(self):
return self.foreign_related_fields[0]
def validate(self, value, model_instance):
if self.remote_field.parent_link:
return
super().validate(value, model_instance)
if value is None:
return
using = router.db_for_read(self.remote_field.model, instance=model_instance)
qs = self.remote_field.model._base_manager.using(using).filter(
**{self.remote_field.field_name: value}
)
qs = qs.complex_filter(self.get_limit_choices_to())
if not qs.exists():
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={
"model": self.remote_field.model._meta.verbose_name,
"pk": value,
"field": self.remote_field.field_name,
"value": value,
}, # 'pk' is included for backwards compatibility
)
def resolve_related_fields(self):
related_fields = super().resolve_related_fields()
for from_field, to_field in related_fields:
if (
to_field
and to_field.model != self.remote_field.model._meta.concrete_model
):
raise exceptions.FieldError(
"'%s.%s' refers to field '%s' which is not local to model "
"'%s'."
% (
self.model._meta.label,
self.name,
to_field.name,
self.remote_field.model._meta.concrete_model._meta.label,
)
)
return related_fields
def get_attname(self):
return "%s_id" % self.name
def get_attname_column(self):
attname = self.get_attname()
column = self.db_column or attname
return attname, column
def get_default(self):
"""Return the to_field if the default value is an object."""
field_default = super().get_default()
if isinstance(field_default, self.remote_field.model):
return getattr(field_default, self.target_field.attname)
return field_default
def get_db_prep_save(self, value, connection):
if value is None or (
value == ""
and (
not self.target_field.empty_strings_allowed
or connection.features.interprets_empty_strings_as_nulls
)
):
return None
else:
return self.target_field.get_db_prep_save(value, connection=connection)
def get_db_prep_value(self, value, connection, prepared=False):
return self.target_field.get_db_prep_value(value, connection, prepared)
def get_prep_value(self, value):
return self.target_field.get_prep_value(value)
def contribute_to_related_class(self, cls, related):
super().contribute_to_related_class(cls, related)
if self.remote_field.field_name is None:
self.remote_field.field_name = cls._meta.pk.name
def formfield(self, *, using=None, **kwargs):
if isinstance(self.remote_field.model, str):
raise ValueError(
"Cannot create form field for %r yet, because "
"its related model %r has not been loaded yet"
% (self.name, self.remote_field.model)
)
return super().formfield(
**{
"form_class": forms.ModelChoiceField,
"queryset": self.remote_field.model._default_manager.using(using),
"to_field_name": self.remote_field.field_name,
**kwargs,
"blank": self.blank,
}
)
def db_check(self, connection):
return None
def db_type(self, connection):
return self.target_field.rel_db_type(connection=connection)
def db_parameters(self, connection):
target_db_parameters = self.target_field.db_parameters(connection)
return {
"type": self.db_type(connection),
"check": self.db_check(connection),
"collation": target_db_parameters.get("collation"),
}
def convert_empty_strings(self, value, expression, connection):
if (not value) and isinstance(value, str):
return None
return value
def get_db_converters(self, connection):
converters = super().get_db_converters(connection)
if connection.features.interprets_empty_strings_as_nulls:
converters += [self.convert_empty_strings]
return converters
def get_col(self, alias, output_field=None):
if output_field is None:
output_field = self.target_field
while isinstance(output_field, ForeignKey):
output_field = output_field.target_field
if output_field is self:
raise ValueError("Cannot resolve output_field.")
return super().get_col(alias, output_field)
class OneToOneField(ForeignKey):
"""
A OneToOneField is essentially the same as a ForeignKey, with the exception
that it always carries a "unique" constraint with it and the reverse
relation always returns the object pointed to (since there will only ever
be one), rather than returning a list.
"""
# Field flags
many_to_many = False
many_to_one = False
one_to_many = False
one_to_one = True
related_accessor_class = ReverseOneToOneDescriptor
forward_related_accessor_class = ForwardOneToOneDescriptor
rel_class = OneToOneRel
description = _("One-to-one relationship")
def __init__(self, to, on_delete, to_field=None, **kwargs):
kwargs["unique"] = True
super().__init__(to, on_delete, to_field=to_field, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if "unique" in kwargs:
del kwargs["unique"]
return name, path, args, kwargs
def formfield(self, **kwargs):
if self.remote_field.parent_link:
return None
return super().formfield(**kwargs)
def save_form_data(self, instance, data):
if isinstance(data, self.remote_field.model):
setattr(instance, self.name, data)
else:
setattr(instance, self.attname, data)
# Remote field object must be cleared otherwise Model.save()
# will reassign attname using the related object pk.
if data is None:
setattr(instance, self.name, data)
def _check_unique(self, **kwargs):
# Override ForeignKey since check isn't applicable here.
return []
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = "%s_%s" % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = "to_%s" % to
from_ = "from_%s" % from_
meta = type(
"Meta",
(),
{
"db_table": field._get_m2m_db_table(klass._meta),
"auto_created": klass,
"app_label": klass._meta.app_label,
"db_tablespace": klass._meta.db_tablespace,
"unique_together": (from_, to),
"verbose_name": _("%(from)s-%(to)s relationship")
% {"from": from_, "to": to},
"verbose_name_plural": _("%(from)s-%(to)s relationships")
% {"from": from_, "to": to},
"apps": field.model._meta.apps,
},
)
# Construct and return the new class.
return type(
name,
(models.Model,),
{
"Meta": meta,
"__module__": klass.__module__,
from_: models.ForeignKey(
klass,
related_name="%s+" % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name="%s+" % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
},
)
class ManyToManyField(RelatedField):
"""
Provide a many-to-many relation by using an intermediary model that
holds two ForeignKey fields pointed at the two sides of the relation.
Unless a ``through`` model was provided, ManyToManyField will use the
create_many_to_many_intermediary_model factory to automatically generate
the intermediary model.
"""
# Field flags
many_to_many = True
many_to_one = False
one_to_many = False
one_to_one = False
rel_class = ManyToManyRel
description = _("Many-to-many relationship")
def __init__(
self,
to,
related_name=None,
related_query_name=None,
limit_choices_to=None,
symmetrical=None,
through=None,
through_fields=None,
db_constraint=True,
db_table=None,
swappable=True,
**kwargs,
):
try:
to._meta
except AttributeError:
if not isinstance(to, str):
raise TypeError(
"%s(%r) is invalid. First parameter to ManyToManyField "
"must be either a model, a model name, or the string %r"
% (
self.__class__.__name__,
to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
if symmetrical is None:
symmetrical = to == RECURSIVE_RELATIONSHIP_CONSTANT
if through is not None and db_table is not None:
raise ValueError(
"Cannot specify a db_table if an intermediary model is used."
)
kwargs["rel"] = self.rel_class(
self,
to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
symmetrical=symmetrical,
through=through,
through_fields=through_fields,
db_constraint=db_constraint,
)
self.has_null_arg = "null" in kwargs
super().__init__(
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
**kwargs,
)
self.db_table = db_table
self.swappable = swappable
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_unique(**kwargs),
*self._check_relationship_model(**kwargs),
*self._check_ignored_options(**kwargs),
*self._check_table_uniqueness(**kwargs),
]
def _check_unique(self, **kwargs):
if self.unique:
return [
checks.Error(
"ManyToManyFields cannot be unique.",
obj=self,
id="fields.E330",
)
]
return []
def _check_ignored_options(self, **kwargs):
warnings = []
if self.has_null_arg:
warnings.append(
checks.Warning(
"null has no effect on ManyToManyField.",
obj=self,
id="fields.W340",
)
)
if self._validators:
warnings.append(
checks.Warning(
"ManyToManyField does not support validators.",
obj=self,
id="fields.W341",
)
)
if self.remote_field.symmetrical and self._related_name:
warnings.append(
checks.Warning(
"related_name has no effect on ManyToManyField "
'with a symmetrical relationship, e.g. to "self".',
obj=self,
id="fields.W345",
)
)
if self.db_comment:
warnings.append(
checks.Warning(
"db_comment has no effect on ManyToManyField.",
obj=self,
id="fields.W346",
)
)
return warnings
def _check_relationship_model(self, from_model=None, **kwargs):
if hasattr(self.remote_field.through, "_meta"):
qualified_model_name = "%s.%s" % (
self.remote_field.through._meta.app_label,
self.remote_field.through.__name__,
)
else:
qualified_model_name = self.remote_field.through
errors = []
if self.remote_field.through not in self.opts.apps.get_models(
include_auto_created=True
):
# The relationship model is not installed.
errors.append(
checks.Error(
"Field specifies a many-to-many relation through model "
"'%s', which has not been installed." % qualified_model_name,
obj=self,
id="fields.E331",
)
)
else:
assert from_model is not None, (
"ManyToManyField with intermediate "
"tables cannot be checked if you don't pass the model "
"where the field is attached to."
)
# Set some useful local variables
to_model = resolve_relation(from_model, self.remote_field.model)
from_model_name = from_model._meta.object_name
if isinstance(to_model, str):
to_model_name = to_model
else:
to_model_name = to_model._meta.object_name
relationship_model_name = self.remote_field.through._meta.object_name
self_referential = from_model == to_model
# Count foreign keys in intermediate model
if self_referential:
seen_self = sum(
from_model == getattr(field.remote_field, "model", None)
for field in self.remote_field.through._meta.fields
)
if seen_self > 2 and not self.remote_field.through_fields:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it has more than two foreign keys "
"to '%s', which is ambiguous. You must specify "
"which two foreign keys Django should use via the "
"through_fields keyword argument."
% (self, from_model_name),
hint=(
"Use through_fields to specify which two foreign keys "
"Django should use."
),
obj=self.remote_field.through,
id="fields.E333",
)
)
else:
# Count foreign keys in relationship model
seen_from = sum(
from_model == getattr(field.remote_field, "model", None)
for field in self.remote_field.through._meta.fields
)
seen_to = sum(
to_model == getattr(field.remote_field, "model", None)
for field in self.remote_field.through._meta.fields
)
if seen_from > 1 and not self.remote_field.through_fields:
errors.append(
checks.Error(
(
"The model is used as an intermediate model by "
"'%s', but it has more than one foreign key "
"from '%s', which is ambiguous. You must specify "
"which foreign key Django should use via the "
"through_fields keyword argument."
)
% (self, from_model_name),
hint=(
"If you want to create a recursive relationship, "
'use ManyToManyField("%s", through="%s").'
)
% (
RECURSIVE_RELATIONSHIP_CONSTANT,
relationship_model_name,
),
obj=self,
id="fields.E334",
)
)
if seen_to > 1 and not self.remote_field.through_fields:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it has more than one foreign key "
"to '%s', which is ambiguous. You must specify "
"which foreign key Django should use via the "
"through_fields keyword argument." % (self, to_model_name),
hint=(
"If you want to create a recursive relationship, "
'use ManyToManyField("%s", through="%s").'
)
% (
RECURSIVE_RELATIONSHIP_CONSTANT,
relationship_model_name,
),
obj=self,
id="fields.E335",
)
)
if seen_from == 0 or seen_to == 0:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it does not have a foreign key to '%s' or '%s'."
% (self, from_model_name, to_model_name),
obj=self.remote_field.through,
id="fields.E336",
)
)
# Validate `through_fields`.
if self.remote_field.through_fields is not None:
# Validate that we're given an iterable of at least two items
# and that none of them is "falsy".
if not (
len(self.remote_field.through_fields) >= 2
and self.remote_field.through_fields[0]
and self.remote_field.through_fields[1]
):
errors.append(
checks.Error(
"Field specifies 'through_fields' but does not provide "
"the names of the two link fields that should be used "
"for the relation through model '%s'." % qualified_model_name,
hint=(
"Make sure you specify 'through_fields' as "
"through_fields=('field1', 'field2')"
),
obj=self,
id="fields.E337",
)
)
# Validate the given through fields -- they should be actual
# fields on the through model, and also be foreign keys to the
# expected models.
else:
assert from_model is not None, (
"ManyToManyField with intermediate "
"tables cannot be checked if you don't pass the model "
"where the field is attached to."
)
source, through, target = (
from_model,
self.remote_field.through,
self.remote_field.model,
)
source_field_name, target_field_name = self.remote_field.through_fields[
:2
]
for field_name, related_model in (
(source_field_name, source),
(target_field_name, target),
):
possible_field_names = []
for f in through._meta.fields:
if (
hasattr(f, "remote_field")
and getattr(f.remote_field, "model", None) == related_model
):
possible_field_names.append(f.name)
if possible_field_names:
hint = (
"Did you mean one of the following foreign keys to '%s': "
"%s?"
% (
related_model._meta.object_name,
", ".join(possible_field_names),
)
)
else:
hint = None
try:
field = through._meta.get_field(field_name)
except exceptions.FieldDoesNotExist:
errors.append(
checks.Error(
"The intermediary model '%s' has no field '%s'."
% (qualified_model_name, field_name),
hint=hint,
obj=self,
id="fields.E338",
)
)
else:
if not (
hasattr(field, "remote_field")
and getattr(field.remote_field, "model", None)
== related_model
):
errors.append(
checks.Error(
"'%s.%s' is not a foreign key to '%s'."
% (
through._meta.object_name,
field_name,
related_model._meta.object_name,
),
hint=hint,
obj=self,
id="fields.E339",
)
)
return errors
def _check_table_uniqueness(self, **kwargs):
if (
isinstance(self.remote_field.through, str)
or not self.remote_field.through._meta.managed
):
return []
registered_tables = {
model._meta.db_table: model
for model in self.opts.apps.get_models(include_auto_created=True)
if model != self.remote_field.through and model._meta.managed
}
m2m_db_table = self.m2m_db_table()
model = registered_tables.get(m2m_db_table)
# The second condition allows multiple m2m relations on a model if
# some point to a through model that proxies another through model.
if (
model
and model._meta.concrete_model
!= self.remote_field.through._meta.concrete_model
):
if model._meta.auto_created:
def _get_field_name(model):
for field in model._meta.auto_created._meta.many_to_many:
if field.remote_field.through is model:
return field.name
opts = model._meta.auto_created._meta
clashing_obj = "%s.%s" % (opts.label, _get_field_name(model))
else:
clashing_obj = model._meta.label
if settings.DATABASE_ROUTERS:
error_class, error_id = checks.Warning, "fields.W344"
error_hint = (
"You have configured settings.DATABASE_ROUTERS. Verify "
"that the table of %r is correctly routed to a separate "
"database." % clashing_obj
)
else:
error_class, error_id = checks.Error, "fields.E340"
error_hint = None
return [
error_class(
"The field's intermediary table '%s' clashes with the "
"table name of '%s'." % (m2m_db_table, clashing_obj),
obj=self,
hint=error_hint,
id=error_id,
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
# Handle the simpler arguments.
if self.db_table is not None:
kwargs["db_table"] = self.db_table
if self.remote_field.db_constraint is not True:
kwargs["db_constraint"] = self.remote_field.db_constraint
# Lowercase model names as they should be treated as case-insensitive.
if isinstance(self.remote_field.model, str):
if "." in self.remote_field.model:
app_label, model_name = self.remote_field.model.split(".")
kwargs["to"] = "%s.%s" % (app_label, model_name.lower())
else:
kwargs["to"] = self.remote_field.model.lower()
else:
kwargs["to"] = self.remote_field.model._meta.label_lower
if getattr(self.remote_field, "through", None) is not None:
if isinstance(self.remote_field.through, str):
kwargs["through"] = self.remote_field.through
elif not self.remote_field.through._meta.auto_created:
kwargs["through"] = self.remote_field.through._meta.label
# If swappable is True, then see if we're actually pointing to the target
# of a swap.
swappable_setting = self.swappable_setting
if swappable_setting is not None:
# If it's already a settings reference, error.
if hasattr(kwargs["to"], "setting_name"):
if kwargs["to"].setting_name != swappable_setting:
raise ValueError(
"Cannot deconstruct a ManyToManyField pointing to a "
"model that is swapped in place of more than one model "
"(%s and %s)" % (kwargs["to"].setting_name, swappable_setting)
)
kwargs["to"] = SettingsReference(
kwargs["to"],
swappable_setting,
)
return name, path, args, kwargs
def _get_path_info(self, direct=False, filtered_relation=None):
"""Called by both direct and indirect m2m traversal."""
int_model = self.remote_field.through
linkfield1 = int_model._meta.get_field(self.m2m_field_name())
linkfield2 = int_model._meta.get_field(self.m2m_reverse_field_name())
if direct:
join1infos = linkfield1.reverse_path_infos
if filtered_relation:
join2infos = linkfield2.get_path_info(filtered_relation)
else:
join2infos = linkfield2.path_infos
else:
join1infos = linkfield2.reverse_path_infos
if filtered_relation:
join2infos = linkfield1.get_path_info(filtered_relation)
else:
join2infos = linkfield1.path_infos
# Get join infos between the last model of join 1 and the first model
# of join 2. Assume the only reason these may differ is due to model
# inheritance.
join1_final = join1infos[-1].to_opts
join2_initial = join2infos[0].from_opts
if join1_final is join2_initial:
intermediate_infos = []
elif issubclass(join1_final.model, join2_initial.model):
intermediate_infos = join1_final.get_path_to_parent(join2_initial.model)
else:
intermediate_infos = join2_initial.get_path_from_parent(join1_final.model)
return [*join1infos, *intermediate_infos, *join2infos]
def get_path_info(self, filtered_relation=None):
return self._get_path_info(direct=True, filtered_relation=filtered_relation)
@cached_property
def path_infos(self):
return self.get_path_info()
def get_reverse_path_info(self, filtered_relation=None):
return self._get_path_info(direct=False, filtered_relation=filtered_relation)
@cached_property
def reverse_path_infos(self):
return self.get_reverse_path_info()
def _get_m2m_db_table(self, opts):
"""
Function that can be curried to provide the m2m table name for this
relation.
"""
if self.remote_field.through is not None:
return self.remote_field.through._meta.db_table
elif self.db_table:
return self.db_table
else:
m2m_table_name = "%s_%s" % (utils.strip_quotes(opts.db_table), self.name)
return utils.truncate_name(m2m_table_name, connection.ops.max_name_length())
def _get_m2m_attr(self, related, attr):
"""
Function that can be curried to provide the source accessor or DB
column name for the m2m table.
"""
cache_attr = "_m2m_%s_cache" % attr
if hasattr(self, cache_attr):
return getattr(self, cache_attr)
if self.remote_field.through_fields is not None:
link_field_name = self.remote_field.through_fields[0]
else:
link_field_name = None
for f in self.remote_field.through._meta.fields:
if (
f.is_relation
and f.remote_field.model == related.related_model
and (link_field_name is None or link_field_name == f.name)
):
setattr(self, cache_attr, getattr(f, attr))
return getattr(self, cache_attr)
def _get_m2m_reverse_attr(self, related, attr):
"""
Function that can be curried to provide the related accessor or DB
column name for the m2m table.
"""
cache_attr = "_m2m_reverse_%s_cache" % attr
if hasattr(self, cache_attr):
return getattr(self, cache_attr)
found = False
if self.remote_field.through_fields is not None:
link_field_name = self.remote_field.through_fields[1]
else:
link_field_name = None
for f in self.remote_field.through._meta.fields:
if f.is_relation and f.remote_field.model == related.model:
if link_field_name is None and related.related_model == related.model:
# If this is an m2m-intermediate to self,
# the first foreign key you find will be
# the source column. Keep searching for
# the second foreign key.
if found:
setattr(self, cache_attr, getattr(f, attr))
break
else:
found = True
elif link_field_name is None or link_field_name == f.name:
setattr(self, cache_attr, getattr(f, attr))
break
return getattr(self, cache_attr)
def contribute_to_class(self, cls, name, **kwargs):
# To support multiple relations to self, it's useful to have a non-None
# related name on symmetrical relations for internal reasons. The
# concept doesn't make a lot of sense externally ("you want me to
# specify *what* on my non-reversible relation?!"), so we set it up
# automatically. The funky name reduces the chance of an accidental
# clash.
if self.remote_field.symmetrical and (
self.remote_field.model == RECURSIVE_RELATIONSHIP_CONSTANT
or self.remote_field.model == cls._meta.object_name
):
self.remote_field.related_name = "%s_rel_+" % name
elif self.remote_field.is_hidden():
# If the backwards relation is disabled, replace the original
# related_name with one generated from the m2m field name. Django
# still uses backwards relations internally and we need to avoid
# clashes between multiple m2m fields with related_name == '+'.
self.remote_field.related_name = "_%s_%s_%s_+" % (
cls._meta.app_label,
cls.__name__.lower(),
name,
)
super().contribute_to_class(cls, name, **kwargs)
# The intermediate m2m model is not auto created if:
# 1) There is a manually specified intermediate, or
# 2) The class owning the m2m field is abstract.
# 3) The class owning the m2m field has been swapped out.
if not cls._meta.abstract:
if self.remote_field.through:
def resolve_through_model(_, model, field):
field.remote_field.through = model
lazy_related_operation(
resolve_through_model, cls, self.remote_field.through, field=self
)
elif not cls._meta.swapped:
self.remote_field.through = create_many_to_many_intermediary_model(
self, cls
)
# Add the descriptor for the m2m relation.
setattr(cls, self.name, ManyToManyDescriptor(self.remote_field, reverse=False))
# Set up the accessor for the m2m table name for the relation.
self.m2m_db_table = partial(self._get_m2m_db_table, cls._meta)
def contribute_to_related_class(self, cls, related):
# Internal M2Ms (i.e., those with a related name ending with '+')
# and swapped models don't get a related descriptor.
if (
not self.remote_field.is_hidden()
and not related.related_model._meta.swapped
):
setattr(
cls,
related.get_accessor_name(),
ManyToManyDescriptor(self.remote_field, reverse=True),
)
# Set up the accessors for the column names on the m2m table.
self.m2m_column_name = partial(self._get_m2m_attr, related, "column")
self.m2m_reverse_name = partial(self._get_m2m_reverse_attr, related, "column")
self.m2m_field_name = partial(self._get_m2m_attr, related, "name")
self.m2m_reverse_field_name = partial(
self._get_m2m_reverse_attr, related, "name"
)
get_m2m_rel = partial(self._get_m2m_attr, related, "remote_field")
self.m2m_target_field_name = lambda: get_m2m_rel().field_name
get_m2m_reverse_rel = partial(
self._get_m2m_reverse_attr, related, "remote_field"
)
self.m2m_reverse_target_field_name = lambda: get_m2m_reverse_rel().field_name
def set_attributes_from_rel(self):
pass
def value_from_object(self, obj):
return [] if obj.pk is None else list(getattr(obj, self.attname).all())
def save_form_data(self, instance, data):
getattr(instance, self.attname).set(data)
def formfield(self, *, using=None, **kwargs):
defaults = {
"form_class": forms.ModelMultipleChoiceField,
"queryset": self.remote_field.model._default_manager.using(using),
**kwargs,
}
# If initial is passed in, it's a list of related objects, but the
# MultipleChoiceField takes a list of IDs.
if defaults.get("initial") is not None:
initial = defaults["initial"]
if callable(initial):
initial = initial()
defaults["initial"] = [i.pk for i in initial]
return super().formfield(**defaults)
def db_check(self, connection):
return None
def db_type(self, connection):
# A ManyToManyField is not represented by a single column,
# so return None.
return None
def db_parameters(self, connection):
return {"type": None, "check": None}
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/related.py
|
Python
|
mit
| 75,796 |
"""
Accessors for related objects.
When a field defines a relation between two models, each model class provides
an attribute to access related instances of the other model class (unless the
reverse accessor has been disabled with related_name='+').
Accessors are implemented as descriptors in order to customize access and
assignment. This module defines the descriptor classes.
Forward accessors follow foreign keys. Reverse accessors trace them back. For
example, with the following models::
class Parent(Model):
pass
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``child.parent`` is a forward many-to-one relation. ``parent.children`` is a
reverse many-to-one relation.
There are three types of relations (many-to-one, one-to-one, and many-to-many)
and two directions (forward and reverse) for a total of six combinations.
1. Related instance on the forward side of a many-to-one relation:
``ForwardManyToOneDescriptor``.
Uniqueness of foreign key values is irrelevant to accessing the related
instance, making the many-to-one and one-to-one cases identical as far as
the descriptor is concerned. The constraint is checked upstream (unicity
validation in forms) or downstream (unique indexes in the database).
2. Related instance on the forward side of a one-to-one
relation: ``ForwardOneToOneDescriptor``.
It avoids querying the database when accessing the parent link field in
a multi-table inheritance scenario.
3. Related instance on the reverse side of a one-to-one relation:
``ReverseOneToOneDescriptor``.
One-to-one relations are asymmetrical, despite the apparent symmetry of the
name, because they're implemented in the database with a foreign key from
one table to another. As a consequence ``ReverseOneToOneDescriptor`` is
slightly different from ``ForwardManyToOneDescriptor``.
4. Related objects manager for related instances on the reverse side of a
many-to-one relation: ``ReverseManyToOneDescriptor``.
Unlike the previous two classes, this one provides access to a collection
of objects. It returns a manager rather than an instance.
5. Related objects manager for related instances on the forward or reverse
sides of a many-to-many relation: ``ManyToManyDescriptor``.
Many-to-many relations are symmetrical. The syntax of Django models
requires declaring them on one side but that's an implementation detail.
They could be declared on the other side without any change in behavior.
Therefore the forward and reverse descriptors can be the same.
If you're looking for ``ForwardManyToManyDescriptor`` or
``ReverseManyToManyDescriptor``, use ``ManyToManyDescriptor`` instead.
"""
from asgiref.sync import sync_to_async
from django.core.exceptions import FieldError
from django.db import (
DEFAULT_DB_ALIAS,
NotSupportedError,
connections,
router,
transaction,
)
from django.db.models import Q, Window, signals
from django.db.models.functions import RowNumber
from django.db.models.lookups import GreaterThan, LessThanOrEqual
from django.db.models.query import QuerySet
from django.db.models.query_utils import DeferredAttribute
from django.db.models.utils import AltersData, resolve_callables
from django.utils.functional import cached_property
class ForeignKeyDeferredAttribute(DeferredAttribute):
def __set__(self, instance, value):
if instance.__dict__.get(self.field.attname) != value and self.field.is_cached(
instance
):
self.field.delete_cached_value(instance)
instance.__dict__[self.field.attname] = value
def _filter_prefetch_queryset(queryset, field_name, instances):
predicate = Q(**{f"{field_name}__in": instances})
db = queryset._db or DEFAULT_DB_ALIAS
if queryset.query.is_sliced:
if not connections[db].features.supports_over_clause:
raise NotSupportedError(
"Prefetching from a limited queryset is only supported on backends "
"that support window functions."
)
low_mark, high_mark = queryset.query.low_mark, queryset.query.high_mark
order_by = [
expr for expr, _ in queryset.query.get_compiler(using=db).get_order_by()
]
window = Window(RowNumber(), partition_by=field_name, order_by=order_by)
predicate &= GreaterThan(window, low_mark)
if high_mark is not None:
predicate &= LessThanOrEqual(window, high_mark)
queryset.query.clear_limits()
return queryset.filter(predicate)
class ForwardManyToOneDescriptor:
"""
Accessor to the related object on the forward side of a many-to-one or
one-to-one (via ForwardOneToOneDescriptor subclass) relation.
In the example::
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``Child.parent`` is a ``ForwardManyToOneDescriptor`` instance.
"""
def __init__(self, field_with_rel):
self.field = field_with_rel
@cached_property
def RelatedObjectDoesNotExist(self):
# The exception can't be created at initialization time since the
# related model might not be resolved yet; `self.field.model` might
# still be a string model reference.
return type(
"RelatedObjectDoesNotExist",
(self.field.remote_field.model.DoesNotExist, AttributeError),
{
"__module__": self.field.model.__module__,
"__qualname__": "%s.%s.RelatedObjectDoesNotExist"
% (
self.field.model.__qualname__,
self.field.name,
),
},
)
def is_cached(self, instance):
return self.field.is_cached(instance)
def get_queryset(self, **hints):
return self.field.remote_field.model._base_manager.db_manager(hints=hints).all()
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = self.get_queryset()
queryset._add_hints(instance=instances[0])
rel_obj_attr = self.field.get_foreign_related_value
instance_attr = self.field.get_local_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
related_field = self.field.foreign_related_fields[0]
remote_field = self.field.remote_field
# FIXME: This will need to be revisited when we introduce support for
# composite fields. In the meantime we take this practical approach to
# solve a regression on 1.6 when the reverse manager in hidden
# (related_name ends with a '+'). Refs #21410.
# The check for len(...) == 1 is a special case that allows the query
# to be join-less and smaller. Refs #21760.
if remote_field.is_hidden() or len(self.field.foreign_related_fields) == 1:
query = {
"%s__in"
% related_field.name: {instance_attr(inst)[0] for inst in instances}
}
else:
query = {"%s__in" % self.field.related_query_name(): instances}
queryset = queryset.filter(**query)
# Since we're going to assign directly in the cache,
# we must manage the reverse relation cache manually.
if not remote_field.multiple:
for rel_obj in queryset:
instance = instances_dict[rel_obj_attr(rel_obj)]
remote_field.set_cached_value(rel_obj, instance)
return (
queryset,
rel_obj_attr,
instance_attr,
True,
self.field.get_cache_name(),
False,
)
def get_object(self, instance):
qs = self.get_queryset(instance=instance)
# Assuming the database enforces foreign keys, this won't fail.
return qs.get(self.field.get_reverse_related_filter(instance))
def __get__(self, instance, cls=None):
"""
Get the related instance through the forward relation.
With the example above, when getting ``child.parent``:
- ``self`` is the descriptor managing the ``parent`` attribute
- ``instance`` is the ``child`` instance
- ``cls`` is the ``Child`` class (we don't need it)
"""
if instance is None:
return self
# The related instance is loaded from the database and then cached
# by the field on the model instance state. It can also be pre-cached
# by the reverse accessor (ReverseOneToOneDescriptor).
try:
rel_obj = self.field.get_cached_value(instance)
except KeyError:
has_value = None not in self.field.get_local_related_value(instance)
ancestor_link = (
instance._meta.get_ancestor_link(self.field.model)
if has_value
else None
)
if ancestor_link and ancestor_link.is_cached(instance):
# An ancestor link will exist if this field is defined on a
# multi-table inheritance parent of the instance's class.
ancestor = ancestor_link.get_cached_value(instance)
# The value might be cached on an ancestor if the instance
# originated from walking down the inheritance chain.
rel_obj = self.field.get_cached_value(ancestor, default=None)
else:
rel_obj = None
if rel_obj is None and has_value:
rel_obj = self.get_object(instance)
remote_field = self.field.remote_field
# If this is a one-to-one relation, set the reverse accessor
# cache on the related object to the current instance to avoid
# an extra SQL query if it's accessed later on.
if not remote_field.multiple:
remote_field.set_cached_value(rel_obj, instance)
self.field.set_cached_value(instance, rel_obj)
if rel_obj is None and not self.field.null:
raise self.RelatedObjectDoesNotExist(
"%s has no %s." % (self.field.model.__name__, self.field.name)
)
else:
return rel_obj
def __set__(self, instance, value):
"""
Set the related instance through the forward relation.
With the example above, when setting ``child.parent = parent``:
- ``self`` is the descriptor managing the ``parent`` attribute
- ``instance`` is the ``child`` instance
- ``value`` is the ``parent`` instance on the right of the equal sign
"""
# An object must be an instance of the related class.
if value is not None and not isinstance(
value, self.field.remote_field.model._meta.concrete_model
):
raise ValueError(
'Cannot assign "%r": "%s.%s" must be a "%s" instance.'
% (
value,
instance._meta.object_name,
self.field.name,
self.field.remote_field.model._meta.object_name,
)
)
elif value is not None:
if instance._state.db is None:
instance._state.db = router.db_for_write(
instance.__class__, instance=value
)
if value._state.db is None:
value._state.db = router.db_for_write(
value.__class__, instance=instance
)
if not router.allow_relation(value, instance):
raise ValueError(
'Cannot assign "%r": the current database router prevents this '
"relation." % value
)
remote_field = self.field.remote_field
# If we're setting the value of a OneToOneField to None, we need to clear
# out the cache on any old related object. Otherwise, deleting the
# previously-related object will also cause this object to be deleted,
# which is wrong.
if value is None:
# Look up the previously-related object, which may still be available
# since we've not yet cleared out the related field.
# Use the cache directly, instead of the accessor; if we haven't
# populated the cache, then we don't care - we're only accessing
# the object to invalidate the accessor cache, so there's no
# need to populate the cache just to expire it again.
related = self.field.get_cached_value(instance, default=None)
# If we've got an old related object, we need to clear out its
# cache. This cache also might not exist if the related object
# hasn't been accessed yet.
if related is not None:
remote_field.set_cached_value(related, None)
for lh_field, rh_field in self.field.related_fields:
setattr(instance, lh_field.attname, None)
# Set the values of the related field.
else:
for lh_field, rh_field in self.field.related_fields:
setattr(instance, lh_field.attname, getattr(value, rh_field.attname))
# Set the related instance cache used by __get__ to avoid an SQL query
# when accessing the attribute we just set.
self.field.set_cached_value(instance, value)
# If this is a one-to-one relation, set the reverse accessor cache on
# the related object to the current instance to avoid an extra SQL
# query if it's accessed later on.
if value is not None and not remote_field.multiple:
remote_field.set_cached_value(value, instance)
def __reduce__(self):
"""
Pickling should return the instance attached by self.field on the
model, not a new copy of that descriptor. Use getattr() to retrieve
the instance directly from the model.
"""
return getattr, (self.field.model, self.field.name)
class ForwardOneToOneDescriptor(ForwardManyToOneDescriptor):
"""
Accessor to the related object on the forward side of a one-to-one relation.
In the example::
class Restaurant(Model):
place = OneToOneField(Place, related_name='restaurant')
``Restaurant.place`` is a ``ForwardOneToOneDescriptor`` instance.
"""
def get_object(self, instance):
if self.field.remote_field.parent_link:
deferred = instance.get_deferred_fields()
# Because it's a parent link, all the data is available in the
# instance, so populate the parent model with this data.
rel_model = self.field.remote_field.model
fields = [field.attname for field in rel_model._meta.concrete_fields]
# If any of the related model's fields are deferred, fallback to
# fetching all fields from the related model. This avoids a query
# on the related model for every deferred field.
if not any(field in fields for field in deferred):
kwargs = {field: getattr(instance, field) for field in fields}
obj = rel_model(**kwargs)
obj._state.adding = instance._state.adding
obj._state.db = instance._state.db
return obj
return super().get_object(instance)
def __set__(self, instance, value):
super().__set__(instance, value)
# If the primary key is a link to a parent model and a parent instance
# is being set, update the value of the inherited pk(s).
if self.field.primary_key and self.field.remote_field.parent_link:
opts = instance._meta
# Inherited primary key fields from this object's base classes.
inherited_pk_fields = [
field
for field in opts.concrete_fields
if field.primary_key and field.remote_field
]
for field in inherited_pk_fields:
rel_model_pk_name = field.remote_field.model._meta.pk.attname
raw_value = (
getattr(value, rel_model_pk_name) if value is not None else None
)
setattr(instance, rel_model_pk_name, raw_value)
class ReverseOneToOneDescriptor:
"""
Accessor to the related object on the reverse side of a one-to-one
relation.
In the example::
class Restaurant(Model):
place = OneToOneField(Place, related_name='restaurant')
``Place.restaurant`` is a ``ReverseOneToOneDescriptor`` instance.
"""
def __init__(self, related):
# Following the example above, `related` is an instance of OneToOneRel
# which represents the reverse restaurant field (place.restaurant).
self.related = related
@cached_property
def RelatedObjectDoesNotExist(self):
# The exception isn't created at initialization time for the sake of
# consistency with `ForwardManyToOneDescriptor`.
return type(
"RelatedObjectDoesNotExist",
(self.related.related_model.DoesNotExist, AttributeError),
{
"__module__": self.related.model.__module__,
"__qualname__": "%s.%s.RelatedObjectDoesNotExist"
% (
self.related.model.__qualname__,
self.related.name,
),
},
)
def is_cached(self, instance):
return self.related.is_cached(instance)
def get_queryset(self, **hints):
return self.related.related_model._base_manager.db_manager(hints=hints).all()
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = self.get_queryset()
queryset._add_hints(instance=instances[0])
rel_obj_attr = self.related.field.get_local_related_value
instance_attr = self.related.field.get_foreign_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
query = {"%s__in" % self.related.field.name: instances}
queryset = queryset.filter(**query)
# Since we're going to assign directly in the cache,
# we must manage the reverse relation cache manually.
for rel_obj in queryset:
instance = instances_dict[rel_obj_attr(rel_obj)]
self.related.field.set_cached_value(rel_obj, instance)
return (
queryset,
rel_obj_attr,
instance_attr,
True,
self.related.get_cache_name(),
False,
)
def __get__(self, instance, cls=None):
"""
Get the related instance through the reverse relation.
With the example above, when getting ``place.restaurant``:
- ``self`` is the descriptor managing the ``restaurant`` attribute
- ``instance`` is the ``place`` instance
- ``cls`` is the ``Place`` class (unused)
Keep in mind that ``Restaurant`` holds the foreign key to ``Place``.
"""
if instance is None:
return self
# The related instance is loaded from the database and then cached
# by the field on the model instance state. It can also be pre-cached
# by the forward accessor (ForwardManyToOneDescriptor).
try:
rel_obj = self.related.get_cached_value(instance)
except KeyError:
related_pk = instance.pk
if related_pk is None:
rel_obj = None
else:
filter_args = self.related.field.get_forward_related_filter(instance)
try:
rel_obj = self.get_queryset(instance=instance).get(**filter_args)
except self.related.related_model.DoesNotExist:
rel_obj = None
else:
# Set the forward accessor cache on the related object to
# the current instance to avoid an extra SQL query if it's
# accessed later on.
self.related.field.set_cached_value(rel_obj, instance)
self.related.set_cached_value(instance, rel_obj)
if rel_obj is None:
raise self.RelatedObjectDoesNotExist(
"%s has no %s."
% (instance.__class__.__name__, self.related.get_accessor_name())
)
else:
return rel_obj
def __set__(self, instance, value):
"""
Set the related instance through the reverse relation.
With the example above, when setting ``place.restaurant = restaurant``:
- ``self`` is the descriptor managing the ``restaurant`` attribute
- ``instance`` is the ``place`` instance
- ``value`` is the ``restaurant`` instance on the right of the equal sign
Keep in mind that ``Restaurant`` holds the foreign key to ``Place``.
"""
# The similarity of the code below to the code in
# ForwardManyToOneDescriptor is annoying, but there's a bunch
# of small differences that would make a common base class convoluted.
if value is None:
# Update the cached related instance (if any) & clear the cache.
# Following the example above, this would be the cached
# ``restaurant`` instance (if any).
rel_obj = self.related.get_cached_value(instance, default=None)
if rel_obj is not None:
# Remove the ``restaurant`` instance from the ``place``
# instance cache.
self.related.delete_cached_value(instance)
# Set the ``place`` field on the ``restaurant``
# instance to None.
setattr(rel_obj, self.related.field.name, None)
elif not isinstance(value, self.related.related_model):
# An object must be an instance of the related class.
raise ValueError(
'Cannot assign "%r": "%s.%s" must be a "%s" instance.'
% (
value,
instance._meta.object_name,
self.related.get_accessor_name(),
self.related.related_model._meta.object_name,
)
)
else:
if instance._state.db is None:
instance._state.db = router.db_for_write(
instance.__class__, instance=value
)
if value._state.db is None:
value._state.db = router.db_for_write(
value.__class__, instance=instance
)
if not router.allow_relation(value, instance):
raise ValueError(
'Cannot assign "%r": the current database router prevents this '
"relation." % value
)
related_pk = tuple(
getattr(instance, field.attname)
for field in self.related.field.foreign_related_fields
)
# Set the value of the related field to the value of the related
# object's related field.
for index, field in enumerate(self.related.field.local_related_fields):
setattr(value, field.attname, related_pk[index])
# Set the related instance cache used by __get__ to avoid an SQL query
# when accessing the attribute we just set.
self.related.set_cached_value(instance, value)
# Set the forward accessor cache on the related object to the current
# instance to avoid an extra SQL query if it's accessed later on.
self.related.field.set_cached_value(value, instance)
def __reduce__(self):
# Same purpose as ForwardManyToOneDescriptor.__reduce__().
return getattr, (self.related.model, self.related.name)
class ReverseManyToOneDescriptor:
"""
Accessor to the related objects manager on the reverse side of a
many-to-one relation.
In the example::
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``Parent.children`` is a ``ReverseManyToOneDescriptor`` instance.
Most of the implementation is delegated to a dynamically defined manager
class built by ``create_forward_many_to_many_manager()`` defined below.
"""
def __init__(self, rel):
self.rel = rel
self.field = rel.field
@cached_property
def related_manager_cls(self):
related_model = self.rel.related_model
return create_reverse_many_to_one_manager(
related_model._default_manager.__class__,
self.rel,
)
def __get__(self, instance, cls=None):
"""
Get the related objects through the reverse relation.
With the example above, when getting ``parent.children``:
- ``self`` is the descriptor managing the ``children`` attribute
- ``instance`` is the ``parent`` instance
- ``cls`` is the ``Parent`` class (unused)
"""
if instance is None:
return self
return self.related_manager_cls(instance)
def _get_set_deprecation_msg_params(self):
return (
"reverse side of a related set",
self.rel.get_accessor_name(),
)
def __set__(self, instance, value):
raise TypeError(
"Direct assignment to the %s is prohibited. Use %s.set() instead."
% self._get_set_deprecation_msg_params(),
)
def create_reverse_many_to_one_manager(superclass, rel):
"""
Create a manager for the reverse side of a many-to-one relation.
This manager subclasses another manager, generally the default manager of
the related model, and adds behaviors specific to many-to-one relations.
"""
class RelatedManager(superclass, AltersData):
def __init__(self, instance):
super().__init__()
self.instance = instance
self.model = rel.related_model
self.field = rel.field
self.core_filters = {self.field.name: instance}
def __call__(self, *, manager):
manager = getattr(self.model, manager)
manager_class = create_reverse_many_to_one_manager(manager.__class__, rel)
return manager_class(self.instance)
do_not_call_in_templates = True
def _check_fk_val(self):
for field in self.field.foreign_related_fields:
if getattr(self.instance, field.attname) is None:
raise ValueError(
f'"{self.instance!r}" needs to have a value for field '
f'"{field.attname}" before this relationship can be used.'
)
def _apply_rel_filters(self, queryset):
"""
Filter the queryset for the instance this manager is bound to.
"""
db = self._db or router.db_for_read(self.model, instance=self.instance)
empty_strings_as_null = connections[
db
].features.interprets_empty_strings_as_nulls
queryset._add_hints(instance=self.instance)
if self._db:
queryset = queryset.using(self._db)
queryset._defer_next_filter = True
queryset = queryset.filter(**self.core_filters)
for field in self.field.foreign_related_fields:
val = getattr(self.instance, field.attname)
if val is None or (val == "" and empty_strings_as_null):
return queryset.none()
if self.field.many_to_one:
# Guard against field-like objects such as GenericRelation
# that abuse create_reverse_many_to_one_manager() with reverse
# one-to-many relationships instead and break known related
# objects assignment.
try:
target_field = self.field.target_field
except FieldError:
# The relationship has multiple target fields. Use a tuple
# for related object id.
rel_obj_id = tuple(
[
getattr(self.instance, target_field.attname)
for target_field in self.field.path_infos[-1].target_fields
]
)
else:
rel_obj_id = getattr(self.instance, target_field.attname)
queryset._known_related_objects = {
self.field: {rel_obj_id: self.instance}
}
return queryset
def _remove_prefetched_objects(self):
try:
self.instance._prefetched_objects_cache.pop(
self.field.remote_field.get_cache_name()
)
except (AttributeError, KeyError):
pass # nothing to clear from cache
def get_queryset(self):
# Even if this relation is not to pk, we require still pk value.
# The wish is that the instance has been already saved to DB,
# although having a pk value isn't a guarantee of that.
if self.instance.pk is None:
raise ValueError(
f"{self.instance.__class__.__name__!r} instance needs to have a "
f"primary key value before this relationship can be used."
)
try:
return self.instance._prefetched_objects_cache[
self.field.remote_field.get_cache_name()
]
except (AttributeError, KeyError):
queryset = super().get_queryset()
return self._apply_rel_filters(queryset)
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = super().get_queryset()
queryset._add_hints(instance=instances[0])
queryset = queryset.using(queryset._db or self._db)
rel_obj_attr = self.field.get_local_related_value
instance_attr = self.field.get_foreign_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
queryset = _filter_prefetch_queryset(queryset, self.field.name, instances)
# Since we just bypassed this class' get_queryset(), we must manage
# the reverse relation manually.
for rel_obj in queryset:
if not self.field.is_cached(rel_obj):
instance = instances_dict[rel_obj_attr(rel_obj)]
setattr(rel_obj, self.field.name, instance)
cache_name = self.field.remote_field.get_cache_name()
return queryset, rel_obj_attr, instance_attr, False, cache_name, False
def add(self, *objs, bulk=True):
self._check_fk_val()
self._remove_prefetched_objects()
db = router.db_for_write(self.model, instance=self.instance)
def check_and_update_obj(obj):
if not isinstance(obj, self.model):
raise TypeError(
"'%s' instance expected, got %r"
% (
self.model._meta.object_name,
obj,
)
)
setattr(obj, self.field.name, self.instance)
if bulk:
pks = []
for obj in objs:
check_and_update_obj(obj)
if obj._state.adding or obj._state.db != db:
raise ValueError(
"%r instance isn't saved. Use bulk=False or save "
"the object first." % obj
)
pks.append(obj.pk)
self.model._base_manager.using(db).filter(pk__in=pks).update(
**{
self.field.name: self.instance,
}
)
else:
with transaction.atomic(using=db, savepoint=False):
for obj in objs:
check_and_update_obj(obj)
obj.save()
add.alters_data = True
async def aadd(self, *objs, bulk=True):
return await sync_to_async(self.add)(*objs, bulk=bulk)
aadd.alters_data = True
def create(self, **kwargs):
self._check_fk_val()
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).create(**kwargs)
create.alters_data = True
async def acreate(self, **kwargs):
return await sync_to_async(self.create)(**kwargs)
acreate.alters_data = True
def get_or_create(self, **kwargs):
self._check_fk_val()
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).get_or_create(**kwargs)
get_or_create.alters_data = True
async def aget_or_create(self, **kwargs):
return await sync_to_async(self.get_or_create)(**kwargs)
aget_or_create.alters_data = True
def update_or_create(self, **kwargs):
self._check_fk_val()
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).update_or_create(**kwargs)
update_or_create.alters_data = True
async def aupdate_or_create(self, **kwargs):
return await sync_to_async(self.update_or_create)(**kwargs)
aupdate_or_create.alters_data = True
# remove() and clear() are only provided if the ForeignKey can have a
# value of null.
if rel.field.null:
def remove(self, *objs, bulk=True):
if not objs:
return
self._check_fk_val()
val = self.field.get_foreign_related_value(self.instance)
old_ids = set()
for obj in objs:
if not isinstance(obj, self.model):
raise TypeError(
"'%s' instance expected, got %r"
% (
self.model._meta.object_name,
obj,
)
)
# Is obj actually part of this descriptor set?
if self.field.get_local_related_value(obj) == val:
old_ids.add(obj.pk)
else:
raise self.field.remote_field.model.DoesNotExist(
"%r is not related to %r." % (obj, self.instance)
)
self._clear(self.filter(pk__in=old_ids), bulk)
remove.alters_data = True
async def aremove(self, *objs, bulk=True):
return await sync_to_async(self.remove)(*objs, bulk=bulk)
aremove.alters_data = True
def clear(self, *, bulk=True):
self._check_fk_val()
self._clear(self, bulk)
clear.alters_data = True
async def aclear(self, *, bulk=True):
return await sync_to_async(self.clear)(bulk=bulk)
aclear.alters_data = True
def _clear(self, queryset, bulk):
self._remove_prefetched_objects()
db = router.db_for_write(self.model, instance=self.instance)
queryset = queryset.using(db)
if bulk:
# `QuerySet.update()` is intrinsically atomic.
queryset.update(**{self.field.name: None})
else:
with transaction.atomic(using=db, savepoint=False):
for obj in queryset:
setattr(obj, self.field.name, None)
obj.save(update_fields=[self.field.name])
_clear.alters_data = True
def set(self, objs, *, bulk=True, clear=False):
self._check_fk_val()
# Force evaluation of `objs` in case it's a queryset whose value
# could be affected by `manager.clear()`. Refs #19816.
objs = tuple(objs)
if self.field.null:
db = router.db_for_write(self.model, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
if clear:
self.clear(bulk=bulk)
self.add(*objs, bulk=bulk)
else:
old_objs = set(self.using(db).all())
new_objs = []
for obj in objs:
if obj in old_objs:
old_objs.remove(obj)
else:
new_objs.append(obj)
self.remove(*old_objs, bulk=bulk)
self.add(*new_objs, bulk=bulk)
else:
self.add(*objs, bulk=bulk)
set.alters_data = True
async def aset(self, objs, *, bulk=True, clear=False):
return await sync_to_async(self.set)(objs=objs, bulk=bulk, clear=clear)
aset.alters_data = True
return RelatedManager
class ManyToManyDescriptor(ReverseManyToOneDescriptor):
"""
Accessor to the related objects manager on the forward and reverse sides of
a many-to-many relation.
In the example::
class Pizza(Model):
toppings = ManyToManyField(Topping, related_name='pizzas')
``Pizza.toppings`` and ``Topping.pizzas`` are ``ManyToManyDescriptor``
instances.
Most of the implementation is delegated to a dynamically defined manager
class built by ``create_forward_many_to_many_manager()`` defined below.
"""
def __init__(self, rel, reverse=False):
super().__init__(rel)
self.reverse = reverse
@property
def through(self):
# through is provided so that you have easy access to the through
# model (Book.authors.through) for inlines, etc. This is done as
# a property to ensure that the fully resolved value is returned.
return self.rel.through
@cached_property
def related_manager_cls(self):
related_model = self.rel.related_model if self.reverse else self.rel.model
return create_forward_many_to_many_manager(
related_model._default_manager.__class__,
self.rel,
reverse=self.reverse,
)
def _get_set_deprecation_msg_params(self):
return (
"%s side of a many-to-many set"
% ("reverse" if self.reverse else "forward"),
self.rel.get_accessor_name() if self.reverse else self.field.name,
)
def create_forward_many_to_many_manager(superclass, rel, reverse):
"""
Create a manager for the either side of a many-to-many relation.
This manager subclasses another manager, generally the default manager of
the related model, and adds behaviors specific to many-to-many relations.
"""
class ManyRelatedManager(superclass, AltersData):
def __init__(self, instance=None):
super().__init__()
self.instance = instance
if not reverse:
self.model = rel.model
self.query_field_name = rel.field.related_query_name()
self.prefetch_cache_name = rel.field.name
self.source_field_name = rel.field.m2m_field_name()
self.target_field_name = rel.field.m2m_reverse_field_name()
self.symmetrical = rel.symmetrical
else:
self.model = rel.related_model
self.query_field_name = rel.field.name
self.prefetch_cache_name = rel.field.related_query_name()
self.source_field_name = rel.field.m2m_reverse_field_name()
self.target_field_name = rel.field.m2m_field_name()
self.symmetrical = False
self.through = rel.through
self.reverse = reverse
self.source_field = self.through._meta.get_field(self.source_field_name)
self.target_field = self.through._meta.get_field(self.target_field_name)
self.core_filters = {}
self.pk_field_names = {}
for lh_field, rh_field in self.source_field.related_fields:
core_filter_key = "%s__%s" % (self.query_field_name, rh_field.name)
self.core_filters[core_filter_key] = getattr(instance, rh_field.attname)
self.pk_field_names[lh_field.name] = rh_field.name
self.related_val = self.source_field.get_foreign_related_value(instance)
if None in self.related_val:
raise ValueError(
'"%r" needs to have a value for field "%s" before '
"this many-to-many relationship can be used."
% (instance, self.pk_field_names[self.source_field_name])
)
# Even if this relation is not to pk, we require still pk value.
# The wish is that the instance has been already saved to DB,
# although having a pk value isn't a guarantee of that.
if instance.pk is None:
raise ValueError(
"%r instance needs to have a primary key value before "
"a many-to-many relationship can be used."
% instance.__class__.__name__
)
def __call__(self, *, manager):
manager = getattr(self.model, manager)
manager_class = create_forward_many_to_many_manager(
manager.__class__, rel, reverse
)
return manager_class(instance=self.instance)
do_not_call_in_templates = True
def _build_remove_filters(self, removed_vals):
filters = Q.create([(self.source_field_name, self.related_val)])
# No need to add a subquery condition if removed_vals is a QuerySet without
# filters.
removed_vals_filters = (
not isinstance(removed_vals, QuerySet) or removed_vals._has_filters()
)
if removed_vals_filters:
filters &= Q.create([(f"{self.target_field_name}__in", removed_vals)])
if self.symmetrical:
symmetrical_filters = Q.create(
[(self.target_field_name, self.related_val)]
)
if removed_vals_filters:
symmetrical_filters &= Q.create(
[(f"{self.source_field_name}__in", removed_vals)]
)
filters |= symmetrical_filters
return filters
def _apply_rel_filters(self, queryset):
"""
Filter the queryset for the instance this manager is bound to.
"""
queryset._add_hints(instance=self.instance)
if self._db:
queryset = queryset.using(self._db)
queryset._defer_next_filter = True
return queryset._next_is_sticky().filter(**self.core_filters)
def _remove_prefetched_objects(self):
try:
self.instance._prefetched_objects_cache.pop(self.prefetch_cache_name)
except (AttributeError, KeyError):
pass # nothing to clear from cache
def get_queryset(self):
try:
return self.instance._prefetched_objects_cache[self.prefetch_cache_name]
except (AttributeError, KeyError):
queryset = super().get_queryset()
return self._apply_rel_filters(queryset)
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = super().get_queryset()
queryset._add_hints(instance=instances[0])
queryset = queryset.using(queryset._db or self._db)
queryset = _filter_prefetch_queryset(
queryset._next_is_sticky(), self.query_field_name, instances
)
# M2M: need to annotate the query in order to get the primary model
# that the secondary model was actually related to. We know that
# there will already be a join on the join table, so we can just add
# the select.
# For non-autocreated 'through' models, can't assume we are
# dealing with PK values.
fk = self.through._meta.get_field(self.source_field_name)
join_table = fk.model._meta.db_table
connection = connections[queryset.db]
qn = connection.ops.quote_name
queryset = queryset.extra(
select={
"_prefetch_related_val_%s"
% f.attname: "%s.%s"
% (qn(join_table), qn(f.column))
for f in fk.local_related_fields
}
)
return (
queryset,
lambda result: tuple(
getattr(result, "_prefetch_related_val_%s" % f.attname)
for f in fk.local_related_fields
),
lambda inst: tuple(
f.get_db_prep_value(getattr(inst, f.attname), connection)
for f in fk.foreign_related_fields
),
False,
self.prefetch_cache_name,
False,
)
def add(self, *objs, through_defaults=None):
self._remove_prefetched_objects()
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
self._add_items(
self.source_field_name,
self.target_field_name,
*objs,
through_defaults=through_defaults,
)
# If this is a symmetrical m2m relation to self, add the mirror
# entry in the m2m table.
if self.symmetrical:
self._add_items(
self.target_field_name,
self.source_field_name,
*objs,
through_defaults=through_defaults,
)
add.alters_data = True
async def aadd(self, *objs, through_defaults=None):
return await sync_to_async(self.add)(
*objs, through_defaults=through_defaults
)
aadd.alters_data = True
def remove(self, *objs):
self._remove_prefetched_objects()
self._remove_items(self.source_field_name, self.target_field_name, *objs)
remove.alters_data = True
async def aremove(self, *objs):
return await sync_to_async(self.remove)(*objs)
aremove.alters_data = True
def clear(self):
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
signals.m2m_changed.send(
sender=self.through,
action="pre_clear",
instance=self.instance,
reverse=self.reverse,
model=self.model,
pk_set=None,
using=db,
)
self._remove_prefetched_objects()
filters = self._build_remove_filters(super().get_queryset().using(db))
self.through._default_manager.using(db).filter(filters).delete()
signals.m2m_changed.send(
sender=self.through,
action="post_clear",
instance=self.instance,
reverse=self.reverse,
model=self.model,
pk_set=None,
using=db,
)
clear.alters_data = True
async def aclear(self):
return await sync_to_async(self.clear)()
aclear.alters_data = True
def set(self, objs, *, clear=False, through_defaults=None):
# Force evaluation of `objs` in case it's a queryset whose value
# could be affected by `manager.clear()`. Refs #19816.
objs = tuple(objs)
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
if clear:
self.clear()
self.add(*objs, through_defaults=through_defaults)
else:
old_ids = set(
self.using(db).values_list(
self.target_field.target_field.attname, flat=True
)
)
new_objs = []
for obj in objs:
fk_val = (
self.target_field.get_foreign_related_value(obj)[0]
if isinstance(obj, self.model)
else self.target_field.get_prep_value(obj)
)
if fk_val in old_ids:
old_ids.remove(fk_val)
else:
new_objs.append(obj)
self.remove(*old_ids)
self.add(*new_objs, through_defaults=through_defaults)
set.alters_data = True
async def aset(self, objs, *, clear=False, through_defaults=None):
return await sync_to_async(self.set)(
objs=objs, clear=clear, through_defaults=through_defaults
)
aset.alters_data = True
def create(self, *, through_defaults=None, **kwargs):
db = router.db_for_write(self.instance.__class__, instance=self.instance)
new_obj = super(ManyRelatedManager, self.db_manager(db)).create(**kwargs)
self.add(new_obj, through_defaults=through_defaults)
return new_obj
create.alters_data = True
async def acreate(self, *, through_defaults=None, **kwargs):
return await sync_to_async(self.create)(
through_defaults=through_defaults, **kwargs
)
acreate.alters_data = True
def get_or_create(self, *, through_defaults=None, **kwargs):
db = router.db_for_write(self.instance.__class__, instance=self.instance)
obj, created = super(ManyRelatedManager, self.db_manager(db)).get_or_create(
**kwargs
)
# We only need to add() if created because if we got an object back
# from get() then the relationship already exists.
if created:
self.add(obj, through_defaults=through_defaults)
return obj, created
get_or_create.alters_data = True
async def aget_or_create(self, *, through_defaults=None, **kwargs):
return await sync_to_async(self.get_or_create)(
through_defaults=through_defaults, **kwargs
)
aget_or_create.alters_data = True
def update_or_create(self, *, through_defaults=None, **kwargs):
db = router.db_for_write(self.instance.__class__, instance=self.instance)
obj, created = super(
ManyRelatedManager, self.db_manager(db)
).update_or_create(**kwargs)
# We only need to add() if created because if we got an object back
# from get() then the relationship already exists.
if created:
self.add(obj, through_defaults=through_defaults)
return obj, created
update_or_create.alters_data = True
async def aupdate_or_create(self, *, through_defaults=None, **kwargs):
return await sync_to_async(self.update_or_create)(
through_defaults=through_defaults, **kwargs
)
aupdate_or_create.alters_data = True
def _get_target_ids(self, target_field_name, objs):
"""
Return the set of ids of `objs` that the target field references.
"""
from django.db.models import Model
target_ids = set()
target_field = self.through._meta.get_field(target_field_name)
for obj in objs:
if isinstance(obj, self.model):
if not router.allow_relation(obj, self.instance):
raise ValueError(
'Cannot add "%r": instance is on database "%s", '
'value is on database "%s"'
% (obj, self.instance._state.db, obj._state.db)
)
target_id = target_field.get_foreign_related_value(obj)[0]
if target_id is None:
raise ValueError(
'Cannot add "%r": the value for field "%s" is None'
% (obj, target_field_name)
)
target_ids.add(target_id)
elif isinstance(obj, Model):
raise TypeError(
"'%s' instance expected, got %r"
% (self.model._meta.object_name, obj)
)
else:
target_ids.add(target_field.get_prep_value(obj))
return target_ids
def _get_missing_target_ids(
self, source_field_name, target_field_name, db, target_ids
):
"""
Return the subset of ids of `objs` that aren't already assigned to
this relationship.
"""
vals = (
self.through._default_manager.using(db)
.values_list(target_field_name, flat=True)
.filter(
**{
source_field_name: self.related_val[0],
"%s__in" % target_field_name: target_ids,
}
)
)
return target_ids.difference(vals)
def _get_add_plan(self, db, source_field_name):
"""
Return a boolean triple of the way the add should be performed.
The first element is whether or not bulk_create(ignore_conflicts)
can be used, the second whether or not signals must be sent, and
the third element is whether or not the immediate bulk insertion
with conflicts ignored can be performed.
"""
# Conflicts can be ignored when the intermediary model is
# auto-created as the only possible collision is on the
# (source_id, target_id) tuple. The same assertion doesn't hold for
# user-defined intermediary models as they could have other fields
# causing conflicts which must be surfaced.
can_ignore_conflicts = (
self.through._meta.auto_created is not False
and connections[db].features.supports_ignore_conflicts
)
# Don't send the signal when inserting duplicate data row
# for symmetrical reverse entries.
must_send_signals = (
self.reverse or source_field_name == self.source_field_name
) and (signals.m2m_changed.has_listeners(self.through))
# Fast addition through bulk insertion can only be performed
# if no m2m_changed listeners are connected for self.through
# as they require the added set of ids to be provided via
# pk_set.
return (
can_ignore_conflicts,
must_send_signals,
(can_ignore_conflicts and not must_send_signals),
)
def _add_items(
self, source_field_name, target_field_name, *objs, through_defaults=None
):
# source_field_name: the PK fieldname in join table for the source object
# target_field_name: the PK fieldname in join table for the target object
# *objs - objects to add. Either object instances, or primary keys
# of object instances.
if not objs:
return
through_defaults = dict(resolve_callables(through_defaults or {}))
target_ids = self._get_target_ids(target_field_name, objs)
db = router.db_for_write(self.through, instance=self.instance)
can_ignore_conflicts, must_send_signals, can_fast_add = self._get_add_plan(
db, source_field_name
)
if can_fast_add:
self.through._default_manager.using(db).bulk_create(
[
self.through(
**{
"%s_id" % source_field_name: self.related_val[0],
"%s_id" % target_field_name: target_id,
}
)
for target_id in target_ids
],
ignore_conflicts=True,
)
return
missing_target_ids = self._get_missing_target_ids(
source_field_name, target_field_name, db, target_ids
)
with transaction.atomic(using=db, savepoint=False):
if must_send_signals:
signals.m2m_changed.send(
sender=self.through,
action="pre_add",
instance=self.instance,
reverse=self.reverse,
model=self.model,
pk_set=missing_target_ids,
using=db,
)
# Add the ones that aren't there already.
self.through._default_manager.using(db).bulk_create(
[
self.through(
**through_defaults,
**{
"%s_id" % source_field_name: self.related_val[0],
"%s_id" % target_field_name: target_id,
},
)
for target_id in missing_target_ids
],
ignore_conflicts=can_ignore_conflicts,
)
if must_send_signals:
signals.m2m_changed.send(
sender=self.through,
action="post_add",
instance=self.instance,
reverse=self.reverse,
model=self.model,
pk_set=missing_target_ids,
using=db,
)
def _remove_items(self, source_field_name, target_field_name, *objs):
# source_field_name: the PK colname in join table for the source object
# target_field_name: the PK colname in join table for the target object
# *objs - objects to remove. Either object instances, or primary
# keys of object instances.
if not objs:
return
# Check that all the objects are of the right type
old_ids = set()
for obj in objs:
if isinstance(obj, self.model):
fk_val = self.target_field.get_foreign_related_value(obj)[0]
old_ids.add(fk_val)
else:
old_ids.add(obj)
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
# Send a signal to the other end if need be.
signals.m2m_changed.send(
sender=self.through,
action="pre_remove",
instance=self.instance,
reverse=self.reverse,
model=self.model,
pk_set=old_ids,
using=db,
)
target_model_qs = super().get_queryset()
if target_model_qs._has_filters():
old_vals = target_model_qs.using(db).filter(
**{"%s__in" % self.target_field.target_field.attname: old_ids}
)
else:
old_vals = old_ids
filters = self._build_remove_filters(old_vals)
self.through._default_manager.using(db).filter(filters).delete()
signals.m2m_changed.send(
sender=self.through,
action="post_remove",
instance=self.instance,
reverse=self.reverse,
model=self.model,
pk_set=old_ids,
using=db,
)
return ManyRelatedManager
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/related_descriptors.py
|
Python
|
mit
| 61,824 |
import warnings
from django.db.models.lookups import (
Exact,
GreaterThan,
GreaterThanOrEqual,
In,
IsNull,
LessThan,
LessThanOrEqual,
)
from django.utils.deprecation import RemovedInDjango50Warning
class MultiColSource:
contains_aggregate = False
contains_over_clause = False
def __init__(self, alias, targets, sources, field):
self.targets, self.sources, self.field, self.alias = (
targets,
sources,
field,
alias,
)
self.output_field = self.field
def __repr__(self):
return "{}({}, {})".format(self.__class__.__name__, self.alias, self.field)
def relabeled_clone(self, relabels):
return self.__class__(
relabels.get(self.alias, self.alias), self.targets, self.sources, self.field
)
def get_lookup(self, lookup):
return self.output_field.get_lookup(lookup)
def resolve_expression(self, *args, **kwargs):
return self
def get_normalized_value(value, lhs):
from django.db.models import Model
if isinstance(value, Model):
if value.pk is None:
# When the deprecation ends, replace with:
# raise ValueError(
# "Model instances passed to related filters must be saved."
# )
warnings.warn(
"Passing unsaved model instances to related filters is deprecated.",
RemovedInDjango50Warning,
)
value_list = []
sources = lhs.output_field.path_infos[-1].target_fields
for source in sources:
while not isinstance(value, source.model) and source.remote_field:
source = source.remote_field.model._meta.get_field(
source.remote_field.field_name
)
try:
value_list.append(getattr(value, source.attname))
except AttributeError:
# A case like Restaurant.objects.filter(place=restaurant_instance),
# where place is a OneToOneField and the primary key of Restaurant.
return (value.pk,)
return tuple(value_list)
if not isinstance(value, tuple):
return (value,)
return value
class RelatedIn(In):
def get_prep_lookup(self):
if not isinstance(self.lhs, MultiColSource):
if self.rhs_is_direct_value():
# If we get here, we are dealing with single-column relations.
self.rhs = [get_normalized_value(val, self.lhs)[0] for val in self.rhs]
# We need to run the related field's get_prep_value(). Consider
# case ForeignKey to IntegerField given value 'abc'. The
# ForeignKey itself doesn't have validation for non-integers,
# so we must run validation using the target field.
if hasattr(self.lhs.output_field, "path_infos"):
# Run the target field's get_prep_value. We can safely
# assume there is only one as we don't get to the direct
# value branch otherwise.
target_field = self.lhs.output_field.path_infos[-1].target_fields[
-1
]
self.rhs = [target_field.get_prep_value(v) for v in self.rhs]
elif not getattr(self.rhs, "has_select_fields", True) and not getattr(
self.lhs.field.target_field, "primary_key", False
):
if (
getattr(self.lhs.output_field, "primary_key", False)
and self.lhs.output_field.model == self.rhs.model
):
# A case like
# Restaurant.objects.filter(place__in=restaurant_qs), where
# place is a OneToOneField and the primary key of
# Restaurant.
target_field = self.lhs.field.name
else:
target_field = self.lhs.field.target_field.name
self.rhs.set_values([target_field])
return super().get_prep_lookup()
def as_sql(self, compiler, connection):
if isinstance(self.lhs, MultiColSource):
# For multicolumn lookups we need to build a multicolumn where clause.
# This clause is either a SubqueryConstraint (for values that need
# to be compiled to SQL) or an OR-combined list of
# (col1 = val1 AND col2 = val2 AND ...) clauses.
from django.db.models.sql.where import (
AND,
OR,
SubqueryConstraint,
WhereNode,
)
root_constraint = WhereNode(connector=OR)
if self.rhs_is_direct_value():
values = [get_normalized_value(value, self.lhs) for value in self.rhs]
for value in values:
value_constraint = WhereNode()
for source, target, val in zip(
self.lhs.sources, self.lhs.targets, value
):
lookup_class = target.get_lookup("exact")
lookup = lookup_class(
target.get_col(self.lhs.alias, source), val
)
value_constraint.add(lookup, AND)
root_constraint.add(value_constraint, OR)
else:
root_constraint.add(
SubqueryConstraint(
self.lhs.alias,
[target.column for target in self.lhs.targets],
[source.name for source in self.lhs.sources],
self.rhs,
),
AND,
)
return root_constraint.as_sql(compiler, connection)
return super().as_sql(compiler, connection)
class RelatedLookupMixin:
def get_prep_lookup(self):
if not isinstance(self.lhs, MultiColSource) and not hasattr(
self.rhs, "resolve_expression"
):
# If we get here, we are dealing with single-column relations.
self.rhs = get_normalized_value(self.rhs, self.lhs)[0]
# We need to run the related field's get_prep_value(). Consider case
# ForeignKey to IntegerField given value 'abc'. The ForeignKey itself
# doesn't have validation for non-integers, so we must run validation
# using the target field.
if self.prepare_rhs and hasattr(self.lhs.output_field, "path_infos"):
# Get the target field. We can safely assume there is only one
# as we don't get to the direct value branch otherwise.
target_field = self.lhs.output_field.path_infos[-1].target_fields[-1]
self.rhs = target_field.get_prep_value(self.rhs)
return super().get_prep_lookup()
def as_sql(self, compiler, connection):
if isinstance(self.lhs, MultiColSource):
assert self.rhs_is_direct_value()
self.rhs = get_normalized_value(self.rhs, self.lhs)
from django.db.models.sql.where import AND, WhereNode
root_constraint = WhereNode()
for target, source, val in zip(
self.lhs.targets, self.lhs.sources, self.rhs
):
lookup_class = target.get_lookup(self.lookup_name)
root_constraint.add(
lookup_class(target.get_col(self.lhs.alias, source), val), AND
)
return root_constraint.as_sql(compiler, connection)
return super().as_sql(compiler, connection)
class RelatedExact(RelatedLookupMixin, Exact):
pass
class RelatedLessThan(RelatedLookupMixin, LessThan):
pass
class RelatedGreaterThan(RelatedLookupMixin, GreaterThan):
pass
class RelatedGreaterThanOrEqual(RelatedLookupMixin, GreaterThanOrEqual):
pass
class RelatedLessThanOrEqual(RelatedLookupMixin, LessThanOrEqual):
pass
class RelatedIsNull(RelatedLookupMixin, IsNull):
pass
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/related_lookups.py
|
Python
|
mit
| 8,151 |
"""
"Rel objects" for related fields.
"Rel objects" (for lack of a better name) carry information about the relation
modeled by a related field and provide some utility functions. They're stored
in the ``remote_field`` attribute of the field.
They also act as reverse fields for the purposes of the Meta API because
they're the closest concept currently available.
"""
from django.core import exceptions
from django.utils.functional import cached_property
from django.utils.hashable import make_hashable
from . import BLANK_CHOICE_DASH
from .mixins import FieldCacheMixin
class ForeignObjectRel(FieldCacheMixin):
"""
Used by ForeignObject to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
# Field flags
auto_created = True
concrete = False
editable = False
is_relation = True
# Reverse relations are always nullable (Django can't enforce that a
# foreign key on the related model points to this model).
null = True
empty_strings_allowed = False
def __init__(
self,
field,
to,
related_name=None,
related_query_name=None,
limit_choices_to=None,
parent_link=False,
on_delete=None,
):
self.field = field
self.model = to
self.related_name = related_name
self.related_query_name = related_query_name
self.limit_choices_to = {} if limit_choices_to is None else limit_choices_to
self.parent_link = parent_link
self.on_delete = on_delete
self.symmetrical = False
self.multiple = True
# Some of the following cached_properties can't be initialized in
# __init__ as the field doesn't have its model yet. Calling these methods
# before field.contribute_to_class() has been called will result in
# AttributeError
@cached_property
def hidden(self):
return self.is_hidden()
@cached_property
def name(self):
return self.field.related_query_name()
@property
def remote_field(self):
return self.field
@property
def target_field(self):
"""
When filtering against this relation, return the field on the remote
model against which the filtering should happen.
"""
target_fields = self.path_infos[-1].target_fields
if len(target_fields) > 1:
raise exceptions.FieldError(
"Can't use target_field for multicolumn relations."
)
return target_fields[0]
@cached_property
def related_model(self):
if not self.field.model:
raise AttributeError(
"This property can't be accessed before self.field.contribute_to_class "
"has been called."
)
return self.field.model
@cached_property
def many_to_many(self):
return self.field.many_to_many
@cached_property
def many_to_one(self):
return self.field.one_to_many
@cached_property
def one_to_many(self):
return self.field.many_to_one
@cached_property
def one_to_one(self):
return self.field.one_to_one
def get_lookup(self, lookup_name):
return self.field.get_lookup(lookup_name)
def get_lookups(self):
return self.field.get_lookups()
def get_transform(self, name):
return self.field.get_transform(name)
def get_internal_type(self):
return self.field.get_internal_type()
@property
def db_type(self):
return self.field.db_type
def __repr__(self):
return "<%s: %s.%s>" % (
type(self).__name__,
self.related_model._meta.app_label,
self.related_model._meta.model_name,
)
@property
def identity(self):
return (
self.field,
self.model,
self.related_name,
self.related_query_name,
make_hashable(self.limit_choices_to),
self.parent_link,
self.on_delete,
self.symmetrical,
self.multiple,
)
def __eq__(self, other):
if not isinstance(other, self.__class__):
return NotImplemented
return self.identity == other.identity
def __hash__(self):
return hash(self.identity)
def __getstate__(self):
state = self.__dict__.copy()
# Delete the path_infos cached property because it can be recalculated
# at first invocation after deserialization. The attribute must be
# removed because subclasses like ManyToOneRel may have a PathInfo
# which contains an intermediate M2M table that's been dynamically
# created and doesn't exist in the .models module.
# This is a reverse relation, so there is no reverse_path_infos to
# delete.
state.pop("path_infos", None)
return state
def get_choices(
self,
include_blank=True,
blank_choice=BLANK_CHOICE_DASH,
limit_choices_to=None,
ordering=(),
):
"""
Return choices with a default blank choices included, for use
as <select> choices for this field.
Analog of django.db.models.fields.Field.get_choices(), provided
initially for utilization by RelatedFieldListFilter.
"""
limit_choices_to = limit_choices_to or self.limit_choices_to
qs = self.related_model._default_manager.complex_filter(limit_choices_to)
if ordering:
qs = qs.order_by(*ordering)
return (blank_choice if include_blank else []) + [(x.pk, str(x)) for x in qs]
def is_hidden(self):
"""Should the related object be hidden?"""
return bool(self.related_name) and self.related_name[-1] == "+"
def get_joining_columns(self):
return self.field.get_reverse_joining_columns()
def get_extra_restriction(self, alias, related_alias):
return self.field.get_extra_restriction(related_alias, alias)
def set_field_name(self):
"""
Set the related field's name, this is not available until later stages
of app loading, so set_field_name is called from
set_attributes_from_rel()
"""
# By default foreign object doesn't relate to any remote field (for
# example custom multicolumn joins currently have no remote field).
self.field_name = None
def get_accessor_name(self, model=None):
# This method encapsulates the logic that decides what name to give an
# accessor descriptor that retrieves related many-to-one or
# many-to-many objects. It uses the lowercased object_name + "_set",
# but this can be overridden with the "related_name" option. Due to
# backwards compatibility ModelForms need to be able to provide an
# alternate model. See BaseInlineFormSet.get_default_prefix().
opts = model._meta if model else self.related_model._meta
model = model or self.related_model
if self.multiple:
# If this is a symmetrical m2m relation on self, there is no
# reverse accessor.
if self.symmetrical and model == self.model:
return None
if self.related_name:
return self.related_name
return opts.model_name + ("_set" if self.multiple else "")
def get_path_info(self, filtered_relation=None):
if filtered_relation:
return self.field.get_reverse_path_info(filtered_relation)
else:
return self.field.reverse_path_infos
@cached_property
def path_infos(self):
return self.get_path_info()
def get_cache_name(self):
"""
Return the name of the cache key to use for storing an instance of the
forward model on the reverse model.
"""
return self.get_accessor_name()
class ManyToOneRel(ForeignObjectRel):
"""
Used by the ForeignKey field to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
Note: Because we somewhat abuse the Rel objects by using them as reverse
fields we get the funny situation where
``ManyToOneRel.many_to_one == False`` and
``ManyToOneRel.one_to_many == True``. This is unfortunate but the actual
ManyToOneRel class is a private API and there is work underway to turn
reverse relations into actual fields.
"""
def __init__(
self,
field,
to,
field_name,
related_name=None,
related_query_name=None,
limit_choices_to=None,
parent_link=False,
on_delete=None,
):
super().__init__(
field,
to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
self.field_name = field_name
def __getstate__(self):
state = super().__getstate__()
state.pop("related_model", None)
return state
@property
def identity(self):
return super().identity + (self.field_name,)
def get_related_field(self):
"""
Return the Field in the 'to' object to which this relationship is tied.
"""
field = self.model._meta.get_field(self.field_name)
if not field.concrete:
raise exceptions.FieldDoesNotExist(
"No related field named '%s'" % self.field_name
)
return field
def set_field_name(self):
self.field_name = self.field_name or self.model._meta.pk.name
class OneToOneRel(ManyToOneRel):
"""
Used by OneToOneField to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
def __init__(
self,
field,
to,
field_name,
related_name=None,
related_query_name=None,
limit_choices_to=None,
parent_link=False,
on_delete=None,
):
super().__init__(
field,
to,
field_name,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
self.multiple = False
class ManyToManyRel(ForeignObjectRel):
"""
Used by ManyToManyField to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
def __init__(
self,
field,
to,
related_name=None,
related_query_name=None,
limit_choices_to=None,
symmetrical=True,
through=None,
through_fields=None,
db_constraint=True,
):
super().__init__(
field,
to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
)
if through and not db_constraint:
raise ValueError("Can't supply a through model and db_constraint=False")
self.through = through
if through_fields and not through:
raise ValueError("Cannot specify through_fields without a through model")
self.through_fields = through_fields
self.symmetrical = symmetrical
self.db_constraint = db_constraint
@property
def identity(self):
return super().identity + (
self.through,
make_hashable(self.through_fields),
self.db_constraint,
)
def get_related_field(self):
"""
Return the field in the 'to' object to which this relationship is tied.
Provided for symmetry with ManyToOneRel.
"""
opts = self.through._meta
if self.through_fields:
field = opts.get_field(self.through_fields[0])
else:
for field in opts.fields:
rel = getattr(field, "remote_field", None)
if rel and rel.model == self.model:
break
return field.foreign_related_fields[0]
|
castiel248/Convert
|
Lib/site-packages/django/db/models/fields/reverse_related.py
|
Python
|
mit
| 12,480 |
from .comparison import Cast, Coalesce, Collate, Greatest, JSONObject, Least, NullIf
from .datetime import (
Extract,
ExtractDay,
ExtractHour,
ExtractIsoWeekDay,
ExtractIsoYear,
ExtractMinute,
ExtractMonth,
ExtractQuarter,
ExtractSecond,
ExtractWeek,
ExtractWeekDay,
ExtractYear,
Now,
Trunc,
TruncDate,
TruncDay,
TruncHour,
TruncMinute,
TruncMonth,
TruncQuarter,
TruncSecond,
TruncTime,
TruncWeek,
TruncYear,
)
from .math import (
Abs,
ACos,
ASin,
ATan,
ATan2,
Ceil,
Cos,
Cot,
Degrees,
Exp,
Floor,
Ln,
Log,
Mod,
Pi,
Power,
Radians,
Random,
Round,
Sign,
Sin,
Sqrt,
Tan,
)
from .text import (
MD5,
SHA1,
SHA224,
SHA256,
SHA384,
SHA512,
Chr,
Concat,
ConcatPair,
Left,
Length,
Lower,
LPad,
LTrim,
Ord,
Repeat,
Replace,
Reverse,
Right,
RPad,
RTrim,
StrIndex,
Substr,
Trim,
Upper,
)
from .window import (
CumeDist,
DenseRank,
FirstValue,
Lag,
LastValue,
Lead,
NthValue,
Ntile,
PercentRank,
Rank,
RowNumber,
)
__all__ = [
# comparison and conversion
"Cast",
"Coalesce",
"Collate",
"Greatest",
"JSONObject",
"Least",
"NullIf",
# datetime
"Extract",
"ExtractDay",
"ExtractHour",
"ExtractMinute",
"ExtractMonth",
"ExtractQuarter",
"ExtractSecond",
"ExtractWeek",
"ExtractIsoWeekDay",
"ExtractWeekDay",
"ExtractIsoYear",
"ExtractYear",
"Now",
"Trunc",
"TruncDate",
"TruncDay",
"TruncHour",
"TruncMinute",
"TruncMonth",
"TruncQuarter",
"TruncSecond",
"TruncTime",
"TruncWeek",
"TruncYear",
# math
"Abs",
"ACos",
"ASin",
"ATan",
"ATan2",
"Ceil",
"Cos",
"Cot",
"Degrees",
"Exp",
"Floor",
"Ln",
"Log",
"Mod",
"Pi",
"Power",
"Radians",
"Random",
"Round",
"Sign",
"Sin",
"Sqrt",
"Tan",
# text
"MD5",
"SHA1",
"SHA224",
"SHA256",
"SHA384",
"SHA512",
"Chr",
"Concat",
"ConcatPair",
"Left",
"Length",
"Lower",
"LPad",
"LTrim",
"Ord",
"Repeat",
"Replace",
"Reverse",
"Right",
"RPad",
"RTrim",
"StrIndex",
"Substr",
"Trim",
"Upper",
# window
"CumeDist",
"DenseRank",
"FirstValue",
"Lag",
"LastValue",
"Lead",
"NthValue",
"Ntile",
"PercentRank",
"Rank",
"RowNumber",
]
|
castiel248/Convert
|
Lib/site-packages/django/db/models/functions/__init__.py
|
Python
|
mit
| 2,658 |
"""Database functions that do comparisons or type conversions."""
from django.db import NotSupportedError
from django.db.models.expressions import Func, Value
from django.db.models.fields import TextField
from django.db.models.fields.json import JSONField
from django.utils.regex_helper import _lazy_re_compile
class Cast(Func):
"""Coerce an expression to a new field type."""
function = "CAST"
template = "%(function)s(%(expressions)s AS %(db_type)s)"
def __init__(self, expression, output_field):
super().__init__(expression, output_field=output_field)
def as_sql(self, compiler, connection, **extra_context):
extra_context["db_type"] = self.output_field.cast_db_type(connection)
return super().as_sql(compiler, connection, **extra_context)
def as_sqlite(self, compiler, connection, **extra_context):
db_type = self.output_field.db_type(connection)
if db_type in {"datetime", "time"}:
# Use strftime as datetime/time don't keep fractional seconds.
template = "strftime(%%s, %(expressions)s)"
sql, params = super().as_sql(
compiler, connection, template=template, **extra_context
)
format_string = "%H:%M:%f" if db_type == "time" else "%Y-%m-%d %H:%M:%f"
params.insert(0, format_string)
return sql, params
elif db_type == "date":
template = "date(%(expressions)s)"
return super().as_sql(
compiler, connection, template=template, **extra_context
)
return self.as_sql(compiler, connection, **extra_context)
def as_mysql(self, compiler, connection, **extra_context):
template = None
output_type = self.output_field.get_internal_type()
# MySQL doesn't support explicit cast to float.
if output_type == "FloatField":
template = "(%(expressions)s + 0.0)"
# MariaDB doesn't support explicit cast to JSON.
elif output_type == "JSONField" and connection.mysql_is_mariadb:
template = "JSON_EXTRACT(%(expressions)s, '$')"
return self.as_sql(compiler, connection, template=template, **extra_context)
def as_postgresql(self, compiler, connection, **extra_context):
# CAST would be valid too, but the :: shortcut syntax is more readable.
# 'expressions' is wrapped in parentheses in case it's a complex
# expression.
return self.as_sql(
compiler,
connection,
template="(%(expressions)s)::%(db_type)s",
**extra_context,
)
def as_oracle(self, compiler, connection, **extra_context):
if self.output_field.get_internal_type() == "JSONField":
# Oracle doesn't support explicit cast to JSON.
template = "JSON_QUERY(%(expressions)s, '$')"
return super().as_sql(
compiler, connection, template=template, **extra_context
)
return self.as_sql(compiler, connection, **extra_context)
class Coalesce(Func):
"""Return, from left to right, the first non-null expression."""
function = "COALESCE"
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError("Coalesce must take at least two expressions")
super().__init__(*expressions, **extra)
@property
def empty_result_set_value(self):
for expression in self.get_source_expressions():
result = expression.empty_result_set_value
if result is NotImplemented or result is not None:
return result
return None
def as_oracle(self, compiler, connection, **extra_context):
# Oracle prohibits mixing TextField (NCLOB) and CharField (NVARCHAR2),
# so convert all fields to NCLOB when that type is expected.
if self.output_field.get_internal_type() == "TextField":
clone = self.copy()
clone.set_source_expressions(
[
Func(expression, function="TO_NCLOB")
for expression in self.get_source_expressions()
]
)
return super(Coalesce, clone).as_sql(compiler, connection, **extra_context)
return self.as_sql(compiler, connection, **extra_context)
class Collate(Func):
function = "COLLATE"
template = "%(expressions)s %(function)s %(collation)s"
# Inspired from
# https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS
collation_re = _lazy_re_compile(r"^[\w\-]+$")
def __init__(self, expression, collation):
if not (collation and self.collation_re.match(collation)):
raise ValueError("Invalid collation name: %r." % collation)
self.collation = collation
super().__init__(expression)
def as_sql(self, compiler, connection, **extra_context):
extra_context.setdefault("collation", connection.ops.quote_name(self.collation))
return super().as_sql(compiler, connection, **extra_context)
class Greatest(Func):
"""
Return the maximum expression.
If any expression is null the return value is database-specific:
On PostgreSQL, the maximum not-null expression is returned.
On MySQL, Oracle, and SQLite, if any expression is null, null is returned.
"""
function = "GREATEST"
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError("Greatest must take at least two expressions")
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection, **extra_context):
"""Use the MAX function on SQLite."""
return super().as_sqlite(compiler, connection, function="MAX", **extra_context)
class JSONObject(Func):
function = "JSON_OBJECT"
output_field = JSONField()
def __init__(self, **fields):
expressions = []
for key, value in fields.items():
expressions.extend((Value(key), value))
super().__init__(*expressions)
def as_sql(self, compiler, connection, **extra_context):
if not connection.features.has_json_object_function:
raise NotSupportedError(
"JSONObject() is not supported on this database backend."
)
return super().as_sql(compiler, connection, **extra_context)
def as_postgresql(self, compiler, connection, **extra_context):
copy = self.copy()
copy.set_source_expressions(
[
Cast(expression, TextField()) if index % 2 == 0 else expression
for index, expression in enumerate(copy.get_source_expressions())
]
)
return super(JSONObject, copy).as_sql(
compiler,
connection,
function="JSONB_BUILD_OBJECT",
**extra_context,
)
def as_oracle(self, compiler, connection, **extra_context):
class ArgJoiner:
def join(self, args):
args = [" VALUE ".join(arg) for arg in zip(args[::2], args[1::2])]
return ", ".join(args)
return self.as_sql(
compiler,
connection,
arg_joiner=ArgJoiner(),
template="%(function)s(%(expressions)s RETURNING CLOB)",
**extra_context,
)
class Least(Func):
"""
Return the minimum expression.
If any expression is null the return value is database-specific:
On PostgreSQL, return the minimum not-null expression.
On MySQL, Oracle, and SQLite, if any expression is null, return null.
"""
function = "LEAST"
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError("Least must take at least two expressions")
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection, **extra_context):
"""Use the MIN function on SQLite."""
return super().as_sqlite(compiler, connection, function="MIN", **extra_context)
class NullIf(Func):
function = "NULLIF"
arity = 2
def as_oracle(self, compiler, connection, **extra_context):
expression1 = self.get_source_expressions()[0]
if isinstance(expression1, Value) and expression1.value is None:
raise ValueError("Oracle does not allow Value(None) for expression1.")
return super().as_sql(compiler, connection, **extra_context)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/functions/comparison.py
|
Python
|
mit
| 8,488 |
from datetime import datetime
from django.conf import settings
from django.db.models.expressions import Func
from django.db.models.fields import (
DateField,
DateTimeField,
DurationField,
Field,
IntegerField,
TimeField,
)
from django.db.models.lookups import (
Transform,
YearExact,
YearGt,
YearGte,
YearLt,
YearLte,
)
from django.utils import timezone
class TimezoneMixin:
tzinfo = None
def get_tzname(self):
# Timezone conversions must happen to the input datetime *before*
# applying a function. 2015-12-31 23:00:00 -02:00 is stored in the
# database as 2016-01-01 01:00:00 +00:00. Any results should be
# based on the input datetime not the stored datetime.
tzname = None
if settings.USE_TZ:
if self.tzinfo is None:
tzname = timezone.get_current_timezone_name()
else:
tzname = timezone._get_timezone_name(self.tzinfo)
return tzname
class Extract(TimezoneMixin, Transform):
lookup_name = None
output_field = IntegerField()
def __init__(self, expression, lookup_name=None, tzinfo=None, **extra):
if self.lookup_name is None:
self.lookup_name = lookup_name
if self.lookup_name is None:
raise ValueError("lookup_name must be provided")
self.tzinfo = tzinfo
super().__init__(expression, **extra)
def as_sql(self, compiler, connection):
sql, params = compiler.compile(self.lhs)
lhs_output_field = self.lhs.output_field
if isinstance(lhs_output_field, DateTimeField):
tzname = self.get_tzname()
sql, params = connection.ops.datetime_extract_sql(
self.lookup_name, sql, tuple(params), tzname
)
elif self.tzinfo is not None:
raise ValueError("tzinfo can only be used with DateTimeField.")
elif isinstance(lhs_output_field, DateField):
sql, params = connection.ops.date_extract_sql(
self.lookup_name, sql, tuple(params)
)
elif isinstance(lhs_output_field, TimeField):
sql, params = connection.ops.time_extract_sql(
self.lookup_name, sql, tuple(params)
)
elif isinstance(lhs_output_field, DurationField):
if not connection.features.has_native_duration_field:
raise ValueError(
"Extract requires native DurationField database support."
)
sql, params = connection.ops.time_extract_sql(
self.lookup_name, sql, tuple(params)
)
else:
# resolve_expression has already validated the output_field so this
# assert should never be hit.
assert False, "Tried to Extract from an invalid type."
return sql, params
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
copy = super().resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
field = getattr(copy.lhs, "output_field", None)
if field is None:
return copy
if not isinstance(field, (DateField, DateTimeField, TimeField, DurationField)):
raise ValueError(
"Extract input expression must be DateField, DateTimeField, "
"TimeField, or DurationField."
)
# Passing dates to functions expecting datetimes is most likely a mistake.
if type(field) == DateField and copy.lookup_name in (
"hour",
"minute",
"second",
):
raise ValueError(
"Cannot extract time component '%s' from DateField '%s'."
% (copy.lookup_name, field.name)
)
if isinstance(field, DurationField) and copy.lookup_name in (
"year",
"iso_year",
"month",
"week",
"week_day",
"iso_week_day",
"quarter",
):
raise ValueError(
"Cannot extract component '%s' from DurationField '%s'."
% (copy.lookup_name, field.name)
)
return copy
class ExtractYear(Extract):
lookup_name = "year"
class ExtractIsoYear(Extract):
"""Return the ISO-8601 week-numbering year."""
lookup_name = "iso_year"
class ExtractMonth(Extract):
lookup_name = "month"
class ExtractDay(Extract):
lookup_name = "day"
class ExtractWeek(Extract):
"""
Return 1-52 or 53, based on ISO-8601, i.e., Monday is the first of the
week.
"""
lookup_name = "week"
class ExtractWeekDay(Extract):
"""
Return Sunday=1 through Saturday=7.
To replicate this in Python: (mydatetime.isoweekday() % 7) + 1
"""
lookup_name = "week_day"
class ExtractIsoWeekDay(Extract):
"""Return Monday=1 through Sunday=7, based on ISO-8601."""
lookup_name = "iso_week_day"
class ExtractQuarter(Extract):
lookup_name = "quarter"
class ExtractHour(Extract):
lookup_name = "hour"
class ExtractMinute(Extract):
lookup_name = "minute"
class ExtractSecond(Extract):
lookup_name = "second"
DateField.register_lookup(ExtractYear)
DateField.register_lookup(ExtractMonth)
DateField.register_lookup(ExtractDay)
DateField.register_lookup(ExtractWeekDay)
DateField.register_lookup(ExtractIsoWeekDay)
DateField.register_lookup(ExtractWeek)
DateField.register_lookup(ExtractIsoYear)
DateField.register_lookup(ExtractQuarter)
TimeField.register_lookup(ExtractHour)
TimeField.register_lookup(ExtractMinute)
TimeField.register_lookup(ExtractSecond)
DateTimeField.register_lookup(ExtractHour)
DateTimeField.register_lookup(ExtractMinute)
DateTimeField.register_lookup(ExtractSecond)
ExtractYear.register_lookup(YearExact)
ExtractYear.register_lookup(YearGt)
ExtractYear.register_lookup(YearGte)
ExtractYear.register_lookup(YearLt)
ExtractYear.register_lookup(YearLte)
ExtractIsoYear.register_lookup(YearExact)
ExtractIsoYear.register_lookup(YearGt)
ExtractIsoYear.register_lookup(YearGte)
ExtractIsoYear.register_lookup(YearLt)
ExtractIsoYear.register_lookup(YearLte)
class Now(Func):
template = "CURRENT_TIMESTAMP"
output_field = DateTimeField()
def as_postgresql(self, compiler, connection, **extra_context):
# PostgreSQL's CURRENT_TIMESTAMP means "the time at the start of the
# transaction". Use STATEMENT_TIMESTAMP to be cross-compatible with
# other databases.
return self.as_sql(
compiler, connection, template="STATEMENT_TIMESTAMP()", **extra_context
)
def as_mysql(self, compiler, connection, **extra_context):
return self.as_sql(
compiler, connection, template="CURRENT_TIMESTAMP(6)", **extra_context
)
def as_sqlite(self, compiler, connection, **extra_context):
return self.as_sql(
compiler,
connection,
template="STRFTIME('%%%%Y-%%%%m-%%%%d %%%%H:%%%%M:%%%%f', 'NOW')",
**extra_context,
)
class TruncBase(TimezoneMixin, Transform):
kind = None
tzinfo = None
# RemovedInDjango50Warning: when the deprecation ends, remove is_dst
# argument.
def __init__(
self,
expression,
output_field=None,
tzinfo=None,
is_dst=timezone.NOT_PASSED,
**extra,
):
self.tzinfo = tzinfo
self.is_dst = is_dst
super().__init__(expression, output_field=output_field, **extra)
def as_sql(self, compiler, connection):
sql, params = compiler.compile(self.lhs)
tzname = None
if isinstance(self.lhs.output_field, DateTimeField):
tzname = self.get_tzname()
elif self.tzinfo is not None:
raise ValueError("tzinfo can only be used with DateTimeField.")
if isinstance(self.output_field, DateTimeField):
sql, params = connection.ops.datetime_trunc_sql(
self.kind, sql, tuple(params), tzname
)
elif isinstance(self.output_field, DateField):
sql, params = connection.ops.date_trunc_sql(
self.kind, sql, tuple(params), tzname
)
elif isinstance(self.output_field, TimeField):
sql, params = connection.ops.time_trunc_sql(
self.kind, sql, tuple(params), tzname
)
else:
raise ValueError(
"Trunc only valid on DateField, TimeField, or DateTimeField."
)
return sql, params
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
copy = super().resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
field = copy.lhs.output_field
# DateTimeField is a subclass of DateField so this works for both.
if not isinstance(field, (DateField, TimeField)):
raise TypeError(
"%r isn't a DateField, TimeField, or DateTimeField." % field.name
)
# If self.output_field was None, then accessing the field will trigger
# the resolver to assign it to self.lhs.output_field.
if not isinstance(copy.output_field, (DateField, DateTimeField, TimeField)):
raise ValueError(
"output_field must be either DateField, TimeField, or DateTimeField"
)
# Passing dates or times to functions expecting datetimes is most
# likely a mistake.
class_output_field = (
self.__class__.output_field
if isinstance(self.__class__.output_field, Field)
else None
)
output_field = class_output_field or copy.output_field
has_explicit_output_field = (
class_output_field or field.__class__ is not copy.output_field.__class__
)
if type(field) == DateField and (
isinstance(output_field, DateTimeField)
or copy.kind in ("hour", "minute", "second", "time")
):
raise ValueError(
"Cannot truncate DateField '%s' to %s."
% (
field.name,
output_field.__class__.__name__
if has_explicit_output_field
else "DateTimeField",
)
)
elif isinstance(field, TimeField) and (
isinstance(output_field, DateTimeField)
or copy.kind in ("year", "quarter", "month", "week", "day", "date")
):
raise ValueError(
"Cannot truncate TimeField '%s' to %s."
% (
field.name,
output_field.__class__.__name__
if has_explicit_output_field
else "DateTimeField",
)
)
return copy
def convert_value(self, value, expression, connection):
if isinstance(self.output_field, DateTimeField):
if not settings.USE_TZ:
pass
elif value is not None:
value = value.replace(tzinfo=None)
value = timezone.make_aware(value, self.tzinfo, is_dst=self.is_dst)
elif not connection.features.has_zoneinfo_database:
raise ValueError(
"Database returned an invalid datetime value. Are time "
"zone definitions for your database installed?"
)
elif isinstance(value, datetime):
if value is None:
pass
elif isinstance(self.output_field, DateField):
value = value.date()
elif isinstance(self.output_field, TimeField):
value = value.time()
return value
class Trunc(TruncBase):
# RemovedInDjango50Warning: when the deprecation ends, remove is_dst
# argument.
def __init__(
self,
expression,
kind,
output_field=None,
tzinfo=None,
is_dst=timezone.NOT_PASSED,
**extra,
):
self.kind = kind
super().__init__(
expression, output_field=output_field, tzinfo=tzinfo, is_dst=is_dst, **extra
)
class TruncYear(TruncBase):
kind = "year"
class TruncQuarter(TruncBase):
kind = "quarter"
class TruncMonth(TruncBase):
kind = "month"
class TruncWeek(TruncBase):
"""Truncate to midnight on the Monday of the week."""
kind = "week"
class TruncDay(TruncBase):
kind = "day"
class TruncDate(TruncBase):
kind = "date"
lookup_name = "date"
output_field = DateField()
def as_sql(self, compiler, connection):
# Cast to date rather than truncate to date.
sql, params = compiler.compile(self.lhs)
tzname = self.get_tzname()
return connection.ops.datetime_cast_date_sql(sql, tuple(params), tzname)
class TruncTime(TruncBase):
kind = "time"
lookup_name = "time"
output_field = TimeField()
def as_sql(self, compiler, connection):
# Cast to time rather than truncate to time.
sql, params = compiler.compile(self.lhs)
tzname = self.get_tzname()
return connection.ops.datetime_cast_time_sql(sql, tuple(params), tzname)
class TruncHour(TruncBase):
kind = "hour"
class TruncMinute(TruncBase):
kind = "minute"
class TruncSecond(TruncBase):
kind = "second"
DateTimeField.register_lookup(TruncDate)
DateTimeField.register_lookup(TruncTime)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/functions/datetime.py
|
Python
|
mit
| 13,658 |
import math
from django.db.models.expressions import Func, Value
from django.db.models.fields import FloatField, IntegerField
from django.db.models.functions import Cast
from django.db.models.functions.mixins import (
FixDecimalInputMixin,
NumericOutputFieldMixin,
)
from django.db.models.lookups import Transform
class Abs(Transform):
function = "ABS"
lookup_name = "abs"
class ACos(NumericOutputFieldMixin, Transform):
function = "ACOS"
lookup_name = "acos"
class ASin(NumericOutputFieldMixin, Transform):
function = "ASIN"
lookup_name = "asin"
class ATan(NumericOutputFieldMixin, Transform):
function = "ATAN"
lookup_name = "atan"
class ATan2(NumericOutputFieldMixin, Func):
function = "ATAN2"
arity = 2
def as_sqlite(self, compiler, connection, **extra_context):
if not getattr(
connection.ops, "spatialite", False
) or connection.ops.spatial_version >= (5, 0, 0):
return self.as_sql(compiler, connection)
# This function is usually ATan2(y, x), returning the inverse tangent
# of y / x, but it's ATan2(x, y) on SpatiaLite < 5.0.0.
# Cast integers to float to avoid inconsistent/buggy behavior if the
# arguments are mixed between integer and float or decimal.
# https://www.gaia-gis.it/fossil/libspatialite/tktview?name=0f72cca3a2
clone = self.copy()
clone.set_source_expressions(
[
Cast(expression, FloatField())
if isinstance(expression.output_field, IntegerField)
else expression
for expression in self.get_source_expressions()[::-1]
]
)
return clone.as_sql(compiler, connection, **extra_context)
class Ceil(Transform):
function = "CEILING"
lookup_name = "ceil"
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="CEIL", **extra_context)
class Cos(NumericOutputFieldMixin, Transform):
function = "COS"
lookup_name = "cos"
class Cot(NumericOutputFieldMixin, Transform):
function = "COT"
lookup_name = "cot"
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection, template="(1 / TAN(%(expressions)s))", **extra_context
)
class Degrees(NumericOutputFieldMixin, Transform):
function = "DEGREES"
lookup_name = "degrees"
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template="((%%(expressions)s) * 180 / %s)" % math.pi,
**extra_context,
)
class Exp(NumericOutputFieldMixin, Transform):
function = "EXP"
lookup_name = "exp"
class Floor(Transform):
function = "FLOOR"
lookup_name = "floor"
class Ln(NumericOutputFieldMixin, Transform):
function = "LN"
lookup_name = "ln"
class Log(FixDecimalInputMixin, NumericOutputFieldMixin, Func):
function = "LOG"
arity = 2
def as_sqlite(self, compiler, connection, **extra_context):
if not getattr(connection.ops, "spatialite", False):
return self.as_sql(compiler, connection)
# This function is usually Log(b, x) returning the logarithm of x to
# the base b, but on SpatiaLite it's Log(x, b).
clone = self.copy()
clone.set_source_expressions(self.get_source_expressions()[::-1])
return clone.as_sql(compiler, connection, **extra_context)
class Mod(FixDecimalInputMixin, NumericOutputFieldMixin, Func):
function = "MOD"
arity = 2
class Pi(NumericOutputFieldMixin, Func):
function = "PI"
arity = 0
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection, template=str(math.pi), **extra_context
)
class Power(NumericOutputFieldMixin, Func):
function = "POWER"
arity = 2
class Radians(NumericOutputFieldMixin, Transform):
function = "RADIANS"
lookup_name = "radians"
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template="((%%(expressions)s) * %s / 180)" % math.pi,
**extra_context,
)
class Random(NumericOutputFieldMixin, Func):
function = "RANDOM"
arity = 0
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="RAND", **extra_context)
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection, function="DBMS_RANDOM.VALUE", **extra_context
)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="RAND", **extra_context)
def get_group_by_cols(self):
return []
class Round(FixDecimalInputMixin, Transform):
function = "ROUND"
lookup_name = "round"
arity = None # Override Transform's arity=1 to enable passing precision.
def __init__(self, expression, precision=0, **extra):
super().__init__(expression, precision, **extra)
def as_sqlite(self, compiler, connection, **extra_context):
precision = self.get_source_expressions()[1]
if isinstance(precision, Value) and precision.value < 0:
raise ValueError("SQLite does not support negative precision.")
return super().as_sqlite(compiler, connection, **extra_context)
def _resolve_output_field(self):
source = self.get_source_expressions()[0]
return source.output_field
class Sign(Transform):
function = "SIGN"
lookup_name = "sign"
class Sin(NumericOutputFieldMixin, Transform):
function = "SIN"
lookup_name = "sin"
class Sqrt(NumericOutputFieldMixin, Transform):
function = "SQRT"
lookup_name = "sqrt"
class Tan(NumericOutputFieldMixin, Transform):
function = "TAN"
lookup_name = "tan"
|
castiel248/Convert
|
Lib/site-packages/django/db/models/functions/math.py
|
Python
|
mit
| 6,092 |
import sys
from django.db.models.fields import DecimalField, FloatField, IntegerField
from django.db.models.functions import Cast
class FixDecimalInputMixin:
def as_postgresql(self, compiler, connection, **extra_context):
# Cast FloatField to DecimalField as PostgreSQL doesn't support the
# following function signatures:
# - LOG(double, double)
# - MOD(double, double)
output_field = DecimalField(decimal_places=sys.float_info.dig, max_digits=1000)
clone = self.copy()
clone.set_source_expressions(
[
Cast(expression, output_field)
if isinstance(expression.output_field, FloatField)
else expression
for expression in self.get_source_expressions()
]
)
return clone.as_sql(compiler, connection, **extra_context)
class FixDurationInputMixin:
def as_mysql(self, compiler, connection, **extra_context):
sql, params = super().as_sql(compiler, connection, **extra_context)
if self.output_field.get_internal_type() == "DurationField":
sql = "CAST(%s AS SIGNED)" % sql
return sql, params
def as_oracle(self, compiler, connection, **extra_context):
if self.output_field.get_internal_type() == "DurationField":
expression = self.get_source_expressions()[0]
options = self._get_repr_options()
from django.db.backends.oracle.functions import (
IntervalToSeconds,
SecondsToInterval,
)
return compiler.compile(
SecondsToInterval(
self.__class__(IntervalToSeconds(expression), **options)
)
)
return super().as_sql(compiler, connection, **extra_context)
class NumericOutputFieldMixin:
def _resolve_output_field(self):
source_fields = self.get_source_fields()
if any(isinstance(s, DecimalField) for s in source_fields):
return DecimalField()
if any(isinstance(s, IntegerField) for s in source_fields):
return FloatField()
return super()._resolve_output_field() if source_fields else FloatField()
|
castiel248/Convert
|
Lib/site-packages/django/db/models/functions/mixins.py
|
Python
|
mit
| 2,229 |
from django.db import NotSupportedError
from django.db.models.expressions import Func, Value
from django.db.models.fields import CharField, IntegerField, TextField
from django.db.models.functions import Cast, Coalesce
from django.db.models.lookups import Transform
class MySQLSHA2Mixin:
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template="SHA2(%%(expressions)s, %s)" % self.function[3:],
**extra_context,
)
class OracleHashMixin:
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template=(
"LOWER(RAWTOHEX(STANDARD_HASH(UTL_I18N.STRING_TO_RAW("
"%(expressions)s, 'AL32UTF8'), '%(function)s')))"
),
**extra_context,
)
class PostgreSQLSHAMixin:
def as_postgresql(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template="ENCODE(DIGEST(%(expressions)s, '%(function)s'), 'hex')",
function=self.function.lower(),
**extra_context,
)
class Chr(Transform):
function = "CHR"
lookup_name = "chr"
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
function="CHAR",
template="%(function)s(%(expressions)s USING utf16)",
**extra_context,
)
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template="%(function)s(%(expressions)s USING NCHAR_CS)",
**extra_context,
)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="CHAR", **extra_context)
class ConcatPair(Func):
"""
Concatenate two arguments together. This is used by `Concat` because not
all backend databases support more than two arguments.
"""
function = "CONCAT"
def as_sqlite(self, compiler, connection, **extra_context):
coalesced = self.coalesce()
return super(ConcatPair, coalesced).as_sql(
compiler,
connection,
template="%(expressions)s",
arg_joiner=" || ",
**extra_context,
)
def as_postgresql(self, compiler, connection, **extra_context):
copy = self.copy()
copy.set_source_expressions(
[
Cast(expression, TextField())
for expression in copy.get_source_expressions()
]
)
return super(ConcatPair, copy).as_sql(
compiler,
connection,
**extra_context,
)
def as_mysql(self, compiler, connection, **extra_context):
# Use CONCAT_WS with an empty separator so that NULLs are ignored.
return super().as_sql(
compiler,
connection,
function="CONCAT_WS",
template="%(function)s('', %(expressions)s)",
**extra_context,
)
def coalesce(self):
# null on either side results in null for expression, wrap with coalesce
c = self.copy()
c.set_source_expressions(
[
Coalesce(expression, Value(""))
for expression in c.get_source_expressions()
]
)
return c
class Concat(Func):
"""
Concatenate text fields together. Backends that result in an entire
null expression when any arguments are null will wrap each argument in
coalesce functions to ensure a non-null result.
"""
function = None
template = "%(expressions)s"
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError("Concat must take at least two expressions")
paired = self._paired(expressions)
super().__init__(paired, **extra)
def _paired(self, expressions):
# wrap pairs of expressions in successive concat functions
# exp = [a, b, c, d]
# -> ConcatPair(a, ConcatPair(b, ConcatPair(c, d))))
if len(expressions) == 2:
return ConcatPair(*expressions)
return ConcatPair(expressions[0], self._paired(expressions[1:]))
class Left(Func):
function = "LEFT"
arity = 2
output_field = CharField()
def __init__(self, expression, length, **extra):
"""
expression: the name of a field, or an expression returning a string
length: the number of characters to return from the start of the string
"""
if not hasattr(length, "resolve_expression"):
if length < 1:
raise ValueError("'length' must be greater than 0.")
super().__init__(expression, length, **extra)
def get_substr(self):
return Substr(self.source_expressions[0], Value(1), self.source_expressions[1])
def as_oracle(self, compiler, connection, **extra_context):
return self.get_substr().as_oracle(compiler, connection, **extra_context)
def as_sqlite(self, compiler, connection, **extra_context):
return self.get_substr().as_sqlite(compiler, connection, **extra_context)
class Length(Transform):
"""Return the number of characters in the expression."""
function = "LENGTH"
lookup_name = "length"
output_field = IntegerField()
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection, function="CHAR_LENGTH", **extra_context
)
class Lower(Transform):
function = "LOWER"
lookup_name = "lower"
class LPad(Func):
function = "LPAD"
output_field = CharField()
def __init__(self, expression, length, fill_text=Value(" "), **extra):
if (
not hasattr(length, "resolve_expression")
and length is not None
and length < 0
):
raise ValueError("'length' must be greater or equal to 0.")
super().__init__(expression, length, fill_text, **extra)
class LTrim(Transform):
function = "LTRIM"
lookup_name = "ltrim"
class MD5(OracleHashMixin, Transform):
function = "MD5"
lookup_name = "md5"
class Ord(Transform):
function = "ASCII"
lookup_name = "ord"
output_field = IntegerField()
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="ORD", **extra_context)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="UNICODE", **extra_context)
class Repeat(Func):
function = "REPEAT"
output_field = CharField()
def __init__(self, expression, number, **extra):
if (
not hasattr(number, "resolve_expression")
and number is not None
and number < 0
):
raise ValueError("'number' must be greater or equal to 0.")
super().__init__(expression, number, **extra)
def as_oracle(self, compiler, connection, **extra_context):
expression, number = self.source_expressions
length = None if number is None else Length(expression) * number
rpad = RPad(expression, length, expression)
return rpad.as_sql(compiler, connection, **extra_context)
class Replace(Func):
function = "REPLACE"
def __init__(self, expression, text, replacement=Value(""), **extra):
super().__init__(expression, text, replacement, **extra)
class Reverse(Transform):
function = "REVERSE"
lookup_name = "reverse"
def as_oracle(self, compiler, connection, **extra_context):
# REVERSE in Oracle is undocumented and doesn't support multi-byte
# strings. Use a special subquery instead.
return super().as_sql(
compiler,
connection,
template=(
"(SELECT LISTAGG(s) WITHIN GROUP (ORDER BY n DESC) FROM "
"(SELECT LEVEL n, SUBSTR(%(expressions)s, LEVEL, 1) s "
"FROM DUAL CONNECT BY LEVEL <= LENGTH(%(expressions)s)) "
"GROUP BY %(expressions)s)"
),
**extra_context,
)
class Right(Left):
function = "RIGHT"
def get_substr(self):
return Substr(
self.source_expressions[0], self.source_expressions[1] * Value(-1)
)
class RPad(LPad):
function = "RPAD"
class RTrim(Transform):
function = "RTRIM"
lookup_name = "rtrim"
class SHA1(OracleHashMixin, PostgreSQLSHAMixin, Transform):
function = "SHA1"
lookup_name = "sha1"
class SHA224(MySQLSHA2Mixin, PostgreSQLSHAMixin, Transform):
function = "SHA224"
lookup_name = "sha224"
def as_oracle(self, compiler, connection, **extra_context):
raise NotSupportedError("SHA224 is not supported on Oracle.")
class SHA256(MySQLSHA2Mixin, OracleHashMixin, PostgreSQLSHAMixin, Transform):
function = "SHA256"
lookup_name = "sha256"
class SHA384(MySQLSHA2Mixin, OracleHashMixin, PostgreSQLSHAMixin, Transform):
function = "SHA384"
lookup_name = "sha384"
class SHA512(MySQLSHA2Mixin, OracleHashMixin, PostgreSQLSHAMixin, Transform):
function = "SHA512"
lookup_name = "sha512"
class StrIndex(Func):
"""
Return a positive integer corresponding to the 1-indexed position of the
first occurrence of a substring inside another string, or 0 if the
substring is not found.
"""
function = "INSTR"
arity = 2
output_field = IntegerField()
def as_postgresql(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="STRPOS", **extra_context)
class Substr(Func):
function = "SUBSTRING"
output_field = CharField()
def __init__(self, expression, pos, length=None, **extra):
"""
expression: the name of a field, or an expression returning a string
pos: an integer > 0, or an expression returning an integer
length: an optional number of characters to return
"""
if not hasattr(pos, "resolve_expression"):
if pos < 1:
raise ValueError("'pos' must be greater than 0")
expressions = [expression, pos]
if length is not None:
expressions.append(length)
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="SUBSTR", **extra_context)
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function="SUBSTR", **extra_context)
class Trim(Transform):
function = "TRIM"
lookup_name = "trim"
class Upper(Transform):
function = "UPPER"
lookup_name = "upper"
|
castiel248/Convert
|
Lib/site-packages/django/db/models/functions/text.py
|
Python
|
mit
| 11,035 |
from django.db.models.expressions import Func
from django.db.models.fields import FloatField, IntegerField
__all__ = [
"CumeDist",
"DenseRank",
"FirstValue",
"Lag",
"LastValue",
"Lead",
"NthValue",
"Ntile",
"PercentRank",
"Rank",
"RowNumber",
]
class CumeDist(Func):
function = "CUME_DIST"
output_field = FloatField()
window_compatible = True
class DenseRank(Func):
function = "DENSE_RANK"
output_field = IntegerField()
window_compatible = True
class FirstValue(Func):
arity = 1
function = "FIRST_VALUE"
window_compatible = True
class LagLeadFunction(Func):
window_compatible = True
def __init__(self, expression, offset=1, default=None, **extra):
if expression is None:
raise ValueError(
"%s requires a non-null source expression." % self.__class__.__name__
)
if offset is None or offset <= 0:
raise ValueError(
"%s requires a positive integer for the offset."
% self.__class__.__name__
)
args = (expression, offset)
if default is not None:
args += (default,)
super().__init__(*args, **extra)
def _resolve_output_field(self):
sources = self.get_source_expressions()
return sources[0].output_field
class Lag(LagLeadFunction):
function = "LAG"
class LastValue(Func):
arity = 1
function = "LAST_VALUE"
window_compatible = True
class Lead(LagLeadFunction):
function = "LEAD"
class NthValue(Func):
function = "NTH_VALUE"
window_compatible = True
def __init__(self, expression, nth=1, **extra):
if expression is None:
raise ValueError(
"%s requires a non-null source expression." % self.__class__.__name__
)
if nth is None or nth <= 0:
raise ValueError(
"%s requires a positive integer as for nth." % self.__class__.__name__
)
super().__init__(expression, nth, **extra)
def _resolve_output_field(self):
sources = self.get_source_expressions()
return sources[0].output_field
class Ntile(Func):
function = "NTILE"
output_field = IntegerField()
window_compatible = True
def __init__(self, num_buckets=1, **extra):
if num_buckets <= 0:
raise ValueError("num_buckets must be greater than 0.")
super().__init__(num_buckets, **extra)
class PercentRank(Func):
function = "PERCENT_RANK"
output_field = FloatField()
window_compatible = True
class Rank(Func):
function = "RANK"
output_field = IntegerField()
window_compatible = True
class RowNumber(Func):
function = "ROW_NUMBER"
output_field = IntegerField()
window_compatible = True
|
castiel248/Convert
|
Lib/site-packages/django/db/models/functions/window.py
|
Python
|
mit
| 2,841 |
from django.db.backends.utils import names_digest, split_identifier
from django.db.models.expressions import Col, ExpressionList, F, Func, OrderBy
from django.db.models.functions import Collate
from django.db.models.query_utils import Q
from django.db.models.sql import Query
from django.utils.functional import partition
__all__ = ["Index"]
class Index:
suffix = "idx"
# The max length of the name of the index (restricted to 30 for
# cross-database compatibility with Oracle)
max_name_length = 30
def __init__(
self,
*expressions,
fields=(),
name=None,
db_tablespace=None,
opclasses=(),
condition=None,
include=None,
):
if opclasses and not name:
raise ValueError("An index must be named to use opclasses.")
if not isinstance(condition, (type(None), Q)):
raise ValueError("Index.condition must be a Q instance.")
if condition and not name:
raise ValueError("An index must be named to use condition.")
if not isinstance(fields, (list, tuple)):
raise ValueError("Index.fields must be a list or tuple.")
if not isinstance(opclasses, (list, tuple)):
raise ValueError("Index.opclasses must be a list or tuple.")
if not expressions and not fields:
raise ValueError(
"At least one field or expression is required to define an index."
)
if expressions and fields:
raise ValueError(
"Index.fields and expressions are mutually exclusive.",
)
if expressions and not name:
raise ValueError("An index must be named to use expressions.")
if expressions and opclasses:
raise ValueError(
"Index.opclasses cannot be used with expressions. Use "
"django.contrib.postgres.indexes.OpClass() instead."
)
if opclasses and len(fields) != len(opclasses):
raise ValueError(
"Index.fields and Index.opclasses must have the same number of "
"elements."
)
if fields and not all(isinstance(field, str) for field in fields):
raise ValueError("Index.fields must contain only strings with field names.")
if include and not name:
raise ValueError("A covering index must be named.")
if not isinstance(include, (type(None), list, tuple)):
raise ValueError("Index.include must be a list or tuple.")
self.fields = list(fields)
# A list of 2-tuple with the field name and ordering ('' or 'DESC').
self.fields_orders = [
(field_name[1:], "DESC") if field_name.startswith("-") else (field_name, "")
for field_name in self.fields
]
self.name = name or ""
self.db_tablespace = db_tablespace
self.opclasses = opclasses
self.condition = condition
self.include = tuple(include) if include else ()
self.expressions = tuple(
F(expression) if isinstance(expression, str) else expression
for expression in expressions
)
@property
def contains_expressions(self):
return bool(self.expressions)
def _get_condition_sql(self, model, schema_editor):
if self.condition is None:
return None
query = Query(model=model, alias_cols=False)
where = query.build_where(self.condition)
compiler = query.get_compiler(connection=schema_editor.connection)
sql, params = where.as_sql(compiler, schema_editor.connection)
return sql % tuple(schema_editor.quote_value(p) for p in params)
def create_sql(self, model, schema_editor, using="", **kwargs):
include = [
model._meta.get_field(field_name).column for field_name in self.include
]
condition = self._get_condition_sql(model, schema_editor)
if self.expressions:
index_expressions = []
for expression in self.expressions:
index_expression = IndexExpression(expression)
index_expression.set_wrapper_classes(schema_editor.connection)
index_expressions.append(index_expression)
expressions = ExpressionList(*index_expressions).resolve_expression(
Query(model, alias_cols=False),
)
fields = None
col_suffixes = None
else:
fields = [
model._meta.get_field(field_name)
for field_name, _ in self.fields_orders
]
if schema_editor.connection.features.supports_index_column_ordering:
col_suffixes = [order[1] for order in self.fields_orders]
else:
col_suffixes = [""] * len(self.fields_orders)
expressions = None
return schema_editor._create_index_sql(
model,
fields=fields,
name=self.name,
using=using,
db_tablespace=self.db_tablespace,
col_suffixes=col_suffixes,
opclasses=self.opclasses,
condition=condition,
include=include,
expressions=expressions,
**kwargs,
)
def remove_sql(self, model, schema_editor, **kwargs):
return schema_editor._delete_index_sql(model, self.name, **kwargs)
def deconstruct(self):
path = "%s.%s" % (self.__class__.__module__, self.__class__.__name__)
path = path.replace("django.db.models.indexes", "django.db.models")
kwargs = {"name": self.name}
if self.fields:
kwargs["fields"] = self.fields
if self.db_tablespace is not None:
kwargs["db_tablespace"] = self.db_tablespace
if self.opclasses:
kwargs["opclasses"] = self.opclasses
if self.condition:
kwargs["condition"] = self.condition
if self.include:
kwargs["include"] = self.include
return (path, self.expressions, kwargs)
def clone(self):
"""Create a copy of this Index."""
_, args, kwargs = self.deconstruct()
return self.__class__(*args, **kwargs)
def set_name_with_model(self, model):
"""
Generate a unique name for the index.
The name is divided into 3 parts - table name (12 chars), field name
(8 chars) and unique hash + suffix (10 chars). Each part is made to
fit its size by truncating the excess length.
"""
_, table_name = split_identifier(model._meta.db_table)
column_names = [
model._meta.get_field(field_name).column
for field_name, order in self.fields_orders
]
column_names_with_order = [
(("-%s" if order else "%s") % column_name)
for column_name, (field_name, order) in zip(
column_names, self.fields_orders
)
]
# The length of the parts of the name is based on the default max
# length of 30 characters.
hash_data = [table_name] + column_names_with_order + [self.suffix]
self.name = "%s_%s_%s" % (
table_name[:11],
column_names[0][:7],
"%s_%s" % (names_digest(*hash_data, length=6), self.suffix),
)
if len(self.name) > self.max_name_length:
raise ValueError(
"Index too long for multiple database support. Is self.suffix "
"longer than 3 characters?"
)
if self.name[0] == "_" or self.name[0].isdigit():
self.name = "D%s" % self.name[1:]
def __repr__(self):
return "<%s:%s%s%s%s%s%s%s>" % (
self.__class__.__qualname__,
"" if not self.fields else " fields=%s" % repr(self.fields),
"" if not self.expressions else " expressions=%s" % repr(self.expressions),
"" if not self.name else " name=%s" % repr(self.name),
""
if self.db_tablespace is None
else " db_tablespace=%s" % repr(self.db_tablespace),
"" if self.condition is None else " condition=%s" % self.condition,
"" if not self.include else " include=%s" % repr(self.include),
"" if not self.opclasses else " opclasses=%s" % repr(self.opclasses),
)
def __eq__(self, other):
if self.__class__ == other.__class__:
return self.deconstruct() == other.deconstruct()
return NotImplemented
class IndexExpression(Func):
"""Order and wrap expressions for CREATE INDEX statements."""
template = "%(expressions)s"
wrapper_classes = (OrderBy, Collate)
def set_wrapper_classes(self, connection=None):
# Some databases (e.g. MySQL) treats COLLATE as an indexed expression.
if connection and connection.features.collate_as_index_expression:
self.wrapper_classes = tuple(
[
wrapper_cls
for wrapper_cls in self.wrapper_classes
if wrapper_cls is not Collate
]
)
@classmethod
def register_wrappers(cls, *wrapper_classes):
cls.wrapper_classes = wrapper_classes
def resolve_expression(
self,
query=None,
allow_joins=True,
reuse=None,
summarize=False,
for_save=False,
):
expressions = list(self.flatten())
# Split expressions and wrappers.
index_expressions, wrappers = partition(
lambda e: isinstance(e, self.wrapper_classes),
expressions,
)
wrapper_types = [type(wrapper) for wrapper in wrappers]
if len(wrapper_types) != len(set(wrapper_types)):
raise ValueError(
"Multiple references to %s can't be used in an indexed "
"expression."
% ", ".join(
[wrapper_cls.__qualname__ for wrapper_cls in self.wrapper_classes]
)
)
if expressions[1 : len(wrappers) + 1] != wrappers:
raise ValueError(
"%s must be topmost expressions in an indexed expression."
% ", ".join(
[wrapper_cls.__qualname__ for wrapper_cls in self.wrapper_classes]
)
)
# Wrap expressions in parentheses if they are not column references.
root_expression = index_expressions[1]
resolve_root_expression = root_expression.resolve_expression(
query,
allow_joins,
reuse,
summarize,
for_save,
)
if not isinstance(resolve_root_expression, Col):
root_expression = Func(root_expression, template="(%(expressions)s)")
if wrappers:
# Order wrappers and set their expressions.
wrappers = sorted(
wrappers,
key=lambda w: self.wrapper_classes.index(type(w)),
)
wrappers = [wrapper.copy() for wrapper in wrappers]
for i, wrapper in enumerate(wrappers[:-1]):
wrapper.set_source_expressions([wrappers[i + 1]])
# Set the root expression on the deepest wrapper.
wrappers[-1].set_source_expressions([root_expression])
self.set_source_expressions([wrappers[0]])
else:
# Use the root expression, if there are no wrappers.
self.set_source_expressions([root_expression])
return super().resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
def as_sqlite(self, compiler, connection, **extra_context):
# Casting to numeric is unnecessary.
return self.as_sql(compiler, connection, **extra_context)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/indexes.py
|
Python
|
mit
| 11,871 |
import itertools
import math
from django.core.exceptions import EmptyResultSet
from django.db.models.expressions import Case, Expression, Func, Value, When
from django.db.models.fields import (
BooleanField,
CharField,
DateTimeField,
Field,
IntegerField,
UUIDField,
)
from django.db.models.query_utils import RegisterLookupMixin
from django.utils.datastructures import OrderedSet
from django.utils.functional import cached_property
from django.utils.hashable import make_hashable
class Lookup(Expression):
lookup_name = None
prepare_rhs = True
can_use_none_as_rhs = False
def __init__(self, lhs, rhs):
self.lhs, self.rhs = lhs, rhs
self.rhs = self.get_prep_lookup()
self.lhs = self.get_prep_lhs()
if hasattr(self.lhs, "get_bilateral_transforms"):
bilateral_transforms = self.lhs.get_bilateral_transforms()
else:
bilateral_transforms = []
if bilateral_transforms:
# Warn the user as soon as possible if they are trying to apply
# a bilateral transformation on a nested QuerySet: that won't work.
from django.db.models.sql.query import Query # avoid circular import
if isinstance(rhs, Query):
raise NotImplementedError(
"Bilateral transformations on nested querysets are not implemented."
)
self.bilateral_transforms = bilateral_transforms
def apply_bilateral_transforms(self, value):
for transform in self.bilateral_transforms:
value = transform(value)
return value
def __repr__(self):
return f"{self.__class__.__name__}({self.lhs!r}, {self.rhs!r})"
def batch_process_rhs(self, compiler, connection, rhs=None):
if rhs is None:
rhs = self.rhs
if self.bilateral_transforms:
sqls, sqls_params = [], []
for p in rhs:
value = Value(p, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
sql, sql_params = compiler.compile(value)
sqls.append(sql)
sqls_params.extend(sql_params)
else:
_, params = self.get_db_prep_lookup(rhs, connection)
sqls, sqls_params = ["%s"] * len(params), params
return sqls, sqls_params
def get_source_expressions(self):
if self.rhs_is_direct_value():
return [self.lhs]
return [self.lhs, self.rhs]
def set_source_expressions(self, new_exprs):
if len(new_exprs) == 1:
self.lhs = new_exprs[0]
else:
self.lhs, self.rhs = new_exprs
def get_prep_lookup(self):
if not self.prepare_rhs or hasattr(self.rhs, "resolve_expression"):
return self.rhs
if hasattr(self.lhs, "output_field"):
if hasattr(self.lhs.output_field, "get_prep_value"):
return self.lhs.output_field.get_prep_value(self.rhs)
elif self.rhs_is_direct_value():
return Value(self.rhs)
return self.rhs
def get_prep_lhs(self):
if hasattr(self.lhs, "resolve_expression"):
return self.lhs
return Value(self.lhs)
def get_db_prep_lookup(self, value, connection):
return ("%s", [value])
def process_lhs(self, compiler, connection, lhs=None):
lhs = lhs or self.lhs
if hasattr(lhs, "resolve_expression"):
lhs = lhs.resolve_expression(compiler.query)
sql, params = compiler.compile(lhs)
if isinstance(lhs, Lookup):
# Wrapped in parentheses to respect operator precedence.
sql = f"({sql})"
return sql, params
def process_rhs(self, compiler, connection):
value = self.rhs
if self.bilateral_transforms:
if self.rhs_is_direct_value():
# Do not call get_db_prep_lookup here as the value will be
# transformed before being used for lookup
value = Value(value, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
if hasattr(value, "as_sql"):
sql, params = compiler.compile(value)
# Ensure expression is wrapped in parentheses to respect operator
# precedence but avoid double wrapping as it can be misinterpreted
# on some backends (e.g. subqueries on SQLite).
if sql and sql[0] != "(":
sql = "(%s)" % sql
return sql, params
else:
return self.get_db_prep_lookup(value, connection)
def rhs_is_direct_value(self):
return not hasattr(self.rhs, "as_sql")
def get_group_by_cols(self):
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
def as_oracle(self, compiler, connection):
# Oracle doesn't allow EXISTS() and filters to be compared to another
# expression unless they're wrapped in a CASE WHEN.
wrapped = False
exprs = []
for expr in (self.lhs, self.rhs):
if connection.ops.conditional_expression_supported_in_where_clause(expr):
expr = Case(When(expr, then=True), default=False)
wrapped = True
exprs.append(expr)
lookup = type(self)(*exprs) if wrapped else self
return lookup.as_sql(compiler, connection)
@cached_property
def output_field(self):
return BooleanField()
@property
def identity(self):
return self.__class__, self.lhs, self.rhs
def __eq__(self, other):
if not isinstance(other, Lookup):
return NotImplemented
return self.identity == other.identity
def __hash__(self):
return hash(make_hashable(self.identity))
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
c = self.copy()
c.is_summary = summarize
c.lhs = self.lhs.resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
if hasattr(self.rhs, "resolve_expression"):
c.rhs = self.rhs.resolve_expression(
query, allow_joins, reuse, summarize, for_save
)
return c
def select_format(self, compiler, sql, params):
# Wrap filters with a CASE WHEN expression if a database backend
# (e.g. Oracle) doesn't support boolean expression in SELECT or GROUP
# BY list.
if not compiler.connection.features.supports_boolean_expr_in_select_clause:
sql = f"CASE WHEN {sql} THEN 1 ELSE 0 END"
return sql, params
class Transform(RegisterLookupMixin, Func):
"""
RegisterLookupMixin() is first so that get_lookup() and get_transform()
first examine self and then check output_field.
"""
bilateral = False
arity = 1
@property
def lhs(self):
return self.get_source_expressions()[0]
def get_bilateral_transforms(self):
if hasattr(self.lhs, "get_bilateral_transforms"):
bilateral_transforms = self.lhs.get_bilateral_transforms()
else:
bilateral_transforms = []
if self.bilateral:
bilateral_transforms.append(self.__class__)
return bilateral_transforms
class BuiltinLookup(Lookup):
def process_lhs(self, compiler, connection, lhs=None):
lhs_sql, params = super().process_lhs(compiler, connection, lhs)
field_internal_type = self.lhs.output_field.get_internal_type()
db_type = self.lhs.output_field.db_type(connection=connection)
lhs_sql = connection.ops.field_cast_sql(db_type, field_internal_type) % lhs_sql
lhs_sql = (
connection.ops.lookup_cast(self.lookup_name, field_internal_type) % lhs_sql
)
return lhs_sql, list(params)
def as_sql(self, compiler, connection):
lhs_sql, params = self.process_lhs(compiler, connection)
rhs_sql, rhs_params = self.process_rhs(compiler, connection)
params.extend(rhs_params)
rhs_sql = self.get_rhs_op(connection, rhs_sql)
return "%s %s" % (lhs_sql, rhs_sql), params
def get_rhs_op(self, connection, rhs):
return connection.operators[self.lookup_name] % rhs
class FieldGetDbPrepValueMixin:
"""
Some lookups require Field.get_db_prep_value() to be called on their
inputs.
"""
get_db_prep_lookup_value_is_iterable = False
def get_db_prep_lookup(self, value, connection):
# For relational fields, use the 'target_field' attribute of the
# output_field.
field = getattr(self.lhs.output_field, "target_field", None)
get_db_prep_value = (
getattr(field, "get_db_prep_value", None)
or self.lhs.output_field.get_db_prep_value
)
return (
"%s",
[get_db_prep_value(v, connection, prepared=True) for v in value]
if self.get_db_prep_lookup_value_is_iterable
else [get_db_prep_value(value, connection, prepared=True)],
)
class FieldGetDbPrepValueIterableMixin(FieldGetDbPrepValueMixin):
"""
Some lookups require Field.get_db_prep_value() to be called on each value
in an iterable.
"""
get_db_prep_lookup_value_is_iterable = True
def get_prep_lookup(self):
if hasattr(self.rhs, "resolve_expression"):
return self.rhs
prepared_values = []
for rhs_value in self.rhs:
if hasattr(rhs_value, "resolve_expression"):
# An expression will be handled by the database but can coexist
# alongside real values.
pass
elif self.prepare_rhs and hasattr(self.lhs.output_field, "get_prep_value"):
rhs_value = self.lhs.output_field.get_prep_value(rhs_value)
prepared_values.append(rhs_value)
return prepared_values
def process_rhs(self, compiler, connection):
if self.rhs_is_direct_value():
# rhs should be an iterable of values. Use batch_process_rhs()
# to prepare/transform those values.
return self.batch_process_rhs(compiler, connection)
else:
return super().process_rhs(compiler, connection)
def resolve_expression_parameter(self, compiler, connection, sql, param):
params = [param]
if hasattr(param, "resolve_expression"):
param = param.resolve_expression(compiler.query)
if hasattr(param, "as_sql"):
sql, params = compiler.compile(param)
return sql, params
def batch_process_rhs(self, compiler, connection, rhs=None):
pre_processed = super().batch_process_rhs(compiler, connection, rhs)
# The params list may contain expressions which compile to a
# sql/param pair. Zip them to get sql and param pairs that refer to the
# same argument and attempt to replace them with the result of
# compiling the param step.
sql, params = zip(
*(
self.resolve_expression_parameter(compiler, connection, sql, param)
for sql, param in zip(*pre_processed)
)
)
params = itertools.chain.from_iterable(params)
return sql, tuple(params)
class PostgresOperatorLookup(Lookup):
"""Lookup defined by operators on PostgreSQL."""
postgres_operator = None
def as_postgresql(self, compiler, connection):
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
params = tuple(lhs_params) + tuple(rhs_params)
return "%s %s %s" % (lhs, self.postgres_operator, rhs), params
@Field.register_lookup
class Exact(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = "exact"
def get_prep_lookup(self):
from django.db.models.sql.query import Query # avoid circular import
if isinstance(self.rhs, Query):
if self.rhs.has_limit_one():
if not self.rhs.has_select_fields:
self.rhs.clear_select_clause()
self.rhs.add_fields(["pk"])
else:
raise ValueError(
"The QuerySet value for an exact lookup must be limited to "
"one result using slicing."
)
return super().get_prep_lookup()
def as_sql(self, compiler, connection):
# Avoid comparison against direct rhs if lhs is a boolean value. That
# turns "boolfield__exact=True" into "WHERE boolean_field" instead of
# "WHERE boolean_field = True" when allowed.
if (
isinstance(self.rhs, bool)
and getattr(self.lhs, "conditional", False)
and connection.ops.conditional_expression_supported_in_where_clause(
self.lhs
)
):
lhs_sql, params = self.process_lhs(compiler, connection)
template = "%s" if self.rhs else "NOT %s"
return template % lhs_sql, params
return super().as_sql(compiler, connection)
@Field.register_lookup
class IExact(BuiltinLookup):
lookup_name = "iexact"
prepare_rhs = False
def process_rhs(self, qn, connection):
rhs, params = super().process_rhs(qn, connection)
if params:
params[0] = connection.ops.prep_for_iexact_query(params[0])
return rhs, params
@Field.register_lookup
class GreaterThan(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = "gt"
@Field.register_lookup
class GreaterThanOrEqual(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = "gte"
@Field.register_lookup
class LessThan(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = "lt"
@Field.register_lookup
class LessThanOrEqual(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = "lte"
class IntegerFieldFloatRounding:
"""
Allow floats to work as query values for IntegerField. Without this, the
decimal portion of the float would always be discarded.
"""
def get_prep_lookup(self):
if isinstance(self.rhs, float):
self.rhs = math.ceil(self.rhs)
return super().get_prep_lookup()
@IntegerField.register_lookup
class IntegerGreaterThanOrEqual(IntegerFieldFloatRounding, GreaterThanOrEqual):
pass
@IntegerField.register_lookup
class IntegerLessThan(IntegerFieldFloatRounding, LessThan):
pass
@Field.register_lookup
class In(FieldGetDbPrepValueIterableMixin, BuiltinLookup):
lookup_name = "in"
def get_prep_lookup(self):
from django.db.models.sql.query import Query # avoid circular import
if isinstance(self.rhs, Query):
self.rhs.clear_ordering(clear_default=True)
if not self.rhs.has_select_fields:
self.rhs.clear_select_clause()
self.rhs.add_fields(["pk"])
return super().get_prep_lookup()
def process_rhs(self, compiler, connection):
db_rhs = getattr(self.rhs, "_db", None)
if db_rhs is not None and db_rhs != connection.alias:
raise ValueError(
"Subqueries aren't allowed across different databases. Force "
"the inner query to be evaluated using `list(inner_query)`."
)
if self.rhs_is_direct_value():
# Remove None from the list as NULL is never equal to anything.
try:
rhs = OrderedSet(self.rhs)
rhs.discard(None)
except TypeError: # Unhashable items in self.rhs
rhs = [r for r in self.rhs if r is not None]
if not rhs:
raise EmptyResultSet
# rhs should be an iterable; use batch_process_rhs() to
# prepare/transform those values.
sqls, sqls_params = self.batch_process_rhs(compiler, connection, rhs)
placeholder = "(" + ", ".join(sqls) + ")"
return (placeholder, sqls_params)
return super().process_rhs(compiler, connection)
def get_rhs_op(self, connection, rhs):
return "IN %s" % rhs
def as_sql(self, compiler, connection):
max_in_list_size = connection.ops.max_in_list_size()
if (
self.rhs_is_direct_value()
and max_in_list_size
and len(self.rhs) > max_in_list_size
):
return self.split_parameter_list_as_sql(compiler, connection)
return super().as_sql(compiler, connection)
def split_parameter_list_as_sql(self, compiler, connection):
# This is a special case for databases which limit the number of
# elements which can appear in an 'IN' clause.
max_in_list_size = connection.ops.max_in_list_size()
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.batch_process_rhs(compiler, connection)
in_clause_elements = ["("]
params = []
for offset in range(0, len(rhs_params), max_in_list_size):
if offset > 0:
in_clause_elements.append(" OR ")
in_clause_elements.append("%s IN (" % lhs)
params.extend(lhs_params)
sqls = rhs[offset : offset + max_in_list_size]
sqls_params = rhs_params[offset : offset + max_in_list_size]
param_group = ", ".join(sqls)
in_clause_elements.append(param_group)
in_clause_elements.append(")")
params.extend(sqls_params)
in_clause_elements.append(")")
return "".join(in_clause_elements), params
class PatternLookup(BuiltinLookup):
param_pattern = "%%%s%%"
prepare_rhs = False
def get_rhs_op(self, connection, rhs):
# Assume we are in startswith. We need to produce SQL like:
# col LIKE %s, ['thevalue%']
# For python values we can (and should) do that directly in Python,
# but if the value is for example reference to other column, then
# we need to add the % pattern match to the lookup by something like
# col LIKE othercol || '%%'
# So, for Python values we don't need any special pattern, but for
# SQL reference values or SQL transformations we need the correct
# pattern added.
if hasattr(self.rhs, "as_sql") or self.bilateral_transforms:
pattern = connection.pattern_ops[self.lookup_name].format(
connection.pattern_esc
)
return pattern.format(rhs)
else:
return super().get_rhs_op(connection, rhs)
def process_rhs(self, qn, connection):
rhs, params = super().process_rhs(qn, connection)
if self.rhs_is_direct_value() and params and not self.bilateral_transforms:
params[0] = self.param_pattern % connection.ops.prep_for_like_query(
params[0]
)
return rhs, params
@Field.register_lookup
class Contains(PatternLookup):
lookup_name = "contains"
@Field.register_lookup
class IContains(Contains):
lookup_name = "icontains"
@Field.register_lookup
class StartsWith(PatternLookup):
lookup_name = "startswith"
param_pattern = "%s%%"
@Field.register_lookup
class IStartsWith(StartsWith):
lookup_name = "istartswith"
@Field.register_lookup
class EndsWith(PatternLookup):
lookup_name = "endswith"
param_pattern = "%%%s"
@Field.register_lookup
class IEndsWith(EndsWith):
lookup_name = "iendswith"
@Field.register_lookup
class Range(FieldGetDbPrepValueIterableMixin, BuiltinLookup):
lookup_name = "range"
def get_rhs_op(self, connection, rhs):
return "BETWEEN %s AND %s" % (rhs[0], rhs[1])
@Field.register_lookup
class IsNull(BuiltinLookup):
lookup_name = "isnull"
prepare_rhs = False
def as_sql(self, compiler, connection):
if not isinstance(self.rhs, bool):
raise ValueError(
"The QuerySet value for an isnull lookup must be True or False."
)
sql, params = self.process_lhs(compiler, connection)
if self.rhs:
return "%s IS NULL" % sql, params
else:
return "%s IS NOT NULL" % sql, params
@Field.register_lookup
class Regex(BuiltinLookup):
lookup_name = "regex"
prepare_rhs = False
def as_sql(self, compiler, connection):
if self.lookup_name in connection.operators:
return super().as_sql(compiler, connection)
else:
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
sql_template = connection.ops.regex_lookup(self.lookup_name)
return sql_template % (lhs, rhs), lhs_params + rhs_params
@Field.register_lookup
class IRegex(Regex):
lookup_name = "iregex"
class YearLookup(Lookup):
def year_lookup_bounds(self, connection, year):
from django.db.models.functions import ExtractIsoYear
iso_year = isinstance(self.lhs, ExtractIsoYear)
output_field = self.lhs.lhs.output_field
if isinstance(output_field, DateTimeField):
bounds = connection.ops.year_lookup_bounds_for_datetime_field(
year,
iso_year=iso_year,
)
else:
bounds = connection.ops.year_lookup_bounds_for_date_field(
year,
iso_year=iso_year,
)
return bounds
def as_sql(self, compiler, connection):
# Avoid the extract operation if the rhs is a direct value to allow
# indexes to be used.
if self.rhs_is_direct_value():
# Skip the extract part by directly using the originating field,
# that is self.lhs.lhs.
lhs_sql, params = self.process_lhs(compiler, connection, self.lhs.lhs)
rhs_sql, _ = self.process_rhs(compiler, connection)
rhs_sql = self.get_direct_rhs_sql(connection, rhs_sql)
start, finish = self.year_lookup_bounds(connection, self.rhs)
params.extend(self.get_bound_params(start, finish))
return "%s %s" % (lhs_sql, rhs_sql), params
return super().as_sql(compiler, connection)
def get_direct_rhs_sql(self, connection, rhs):
return connection.operators[self.lookup_name] % rhs
def get_bound_params(self, start, finish):
raise NotImplementedError(
"subclasses of YearLookup must provide a get_bound_params() method"
)
class YearExact(YearLookup, Exact):
def get_direct_rhs_sql(self, connection, rhs):
return "BETWEEN %s AND %s"
def get_bound_params(self, start, finish):
return (start, finish)
class YearGt(YearLookup, GreaterThan):
def get_bound_params(self, start, finish):
return (finish,)
class YearGte(YearLookup, GreaterThanOrEqual):
def get_bound_params(self, start, finish):
return (start,)
class YearLt(YearLookup, LessThan):
def get_bound_params(self, start, finish):
return (start,)
class YearLte(YearLookup, LessThanOrEqual):
def get_bound_params(self, start, finish):
return (finish,)
class UUIDTextMixin:
"""
Strip hyphens from a value when filtering a UUIDField on backends without
a native datatype for UUID.
"""
def process_rhs(self, qn, connection):
if not connection.features.has_native_uuid_field:
from django.db.models.functions import Replace
if self.rhs_is_direct_value():
self.rhs = Value(self.rhs)
self.rhs = Replace(
self.rhs, Value("-"), Value(""), output_field=CharField()
)
rhs, params = super().process_rhs(qn, connection)
return rhs, params
@UUIDField.register_lookup
class UUIDIExact(UUIDTextMixin, IExact):
pass
@UUIDField.register_lookup
class UUIDContains(UUIDTextMixin, Contains):
pass
@UUIDField.register_lookup
class UUIDIContains(UUIDTextMixin, IContains):
pass
@UUIDField.register_lookup
class UUIDStartsWith(UUIDTextMixin, StartsWith):
pass
@UUIDField.register_lookup
class UUIDIStartsWith(UUIDTextMixin, IStartsWith):
pass
@UUIDField.register_lookup
class UUIDEndsWith(UUIDTextMixin, EndsWith):
pass
@UUIDField.register_lookup
class UUIDIEndsWith(UUIDTextMixin, IEndsWith):
pass
|
castiel248/Convert
|
Lib/site-packages/django/db/models/lookups.py
|
Python
|
mit
| 24,608 |
import copy
import inspect
from functools import wraps
from importlib import import_module
from django.db import router
from django.db.models.query import QuerySet
class BaseManager:
# To retain order, track each time a Manager instance is created.
creation_counter = 0
# Set to True for the 'objects' managers that are automatically created.
auto_created = False
#: If set to True the manager will be serialized into migrations and will
#: thus be available in e.g. RunPython operations.
use_in_migrations = False
def __new__(cls, *args, **kwargs):
# Capture the arguments to make returning them trivial.
obj = super().__new__(cls)
obj._constructor_args = (args, kwargs)
return obj
def __init__(self):
super().__init__()
self._set_creation_counter()
self.model = None
self.name = None
self._db = None
self._hints = {}
def __str__(self):
"""Return "app_label.model_label.manager_name"."""
return "%s.%s" % (self.model._meta.label, self.name)
def __class_getitem__(cls, *args, **kwargs):
return cls
def deconstruct(self):
"""
Return a 5-tuple of the form (as_manager (True), manager_class,
queryset_class, args, kwargs).
Raise a ValueError if the manager is dynamically generated.
"""
qs_class = self._queryset_class
if getattr(self, "_built_with_as_manager", False):
# using MyQuerySet.as_manager()
return (
True, # as_manager
None, # manager_class
"%s.%s" % (qs_class.__module__, qs_class.__name__), # qs_class
None, # args
None, # kwargs
)
else:
module_name = self.__module__
name = self.__class__.__name__
# Make sure it's actually there and not an inner class
module = import_module(module_name)
if not hasattr(module, name):
raise ValueError(
"Could not find manager %s in %s.\n"
"Please note that you need to inherit from managers you "
"dynamically generated with 'from_queryset()'."
% (name, module_name)
)
return (
False, # as_manager
"%s.%s" % (module_name, name), # manager_class
None, # qs_class
self._constructor_args[0], # args
self._constructor_args[1], # kwargs
)
def check(self, **kwargs):
return []
@classmethod
def _get_queryset_methods(cls, queryset_class):
def create_method(name, method):
@wraps(method)
def manager_method(self, *args, **kwargs):
return getattr(self.get_queryset(), name)(*args, **kwargs)
return manager_method
new_methods = {}
for name, method in inspect.getmembers(
queryset_class, predicate=inspect.isfunction
):
# Only copy missing methods.
if hasattr(cls, name):
continue
# Only copy public methods or methods with the attribute
# queryset_only=False.
queryset_only = getattr(method, "queryset_only", None)
if queryset_only or (queryset_only is None and name.startswith("_")):
continue
# Copy the method onto the manager.
new_methods[name] = create_method(name, method)
return new_methods
@classmethod
def from_queryset(cls, queryset_class, class_name=None):
if class_name is None:
class_name = "%sFrom%s" % (cls.__name__, queryset_class.__name__)
return type(
class_name,
(cls,),
{
"_queryset_class": queryset_class,
**cls._get_queryset_methods(queryset_class),
},
)
def contribute_to_class(self, cls, name):
self.name = self.name or name
self.model = cls
setattr(cls, name, ManagerDescriptor(self))
cls._meta.add_manager(self)
def _set_creation_counter(self):
"""
Set the creation counter value for this instance and increment the
class-level copy.
"""
self.creation_counter = BaseManager.creation_counter
BaseManager.creation_counter += 1
def db_manager(self, using=None, hints=None):
obj = copy.copy(self)
obj._db = using or self._db
obj._hints = hints or self._hints
return obj
@property
def db(self):
return self._db or router.db_for_read(self.model, **self._hints)
#######################
# PROXIES TO QUERYSET #
#######################
def get_queryset(self):
"""
Return a new QuerySet object. Subclasses can override this method to
customize the behavior of the Manager.
"""
return self._queryset_class(model=self.model, using=self._db, hints=self._hints)
def all(self):
# We can't proxy this method through the `QuerySet` like we do for the
# rest of the `QuerySet` methods. This is because `QuerySet.all()`
# works by creating a "copy" of the current queryset and in making said
# copy, all the cached `prefetch_related` lookups are lost. See the
# implementation of `RelatedManager.get_queryset()` for a better
# understanding of how this comes into play.
return self.get_queryset()
def __eq__(self, other):
return (
isinstance(other, self.__class__)
and self._constructor_args == other._constructor_args
)
def __hash__(self):
return id(self)
class Manager(BaseManager.from_queryset(QuerySet)):
pass
class ManagerDescriptor:
def __init__(self, manager):
self.manager = manager
def __get__(self, instance, cls=None):
if instance is not None:
raise AttributeError(
"Manager isn't accessible via %s instances" % cls.__name__
)
if cls._meta.abstract:
raise AttributeError(
"Manager isn't available; %s is abstract" % (cls._meta.object_name,)
)
if cls._meta.swapped:
raise AttributeError(
"Manager isn't available; '%s' has been swapped for '%s'"
% (
cls._meta.label,
cls._meta.swapped,
)
)
return cls._meta.managers_map[self.manager.name]
class EmptyManager(Manager):
def __init__(self, model):
super().__init__()
self.model = model
def get_queryset(self):
return super().get_queryset().none()
|
castiel248/Convert
|
Lib/site-packages/django/db/models/manager.py
|
Python
|
mit
| 6,866 |
import bisect
import copy
import inspect
import warnings
from collections import defaultdict
from django.apps import apps
from django.conf import settings
from django.core.exceptions import FieldDoesNotExist, ImproperlyConfigured
from django.db import connections
from django.db.models import AutoField, Manager, OrderWrt, UniqueConstraint
from django.db.models.query_utils import PathInfo
from django.utils.datastructures import ImmutableList, OrderedSet
from django.utils.deprecation import RemovedInDjango51Warning
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from django.utils.text import camel_case_to_spaces, format_lazy
from django.utils.translation import override
PROXY_PARENTS = object()
EMPTY_RELATION_TREE = ()
IMMUTABLE_WARNING = (
"The return type of '%s' should never be mutated. If you want to manipulate this "
"list for your own use, make a copy first."
)
DEFAULT_NAMES = (
"verbose_name",
"verbose_name_plural",
"db_table",
"db_table_comment",
"ordering",
"unique_together",
"permissions",
"get_latest_by",
"order_with_respect_to",
"app_label",
"db_tablespace",
"abstract",
"managed",
"proxy",
"swappable",
"auto_created",
# Must be kept for backward compatibility with old migrations.
"index_together",
"apps",
"default_permissions",
"select_on_save",
"default_related_name",
"required_db_features",
"required_db_vendor",
"base_manager_name",
"default_manager_name",
"indexes",
"constraints",
)
def normalize_together(option_together):
"""
option_together can be either a tuple of tuples, or a single
tuple of two strings. Normalize it to a tuple of tuples, so that
calling code can uniformly expect that.
"""
try:
if not option_together:
return ()
if not isinstance(option_together, (tuple, list)):
raise TypeError
first_element = option_together[0]
if not isinstance(first_element, (tuple, list)):
option_together = (option_together,)
# Normalize everything to tuples
return tuple(tuple(ot) for ot in option_together)
except TypeError:
# If the value of option_together isn't valid, return it
# verbatim; this will be picked up by the check framework later.
return option_together
def make_immutable_fields_list(name, data):
return ImmutableList(data, warning=IMMUTABLE_WARNING % name)
class Options:
FORWARD_PROPERTIES = {
"fields",
"many_to_many",
"concrete_fields",
"local_concrete_fields",
"_non_pk_concrete_field_names",
"_forward_fields_map",
"managers",
"managers_map",
"base_manager",
"default_manager",
}
REVERSE_PROPERTIES = {"related_objects", "fields_map", "_relation_tree"}
default_apps = apps
def __init__(self, meta, app_label=None):
self._get_fields_cache = {}
self.local_fields = []
self.local_many_to_many = []
self.private_fields = []
self.local_managers = []
self.base_manager_name = None
self.default_manager_name = None
self.model_name = None
self.verbose_name = None
self.verbose_name_plural = None
self.db_table = ""
self.db_table_comment = ""
self.ordering = []
self._ordering_clash = False
self.indexes = []
self.constraints = []
self.unique_together = []
self.index_together = [] # RemovedInDjango51Warning.
self.select_on_save = False
self.default_permissions = ("add", "change", "delete", "view")
self.permissions = []
self.object_name = None
self.app_label = app_label
self.get_latest_by = None
self.order_with_respect_to = None
self.db_tablespace = settings.DEFAULT_TABLESPACE
self.required_db_features = []
self.required_db_vendor = None
self.meta = meta
self.pk = None
self.auto_field = None
self.abstract = False
self.managed = True
self.proxy = False
# For any class that is a proxy (including automatically created
# classes for deferred object loading), proxy_for_model tells us
# which class this model is proxying. Note that proxy_for_model
# can create a chain of proxy models. For non-proxy models, the
# variable is always None.
self.proxy_for_model = None
# For any non-abstract class, the concrete class is the model
# in the end of the proxy_for_model chain. In particular, for
# concrete models, the concrete_model is always the class itself.
self.concrete_model = None
self.swappable = None
self.parents = {}
self.auto_created = False
# List of all lookups defined in ForeignKey 'limit_choices_to' options
# from *other* models. Needed for some admin checks. Internal use only.
self.related_fkey_lookups = []
# A custom app registry to use, if you're making a separate model set.
self.apps = self.default_apps
self.default_related_name = None
@property
def label(self):
return "%s.%s" % (self.app_label, self.object_name)
@property
def label_lower(self):
return "%s.%s" % (self.app_label, self.model_name)
@property
def app_config(self):
# Don't go through get_app_config to avoid triggering imports.
return self.apps.app_configs.get(self.app_label)
def contribute_to_class(self, cls, name):
from django.db import connection
from django.db.backends.utils import truncate_name
cls._meta = self
self.model = cls
# First, construct the default values for these options.
self.object_name = cls.__name__
self.model_name = self.object_name.lower()
self.verbose_name = camel_case_to_spaces(self.object_name)
# Store the original user-defined values for each option,
# for use when serializing the model definition
self.original_attrs = {}
# Next, apply any overridden values from 'class Meta'.
if self.meta:
meta_attrs = self.meta.__dict__.copy()
for name in self.meta.__dict__:
# Ignore any private attributes that Django doesn't care about.
# NOTE: We can't modify a dictionary's contents while looping
# over it, so we loop over the *original* dictionary instead.
if name.startswith("_"):
del meta_attrs[name]
for attr_name in DEFAULT_NAMES:
if attr_name in meta_attrs:
setattr(self, attr_name, meta_attrs.pop(attr_name))
self.original_attrs[attr_name] = getattr(self, attr_name)
elif hasattr(self.meta, attr_name):
setattr(self, attr_name, getattr(self.meta, attr_name))
self.original_attrs[attr_name] = getattr(self, attr_name)
self.unique_together = normalize_together(self.unique_together)
self.index_together = normalize_together(self.index_together)
if self.index_together:
warnings.warn(
f"'index_together' is deprecated. Use 'Meta.indexes' in "
f"{self.label!r} instead.",
RemovedInDjango51Warning,
)
# App label/class name interpolation for names of constraints and
# indexes.
if not getattr(cls._meta, "abstract", False):
for attr_name in {"constraints", "indexes"}:
objs = getattr(self, attr_name, [])
setattr(self, attr_name, self._format_names_with_class(cls, objs))
# verbose_name_plural is a special case because it uses a 's'
# by default.
if self.verbose_name_plural is None:
self.verbose_name_plural = format_lazy("{}s", self.verbose_name)
# order_with_respect_and ordering are mutually exclusive.
self._ordering_clash = bool(self.ordering and self.order_with_respect_to)
# Any leftover attributes must be invalid.
if meta_attrs != {}:
raise TypeError(
"'class Meta' got invalid attribute(s): %s" % ",".join(meta_attrs)
)
else:
self.verbose_name_plural = format_lazy("{}s", self.verbose_name)
del self.meta
# If the db_table wasn't provided, use the app_label + model_name.
if not self.db_table:
self.db_table = "%s_%s" % (self.app_label, self.model_name)
self.db_table = truncate_name(
self.db_table, connection.ops.max_name_length()
)
def _format_names_with_class(self, cls, objs):
"""App label/class name interpolation for object names."""
new_objs = []
for obj in objs:
obj = obj.clone()
obj.name = obj.name % {
"app_label": cls._meta.app_label.lower(),
"class": cls.__name__.lower(),
}
new_objs.append(obj)
return new_objs
def _get_default_pk_class(self):
pk_class_path = getattr(
self.app_config,
"default_auto_field",
settings.DEFAULT_AUTO_FIELD,
)
if self.app_config and self.app_config._is_default_auto_field_overridden:
app_config_class = type(self.app_config)
source = (
f"{app_config_class.__module__}."
f"{app_config_class.__qualname__}.default_auto_field"
)
else:
source = "DEFAULT_AUTO_FIELD"
if not pk_class_path:
raise ImproperlyConfigured(f"{source} must not be empty.")
try:
pk_class = import_string(pk_class_path)
except ImportError as e:
msg = (
f"{source} refers to the module '{pk_class_path}' that could "
f"not be imported."
)
raise ImproperlyConfigured(msg) from e
if not issubclass(pk_class, AutoField):
raise ValueError(
f"Primary key '{pk_class_path}' referred by {source} must "
f"subclass AutoField."
)
return pk_class
def _prepare(self, model):
if self.order_with_respect_to:
# The app registry will not be ready at this point, so we cannot
# use get_field().
query = self.order_with_respect_to
try:
self.order_with_respect_to = next(
f
for f in self._get_fields(reverse=False)
if f.name == query or f.attname == query
)
except StopIteration:
raise FieldDoesNotExist(
"%s has no field named '%s'" % (self.object_name, query)
)
self.ordering = ("_order",)
if not any(
isinstance(field, OrderWrt) for field in model._meta.local_fields
):
model.add_to_class("_order", OrderWrt())
else:
self.order_with_respect_to = None
if self.pk is None:
if self.parents:
# Promote the first parent link in lieu of adding yet another
# field.
field = next(iter(self.parents.values()))
# Look for a local field with the same name as the
# first parent link. If a local field has already been
# created, use it instead of promoting the parent
already_created = [
fld for fld in self.local_fields if fld.name == field.name
]
if already_created:
field = already_created[0]
field.primary_key = True
self.setup_pk(field)
else:
pk_class = self._get_default_pk_class()
auto = pk_class(verbose_name="ID", primary_key=True, auto_created=True)
model.add_to_class("id", auto)
def add_manager(self, manager):
self.local_managers.append(manager)
self._expire_cache()
def add_field(self, field, private=False):
# Insert the given field in the order in which it was created, using
# the "creation_counter" attribute of the field.
# Move many-to-many related fields from self.fields into
# self.many_to_many.
if private:
self.private_fields.append(field)
elif field.is_relation and field.many_to_many:
bisect.insort(self.local_many_to_many, field)
else:
bisect.insort(self.local_fields, field)
self.setup_pk(field)
# If the field being added is a relation to another known field,
# expire the cache on this field and the forward cache on the field
# being referenced, because there will be new relationships in the
# cache. Otherwise, expire the cache of references *to* this field.
# The mechanism for getting at the related model is slightly odd -
# ideally, we'd just ask for field.related_model. However, related_model
# is a cached property, and all the models haven't been loaded yet, so
# we need to make sure we don't cache a string reference.
if (
field.is_relation
and hasattr(field.remote_field, "model")
and field.remote_field.model
):
try:
field.remote_field.model._meta._expire_cache(forward=False)
except AttributeError:
pass
self._expire_cache()
else:
self._expire_cache(reverse=False)
def setup_pk(self, field):
if not self.pk and field.primary_key:
self.pk = field
field.serialize = False
def setup_proxy(self, target):
"""
Do the internal setup so that the current model is a proxy for
"target".
"""
self.pk = target._meta.pk
self.proxy_for_model = target
self.db_table = target._meta.db_table
def __repr__(self):
return "<Options for %s>" % self.object_name
def __str__(self):
return self.label_lower
def can_migrate(self, connection):
"""
Return True if the model can/should be migrated on the `connection`.
`connection` can be either a real connection or a connection alias.
"""
if self.proxy or self.swapped or not self.managed:
return False
if isinstance(connection, str):
connection = connections[connection]
if self.required_db_vendor:
return self.required_db_vendor == connection.vendor
if self.required_db_features:
return all(
getattr(connection.features, feat, False)
for feat in self.required_db_features
)
return True
@property
def verbose_name_raw(self):
"""Return the untranslated verbose name."""
with override(None):
return str(self.verbose_name)
@property
def swapped(self):
"""
Has this model been swapped out for another? If so, return the model
name of the replacement; otherwise, return None.
For historical reasons, model name lookups using get_model() are
case insensitive, so we make sure we are case insensitive here.
"""
if self.swappable:
swapped_for = getattr(settings, self.swappable, None)
if swapped_for:
try:
swapped_label, swapped_object = swapped_for.split(".")
except ValueError:
# setting not in the format app_label.model_name
# raising ImproperlyConfigured here causes problems with
# test cleanup code - instead it is raised in get_user_model
# or as part of validation.
return swapped_for
if (
"%s.%s" % (swapped_label, swapped_object.lower())
!= self.label_lower
):
return swapped_for
return None
@cached_property
def managers(self):
managers = []
seen_managers = set()
bases = (b for b in self.model.mro() if hasattr(b, "_meta"))
for depth, base in enumerate(bases):
for manager in base._meta.local_managers:
if manager.name in seen_managers:
continue
manager = copy.copy(manager)
manager.model = self.model
seen_managers.add(manager.name)
managers.append((depth, manager.creation_counter, manager))
return make_immutable_fields_list(
"managers",
(m[2] for m in sorted(managers)),
)
@cached_property
def managers_map(self):
return {manager.name: manager for manager in self.managers}
@cached_property
def base_manager(self):
base_manager_name = self.base_manager_name
if not base_manager_name:
# Get the first parent's base_manager_name if there's one.
for parent in self.model.mro()[1:]:
if hasattr(parent, "_meta"):
if parent._base_manager.name != "_base_manager":
base_manager_name = parent._base_manager.name
break
if base_manager_name:
try:
return self.managers_map[base_manager_name]
except KeyError:
raise ValueError(
"%s has no manager named %r"
% (
self.object_name,
base_manager_name,
)
)
manager = Manager()
manager.name = "_base_manager"
manager.model = self.model
manager.auto_created = True
return manager
@cached_property
def default_manager(self):
default_manager_name = self.default_manager_name
if not default_manager_name and not self.local_managers:
# Get the first parent's default_manager_name if there's one.
for parent in self.model.mro()[1:]:
if hasattr(parent, "_meta"):
default_manager_name = parent._meta.default_manager_name
break
if default_manager_name:
try:
return self.managers_map[default_manager_name]
except KeyError:
raise ValueError(
"%s has no manager named %r"
% (
self.object_name,
default_manager_name,
)
)
if self.managers:
return self.managers[0]
@cached_property
def fields(self):
"""
Return a list of all forward fields on the model and its parents,
excluding ManyToManyFields.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
# For legacy reasons, the fields property should only contain forward
# fields that are not private or with a m2m cardinality. Therefore we
# pass these three filters as filters to the generator.
# The third lambda is a longwinded way of checking f.related_model - we don't
# use that property directly because related_model is a cached property,
# and all the models may not have been loaded yet; we don't want to cache
# the string reference to the related_model.
def is_not_an_m2m_field(f):
return not (f.is_relation and f.many_to_many)
def is_not_a_generic_relation(f):
return not (f.is_relation and f.one_to_many)
def is_not_a_generic_foreign_key(f):
return not (
f.is_relation
and f.many_to_one
and not (hasattr(f.remote_field, "model") and f.remote_field.model)
)
return make_immutable_fields_list(
"fields",
(
f
for f in self._get_fields(reverse=False)
if is_not_an_m2m_field(f)
and is_not_a_generic_relation(f)
and is_not_a_generic_foreign_key(f)
),
)
@cached_property
def concrete_fields(self):
"""
Return a list of all concrete fields on the model and its parents.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
return make_immutable_fields_list(
"concrete_fields", (f for f in self.fields if f.concrete)
)
@cached_property
def local_concrete_fields(self):
"""
Return a list of all concrete fields on the model.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
return make_immutable_fields_list(
"local_concrete_fields", (f for f in self.local_fields if f.concrete)
)
@cached_property
def many_to_many(self):
"""
Return a list of all many to many fields on the model and its parents.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this list.
"""
return make_immutable_fields_list(
"many_to_many",
(
f
for f in self._get_fields(reverse=False)
if f.is_relation and f.many_to_many
),
)
@cached_property
def related_objects(self):
"""
Return all related objects pointing to the current model. The related
objects can come from a one-to-one, one-to-many, or many-to-many field
relation type.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
all_related_fields = self._get_fields(
forward=False, reverse=True, include_hidden=True
)
return make_immutable_fields_list(
"related_objects",
(
obj
for obj in all_related_fields
if not obj.hidden or obj.field.many_to_many
),
)
@cached_property
def _forward_fields_map(self):
res = {}
fields = self._get_fields(reverse=False)
for field in fields:
res[field.name] = field
# Due to the way Django's internals work, get_field() should also
# be able to fetch a field by attname. In the case of a concrete
# field with relation, includes the *_id name too
try:
res[field.attname] = field
except AttributeError:
pass
return res
@cached_property
def fields_map(self):
res = {}
fields = self._get_fields(forward=False, include_hidden=True)
for field in fields:
res[field.name] = field
# Due to the way Django's internals work, get_field() should also
# be able to fetch a field by attname. In the case of a concrete
# field with relation, includes the *_id name too
try:
res[field.attname] = field
except AttributeError:
pass
return res
def get_field(self, field_name):
"""
Return a field instance given the name of a forward or reverse field.
"""
try:
# In order to avoid premature loading of the relation tree
# (expensive) we prefer checking if the field is a forward field.
return self._forward_fields_map[field_name]
except KeyError:
# If the app registry is not ready, reverse fields are
# unavailable, therefore we throw a FieldDoesNotExist exception.
if not self.apps.models_ready:
raise FieldDoesNotExist(
"%s has no field named '%s'. The app cache isn't ready yet, "
"so if this is an auto-created related field, it won't "
"be available yet." % (self.object_name, field_name)
)
try:
# Retrieve field instance by name from cached or just-computed
# field map.
return self.fields_map[field_name]
except KeyError:
raise FieldDoesNotExist(
"%s has no field named '%s'" % (self.object_name, field_name)
)
def get_base_chain(self, model):
"""
Return a list of parent classes leading to `model` (ordered from
closest to most distant ancestor). This has to handle the case where
`model` is a grandparent or even more distant relation.
"""
if not self.parents:
return []
if model in self.parents:
return [model]
for parent in self.parents:
res = parent._meta.get_base_chain(model)
if res:
res.insert(0, parent)
return res
return []
def get_parent_list(self):
"""
Return all the ancestors of this model as a list ordered by MRO.
Useful for determining if something is an ancestor, regardless of lineage.
"""
result = OrderedSet(self.parents)
for parent in self.parents:
for ancestor in parent._meta.get_parent_list():
result.add(ancestor)
return list(result)
def get_ancestor_link(self, ancestor):
"""
Return the field on the current model which points to the given
"ancestor". This is possible an indirect link (a pointer to a parent
model, which points, eventually, to the ancestor). Used when
constructing table joins for model inheritance.
Return None if the model isn't an ancestor of this one.
"""
if ancestor in self.parents:
return self.parents[ancestor]
for parent in self.parents:
# Tries to get a link field from the immediate parent
parent_link = parent._meta.get_ancestor_link(ancestor)
if parent_link:
# In case of a proxied model, the first link
# of the chain to the ancestor is that parent
# links
return self.parents[parent] or parent_link
def get_path_to_parent(self, parent):
"""
Return a list of PathInfos containing the path from the current
model to the parent model, or an empty list if parent is not a
parent of the current model.
"""
if self.model is parent:
return []
# Skip the chain of proxy to the concrete proxied model.
proxied_model = self.concrete_model
path = []
opts = self
for int_model in self.get_base_chain(parent):
if int_model is proxied_model:
opts = int_model._meta
else:
final_field = opts.parents[int_model]
targets = (final_field.remote_field.get_related_field(),)
opts = int_model._meta
path.append(
PathInfo(
from_opts=final_field.model._meta,
to_opts=opts,
target_fields=targets,
join_field=final_field,
m2m=False,
direct=True,
filtered_relation=None,
)
)
return path
def get_path_from_parent(self, parent):
"""
Return a list of PathInfos containing the path from the parent
model to the current model, or an empty list if parent is not a
parent of the current model.
"""
if self.model is parent:
return []
model = self.concrete_model
# Get a reversed base chain including both the current and parent
# models.
chain = model._meta.get_base_chain(parent)
chain.reverse()
chain.append(model)
# Construct a list of the PathInfos between models in chain.
path = []
for i, ancestor in enumerate(chain[:-1]):
child = chain[i + 1]
link = child._meta.get_ancestor_link(ancestor)
path.extend(link.reverse_path_infos)
return path
def _populate_directed_relation_graph(self):
"""
This method is used by each model to find its reverse objects. As this
method is very expensive and is accessed frequently (it looks up every
field in a model, in every app), it is computed on first access and then
is set as a property on every model.
"""
related_objects_graph = defaultdict(list)
all_models = self.apps.get_models(include_auto_created=True)
for model in all_models:
opts = model._meta
# Abstract model's fields are copied to child models, hence we will
# see the fields from the child models.
if opts.abstract:
continue
fields_with_relations = (
f
for f in opts._get_fields(reverse=False, include_parents=False)
if f.is_relation and f.related_model is not None
)
for f in fields_with_relations:
if not isinstance(f.remote_field.model, str):
remote_label = f.remote_field.model._meta.concrete_model._meta.label
related_objects_graph[remote_label].append(f)
for model in all_models:
# Set the relation_tree using the internal __dict__. In this way
# we avoid calling the cached property. In attribute lookup,
# __dict__ takes precedence over a data descriptor (such as
# @cached_property). This means that the _meta._relation_tree is
# only called if related_objects is not in __dict__.
related_objects = related_objects_graph[
model._meta.concrete_model._meta.label
]
model._meta.__dict__["_relation_tree"] = related_objects
# It seems it is possible that self is not in all_models, so guard
# against that with default for get().
return self.__dict__.get("_relation_tree", EMPTY_RELATION_TREE)
@cached_property
def _relation_tree(self):
return self._populate_directed_relation_graph()
def _expire_cache(self, forward=True, reverse=True):
# This method is usually called by apps.cache_clear(), when the
# registry is finalized, or when a new field is added.
if forward:
for cache_key in self.FORWARD_PROPERTIES:
if cache_key in self.__dict__:
delattr(self, cache_key)
if reverse and not self.abstract:
for cache_key in self.REVERSE_PROPERTIES:
if cache_key in self.__dict__:
delattr(self, cache_key)
self._get_fields_cache = {}
def get_fields(self, include_parents=True, include_hidden=False):
"""
Return a list of fields associated to the model. By default, include
forward and reverse fields, fields derived from inheritance, but not
hidden fields. The returned fields can be changed using the parameters:
- include_parents: include fields derived from inheritance
- include_hidden: include fields that have a related_name that
starts with a "+"
"""
if include_parents is False:
include_parents = PROXY_PARENTS
return self._get_fields(
include_parents=include_parents, include_hidden=include_hidden
)
def _get_fields(
self,
forward=True,
reverse=True,
include_parents=True,
include_hidden=False,
seen_models=None,
):
"""
Internal helper function to return fields of the model.
* If forward=True, then fields defined on this model are returned.
* If reverse=True, then relations pointing to this model are returned.
* If include_hidden=True, then fields with is_hidden=True are returned.
* The include_parents argument toggles if fields from parent models
should be included. It has three values: True, False, and
PROXY_PARENTS. When set to PROXY_PARENTS, the call will return all
fields defined for the current model or any of its parents in the
parent chain to the model's concrete model.
"""
if include_parents not in (True, False, PROXY_PARENTS):
raise TypeError(
"Invalid argument for include_parents: %s" % (include_parents,)
)
# This helper function is used to allow recursion in ``get_fields()``
# implementation and to provide a fast way for Django's internals to
# access specific subsets of fields.
# We must keep track of which models we have already seen. Otherwise we
# could include the same field multiple times from different models.
topmost_call = seen_models is None
if topmost_call:
seen_models = set()
seen_models.add(self.model)
# Creates a cache key composed of all arguments
cache_key = (forward, reverse, include_parents, include_hidden, topmost_call)
try:
# In order to avoid list manipulation. Always return a shallow copy
# of the results.
return self._get_fields_cache[cache_key]
except KeyError:
pass
fields = []
# Recursively call _get_fields() on each parent, with the same
# options provided in this call.
if include_parents is not False:
for parent in self.parents:
# In diamond inheritance it is possible that we see the same
# model from two different routes. In that case, avoid adding
# fields from the same parent again.
if parent in seen_models:
continue
if (
parent._meta.concrete_model != self.concrete_model
and include_parents == PROXY_PARENTS
):
continue
for obj in parent._meta._get_fields(
forward=forward,
reverse=reverse,
include_parents=include_parents,
include_hidden=include_hidden,
seen_models=seen_models,
):
if (
not getattr(obj, "parent_link", False)
or obj.model == self.concrete_model
):
fields.append(obj)
if reverse and not self.proxy:
# Tree is computed once and cached until the app cache is expired.
# It is composed of a list of fields pointing to the current model
# from other models.
all_fields = self._relation_tree
for field in all_fields:
# If hidden fields should be included or the relation is not
# intentionally hidden, add to the fields dict.
if include_hidden or not field.remote_field.hidden:
fields.append(field.remote_field)
if forward:
fields += self.local_fields
fields += self.local_many_to_many
# Private fields are recopied to each child model, and they get a
# different model as field.model in each child. Hence we have to
# add the private fields separately from the topmost call. If we
# did this recursively similar to local_fields, we would get field
# instances with field.model != self.model.
if topmost_call:
fields += self.private_fields
# In order to avoid list manipulation. Always
# return a shallow copy of the results
fields = make_immutable_fields_list("get_fields()", fields)
# Store result into cache for later access
self._get_fields_cache[cache_key] = fields
return fields
@cached_property
def total_unique_constraints(self):
"""
Return a list of total unique constraints. Useful for determining set
of fields guaranteed to be unique for all rows.
"""
return [
constraint
for constraint in self.constraints
if (
isinstance(constraint, UniqueConstraint)
and constraint.condition is None
and not constraint.contains_expressions
)
]
@cached_property
def _property_names(self):
"""Return a set of the names of the properties defined on the model."""
names = []
for name in dir(self.model):
attr = inspect.getattr_static(self.model, name)
if isinstance(attr, property):
names.append(name)
return frozenset(names)
@cached_property
def _non_pk_concrete_field_names(self):
"""
Return a set of the non-pk concrete field names defined on the model.
"""
names = []
for field in self.concrete_fields:
if not field.primary_key:
names.append(field.name)
if field.name != field.attname:
names.append(field.attname)
return frozenset(names)
@cached_property
def db_returning_fields(self):
"""
Private API intended only to be used by Django itself.
Fields to be returned after a database insert.
"""
return [
field
for field in self._get_fields(
forward=True, reverse=False, include_parents=PROXY_PARENTS
)
if getattr(field, "db_returning", False)
]
|
castiel248/Convert
|
Lib/site-packages/django/db/models/options.py
|
Python
|
mit
| 38,977 |
"""
The main QuerySet implementation. This provides the public API for the ORM.
"""
import copy
import operator
import warnings
from itertools import chain, islice
from asgiref.sync import sync_to_async
import django
from django.conf import settings
from django.core import exceptions
from django.db import (
DJANGO_VERSION_PICKLE_KEY,
IntegrityError,
NotSupportedError,
connections,
router,
transaction,
)
from django.db.models import AutoField, DateField, DateTimeField, Field, sql
from django.db.models.constants import LOOKUP_SEP, OnConflict
from django.db.models.deletion import Collector
from django.db.models.expressions import Case, F, Value, When
from django.db.models.functions import Cast, Trunc
from django.db.models.query_utils import FilteredRelation, Q
from django.db.models.sql.constants import CURSOR, GET_ITERATOR_CHUNK_SIZE
from django.db.models.utils import (
AltersData,
create_namedtuple_class,
resolve_callables,
)
from django.utils import timezone
from django.utils.deprecation import RemovedInDjango50Warning
from django.utils.functional import cached_property, partition
# The maximum number of results to fetch in a get() query.
MAX_GET_RESULTS = 21
# The maximum number of items to display in a QuerySet.__repr__
REPR_OUTPUT_SIZE = 20
class BaseIterable:
def __init__(
self, queryset, chunked_fetch=False, chunk_size=GET_ITERATOR_CHUNK_SIZE
):
self.queryset = queryset
self.chunked_fetch = chunked_fetch
self.chunk_size = chunk_size
async def _async_generator(self):
# Generators don't actually start running until the first time you call
# next() on them, so make the generator object in the async thread and
# then repeatedly dispatch to it in a sync thread.
sync_generator = self.__iter__()
def next_slice(gen):
return list(islice(gen, self.chunk_size))
while True:
chunk = await sync_to_async(next_slice)(sync_generator)
for item in chunk:
yield item
if len(chunk) < self.chunk_size:
break
# __aiter__() is a *synchronous* method that has to then return an
# *asynchronous* iterator/generator. Thus, nest an async generator inside
# it.
# This is a generic iterable converter for now, and is going to suffer a
# performance penalty on large sets of items due to the cost of crossing
# over the sync barrier for each chunk. Custom __aiter__() methods should
# be added to each Iterable subclass, but that needs some work in the
# Compiler first.
def __aiter__(self):
return self._async_generator()
class ModelIterable(BaseIterable):
"""Iterable that yields a model instance for each row."""
def __iter__(self):
queryset = self.queryset
db = queryset.db
compiler = queryset.query.get_compiler(using=db)
# Execute the query. This will also fill compiler.select, klass_info,
# and annotations.
results = compiler.execute_sql(
chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size
)
select, klass_info, annotation_col_map = (
compiler.select,
compiler.klass_info,
compiler.annotation_col_map,
)
model_cls = klass_info["model"]
select_fields = klass_info["select_fields"]
model_fields_start, model_fields_end = select_fields[0], select_fields[-1] + 1
init_list = [
f[0].target.attname for f in select[model_fields_start:model_fields_end]
]
related_populators = get_related_populators(klass_info, select, db)
known_related_objects = [
(
field,
related_objs,
operator.attrgetter(
*[
field.attname
if from_field == "self"
else queryset.model._meta.get_field(from_field).attname
for from_field in field.from_fields
]
),
)
for field, related_objs in queryset._known_related_objects.items()
]
for row in compiler.results_iter(results):
obj = model_cls.from_db(
db, init_list, row[model_fields_start:model_fields_end]
)
for rel_populator in related_populators:
rel_populator.populate(row, obj)
if annotation_col_map:
for attr_name, col_pos in annotation_col_map.items():
setattr(obj, attr_name, row[col_pos])
# Add the known related objects to the model.
for field, rel_objs, rel_getter in known_related_objects:
# Avoid overwriting objects loaded by, e.g., select_related().
if field.is_cached(obj):
continue
rel_obj_id = rel_getter(obj)
try:
rel_obj = rel_objs[rel_obj_id]
except KeyError:
pass # May happen in qs1 | qs2 scenarios.
else:
setattr(obj, field.name, rel_obj)
yield obj
class RawModelIterable(BaseIterable):
"""
Iterable that yields a model instance for each row from a raw queryset.
"""
def __iter__(self):
# Cache some things for performance reasons outside the loop.
db = self.queryset.db
query = self.queryset.query
connection = connections[db]
compiler = connection.ops.compiler("SQLCompiler")(query, connection, db)
query_iterator = iter(query)
try:
(
model_init_names,
model_init_pos,
annotation_fields,
) = self.queryset.resolve_model_init_order()
model_cls = self.queryset.model
if model_cls._meta.pk.attname not in model_init_names:
raise exceptions.FieldDoesNotExist(
"Raw query must include the primary key"
)
fields = [self.queryset.model_fields.get(c) for c in self.queryset.columns]
converters = compiler.get_converters(
[f.get_col(f.model._meta.db_table) if f else None for f in fields]
)
if converters:
query_iterator = compiler.apply_converters(query_iterator, converters)
for values in query_iterator:
# Associate fields to values
model_init_values = [values[pos] for pos in model_init_pos]
instance = model_cls.from_db(db, model_init_names, model_init_values)
if annotation_fields:
for column, pos in annotation_fields:
setattr(instance, column, values[pos])
yield instance
finally:
# Done iterating the Query. If it has its own cursor, close it.
if hasattr(query, "cursor") and query.cursor:
query.cursor.close()
class ValuesIterable(BaseIterable):
"""
Iterable returned by QuerySet.values() that yields a dict for each row.
"""
def __iter__(self):
queryset = self.queryset
query = queryset.query
compiler = query.get_compiler(queryset.db)
# extra(select=...) cols are always at the start of the row.
names = [
*query.extra_select,
*query.values_select,
*query.annotation_select,
]
indexes = range(len(names))
for row in compiler.results_iter(
chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size
):
yield {names[i]: row[i] for i in indexes}
class ValuesListIterable(BaseIterable):
"""
Iterable returned by QuerySet.values_list(flat=False) that yields a tuple
for each row.
"""
def __iter__(self):
queryset = self.queryset
query = queryset.query
compiler = query.get_compiler(queryset.db)
if queryset._fields:
# extra(select=...) cols are always at the start of the row.
names = [
*query.extra_select,
*query.values_select,
*query.annotation_select,
]
fields = [
*queryset._fields,
*(f for f in query.annotation_select if f not in queryset._fields),
]
if fields != names:
# Reorder according to fields.
index_map = {name: idx for idx, name in enumerate(names)}
rowfactory = operator.itemgetter(*[index_map[f] for f in fields])
return map(
rowfactory,
compiler.results_iter(
chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size
),
)
return compiler.results_iter(
tuple_expected=True,
chunked_fetch=self.chunked_fetch,
chunk_size=self.chunk_size,
)
class NamedValuesListIterable(ValuesListIterable):
"""
Iterable returned by QuerySet.values_list(named=True) that yields a
namedtuple for each row.
"""
def __iter__(self):
queryset = self.queryset
if queryset._fields:
names = queryset._fields
else:
query = queryset.query
names = [
*query.extra_select,
*query.values_select,
*query.annotation_select,
]
tuple_class = create_namedtuple_class(*names)
new = tuple.__new__
for row in super().__iter__():
yield new(tuple_class, row)
class FlatValuesListIterable(BaseIterable):
"""
Iterable returned by QuerySet.values_list(flat=True) that yields single
values.
"""
def __iter__(self):
queryset = self.queryset
compiler = queryset.query.get_compiler(queryset.db)
for row in compiler.results_iter(
chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size
):
yield row[0]
class QuerySet(AltersData):
"""Represent a lazy database lookup for a set of objects."""
def __init__(self, model=None, query=None, using=None, hints=None):
self.model = model
self._db = using
self._hints = hints or {}
self._query = query or sql.Query(self.model)
self._result_cache = None
self._sticky_filter = False
self._for_write = False
self._prefetch_related_lookups = ()
self._prefetch_done = False
self._known_related_objects = {} # {rel_field: {pk: rel_obj}}
self._iterable_class = ModelIterable
self._fields = None
self._defer_next_filter = False
self._deferred_filter = None
@property
def query(self):
if self._deferred_filter:
negate, args, kwargs = self._deferred_filter
self._filter_or_exclude_inplace(negate, args, kwargs)
self._deferred_filter = None
return self._query
@query.setter
def query(self, value):
if value.values_select:
self._iterable_class = ValuesIterable
self._query = value
def as_manager(cls):
# Address the circular dependency between `Queryset` and `Manager`.
from django.db.models.manager import Manager
manager = Manager.from_queryset(cls)()
manager._built_with_as_manager = True
return manager
as_manager.queryset_only = True
as_manager = classmethod(as_manager)
########################
# PYTHON MAGIC METHODS #
########################
def __deepcopy__(self, memo):
"""Don't populate the QuerySet's cache."""
obj = self.__class__()
for k, v in self.__dict__.items():
if k == "_result_cache":
obj.__dict__[k] = None
else:
obj.__dict__[k] = copy.deepcopy(v, memo)
return obj
def __getstate__(self):
# Force the cache to be fully populated.
self._fetch_all()
return {**self.__dict__, DJANGO_VERSION_PICKLE_KEY: django.__version__}
def __setstate__(self, state):
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
if pickled_version:
if pickled_version != django.__version__:
warnings.warn(
"Pickled queryset instance's Django version %s does not "
"match the current version %s."
% (pickled_version, django.__version__),
RuntimeWarning,
stacklevel=2,
)
else:
warnings.warn(
"Pickled queryset instance's Django version is not specified.",
RuntimeWarning,
stacklevel=2,
)
self.__dict__.update(state)
def __repr__(self):
data = list(self[: REPR_OUTPUT_SIZE + 1])
if len(data) > REPR_OUTPUT_SIZE:
data[-1] = "...(remaining elements truncated)..."
return "<%s %r>" % (self.__class__.__name__, data)
def __len__(self):
self._fetch_all()
return len(self._result_cache)
def __iter__(self):
"""
The queryset iterator protocol uses three nested iterators in the
default case:
1. sql.compiler.execute_sql()
- Returns 100 rows at time (constants.GET_ITERATOR_CHUNK_SIZE)
using cursor.fetchmany(). This part is responsible for
doing some column masking, and returning the rows in chunks.
2. sql.compiler.results_iter()
- Returns one row at time. At this point the rows are still just
tuples. In some cases the return values are converted to
Python values at this location.
3. self.iterator()
- Responsible for turning the rows into model objects.
"""
self._fetch_all()
return iter(self._result_cache)
def __aiter__(self):
# Remember, __aiter__ itself is synchronous, it's the thing it returns
# that is async!
async def generator():
await sync_to_async(self._fetch_all)()
for item in self._result_cache:
yield item
return generator()
def __bool__(self):
self._fetch_all()
return bool(self._result_cache)
def __getitem__(self, k):
"""Retrieve an item or slice from the set of results."""
if not isinstance(k, (int, slice)):
raise TypeError(
"QuerySet indices must be integers or slices, not %s."
% type(k).__name__
)
if (isinstance(k, int) and k < 0) or (
isinstance(k, slice)
and (
(k.start is not None and k.start < 0)
or (k.stop is not None and k.stop < 0)
)
):
raise ValueError("Negative indexing is not supported.")
if self._result_cache is not None:
return self._result_cache[k]
if isinstance(k, slice):
qs = self._chain()
if k.start is not None:
start = int(k.start)
else:
start = None
if k.stop is not None:
stop = int(k.stop)
else:
stop = None
qs.query.set_limits(start, stop)
return list(qs)[:: k.step] if k.step else qs
qs = self._chain()
qs.query.set_limits(k, k + 1)
qs._fetch_all()
return qs._result_cache[0]
def __class_getitem__(cls, *args, **kwargs):
return cls
def __and__(self, other):
self._check_operator_queryset(other, "&")
self._merge_sanity_check(other)
if isinstance(other, EmptyQuerySet):
return other
if isinstance(self, EmptyQuerySet):
return self
combined = self._chain()
combined._merge_known_related_objects(other)
combined.query.combine(other.query, sql.AND)
return combined
def __or__(self, other):
self._check_operator_queryset(other, "|")
self._merge_sanity_check(other)
if isinstance(self, EmptyQuerySet):
return other
if isinstance(other, EmptyQuerySet):
return self
query = (
self
if self.query.can_filter()
else self.model._base_manager.filter(pk__in=self.values("pk"))
)
combined = query._chain()
combined._merge_known_related_objects(other)
if not other.query.can_filter():
other = other.model._base_manager.filter(pk__in=other.values("pk"))
combined.query.combine(other.query, sql.OR)
return combined
def __xor__(self, other):
self._check_operator_queryset(other, "^")
self._merge_sanity_check(other)
if isinstance(self, EmptyQuerySet):
return other
if isinstance(other, EmptyQuerySet):
return self
query = (
self
if self.query.can_filter()
else self.model._base_manager.filter(pk__in=self.values("pk"))
)
combined = query._chain()
combined._merge_known_related_objects(other)
if not other.query.can_filter():
other = other.model._base_manager.filter(pk__in=other.values("pk"))
combined.query.combine(other.query, sql.XOR)
return combined
####################################
# METHODS THAT DO DATABASE QUERIES #
####################################
def _iterator(self, use_chunked_fetch, chunk_size):
iterable = self._iterable_class(
self,
chunked_fetch=use_chunked_fetch,
chunk_size=chunk_size or 2000,
)
if not self._prefetch_related_lookups or chunk_size is None:
yield from iterable
return
iterator = iter(iterable)
while results := list(islice(iterator, chunk_size)):
prefetch_related_objects(results, *self._prefetch_related_lookups)
yield from results
def iterator(self, chunk_size=None):
"""
An iterator over the results from applying this QuerySet to the
database. chunk_size must be provided for QuerySets that prefetch
related objects. Otherwise, a default chunk_size of 2000 is supplied.
"""
if chunk_size is None:
if self._prefetch_related_lookups:
# When the deprecation ends, replace with:
# raise ValueError(
# 'chunk_size must be provided when using '
# 'QuerySet.iterator() after prefetch_related().'
# )
warnings.warn(
"Using QuerySet.iterator() after prefetch_related() "
"without specifying chunk_size is deprecated.",
category=RemovedInDjango50Warning,
stacklevel=2,
)
elif chunk_size <= 0:
raise ValueError("Chunk size must be strictly positive.")
use_chunked_fetch = not connections[self.db].settings_dict.get(
"DISABLE_SERVER_SIDE_CURSORS"
)
return self._iterator(use_chunked_fetch, chunk_size)
async def aiterator(self, chunk_size=2000):
"""
An asynchronous iterator over the results from applying this QuerySet
to the database.
"""
if self._prefetch_related_lookups:
raise NotSupportedError(
"Using QuerySet.aiterator() after prefetch_related() is not supported."
)
if chunk_size <= 0:
raise ValueError("Chunk size must be strictly positive.")
use_chunked_fetch = not connections[self.db].settings_dict.get(
"DISABLE_SERVER_SIDE_CURSORS"
)
async for item in self._iterable_class(
self, chunked_fetch=use_chunked_fetch, chunk_size=chunk_size
):
yield item
def aggregate(self, *args, **kwargs):
"""
Return a dictionary containing the calculations (aggregation)
over the current queryset.
If args is present the expression is passed as a kwarg using
the Aggregate object's default alias.
"""
if self.query.distinct_fields:
raise NotImplementedError("aggregate() + distinct(fields) not implemented.")
self._validate_values_are_expressions(
(*args, *kwargs.values()), method_name="aggregate"
)
for arg in args:
# The default_alias property raises TypeError if default_alias
# can't be set automatically or AttributeError if it isn't an
# attribute.
try:
arg.default_alias
except (AttributeError, TypeError):
raise TypeError("Complex aggregates require an alias")
kwargs[arg.default_alias] = arg
return self.query.chain().get_aggregation(self.db, kwargs)
async def aaggregate(self, *args, **kwargs):
return await sync_to_async(self.aggregate)(*args, **kwargs)
def count(self):
"""
Perform a SELECT COUNT() and return the number of records as an
integer.
If the QuerySet is already fully cached, return the length of the
cached results set to avoid multiple SELECT COUNT(*) calls.
"""
if self._result_cache is not None:
return len(self._result_cache)
return self.query.get_count(using=self.db)
async def acount(self):
return await sync_to_async(self.count)()
def get(self, *args, **kwargs):
"""
Perform the query and return a single object matching the given
keyword arguments.
"""
if self.query.combinator and (args or kwargs):
raise NotSupportedError(
"Calling QuerySet.get(...) with filters after %s() is not "
"supported." % self.query.combinator
)
clone = self._chain() if self.query.combinator else self.filter(*args, **kwargs)
if self.query.can_filter() and not self.query.distinct_fields:
clone = clone.order_by()
limit = None
if (
not clone.query.select_for_update
or connections[clone.db].features.supports_select_for_update_with_limit
):
limit = MAX_GET_RESULTS
clone.query.set_limits(high=limit)
num = len(clone)
if num == 1:
return clone._result_cache[0]
if not num:
raise self.model.DoesNotExist(
"%s matching query does not exist." % self.model._meta.object_name
)
raise self.model.MultipleObjectsReturned(
"get() returned more than one %s -- it returned %s!"
% (
self.model._meta.object_name,
num if not limit or num < limit else "more than %s" % (limit - 1),
)
)
async def aget(self, *args, **kwargs):
return await sync_to_async(self.get)(*args, **kwargs)
def create(self, **kwargs):
"""
Create a new object with the given kwargs, saving it to the database
and returning the created object.
"""
obj = self.model(**kwargs)
self._for_write = True
obj.save(force_insert=True, using=self.db)
return obj
async def acreate(self, **kwargs):
return await sync_to_async(self.create)(**kwargs)
def _prepare_for_bulk_create(self, objs):
for obj in objs:
if obj.pk is None:
# Populate new PK values.
obj.pk = obj._meta.pk.get_pk_value_on_save(obj)
obj._prepare_related_fields_for_save(operation_name="bulk_create")
def _check_bulk_create_options(
self, ignore_conflicts, update_conflicts, update_fields, unique_fields
):
if ignore_conflicts and update_conflicts:
raise ValueError(
"ignore_conflicts and update_conflicts are mutually exclusive."
)
db_features = connections[self.db].features
if ignore_conflicts:
if not db_features.supports_ignore_conflicts:
raise NotSupportedError(
"This database backend does not support ignoring conflicts."
)
return OnConflict.IGNORE
elif update_conflicts:
if not db_features.supports_update_conflicts:
raise NotSupportedError(
"This database backend does not support updating conflicts."
)
if not update_fields:
raise ValueError(
"Fields that will be updated when a row insertion fails "
"on conflicts must be provided."
)
if unique_fields and not db_features.supports_update_conflicts_with_target:
raise NotSupportedError(
"This database backend does not support updating "
"conflicts with specifying unique fields that can trigger "
"the upsert."
)
if not unique_fields and db_features.supports_update_conflicts_with_target:
raise ValueError(
"Unique fields that can trigger the upsert must be provided."
)
# Updating primary keys and non-concrete fields is forbidden.
if any(not f.concrete or f.many_to_many for f in update_fields):
raise ValueError(
"bulk_create() can only be used with concrete fields in "
"update_fields."
)
if any(f.primary_key for f in update_fields):
raise ValueError(
"bulk_create() cannot be used with primary keys in "
"update_fields."
)
if unique_fields:
if any(not f.concrete or f.many_to_many for f in unique_fields):
raise ValueError(
"bulk_create() can only be used with concrete fields "
"in unique_fields."
)
return OnConflict.UPDATE
return None
def bulk_create(
self,
objs,
batch_size=None,
ignore_conflicts=False,
update_conflicts=False,
update_fields=None,
unique_fields=None,
):
"""
Insert each of the instances into the database. Do *not* call
save() on each of the instances, do not send any pre/post_save
signals, and do not set the primary key attribute if it is an
autoincrement field (except if features.can_return_rows_from_bulk_insert=True).
Multi-table models are not supported.
"""
# When you bulk insert you don't get the primary keys back (if it's an
# autoincrement, except if can_return_rows_from_bulk_insert=True), so
# you can't insert into the child tables which references this. There
# are two workarounds:
# 1) This could be implemented if you didn't have an autoincrement pk
# 2) You could do it by doing O(n) normal inserts into the parent
# tables to get the primary keys back and then doing a single bulk
# insert into the childmost table.
# We currently set the primary keys on the objects when using
# PostgreSQL via the RETURNING ID clause. It should be possible for
# Oracle as well, but the semantics for extracting the primary keys is
# trickier so it's not done yet.
if batch_size is not None and batch_size <= 0:
raise ValueError("Batch size must be a positive integer.")
# Check that the parents share the same concrete model with the our
# model to detect the inheritance pattern ConcreteGrandParent ->
# MultiTableParent -> ProxyChild. Simply checking self.model._meta.proxy
# would not identify that case as involving multiple tables.
for parent in self.model._meta.get_parent_list():
if parent._meta.concrete_model is not self.model._meta.concrete_model:
raise ValueError("Can't bulk create a multi-table inherited model")
if not objs:
return objs
opts = self.model._meta
if unique_fields:
# Primary key is allowed in unique_fields.
unique_fields = [
self.model._meta.get_field(opts.pk.name if name == "pk" else name)
for name in unique_fields
]
if update_fields:
update_fields = [self.model._meta.get_field(name) for name in update_fields]
on_conflict = self._check_bulk_create_options(
ignore_conflicts,
update_conflicts,
update_fields,
unique_fields,
)
self._for_write = True
fields = opts.concrete_fields
objs = list(objs)
self._prepare_for_bulk_create(objs)
with transaction.atomic(using=self.db, savepoint=False):
objs_with_pk, objs_without_pk = partition(lambda o: o.pk is None, objs)
if objs_with_pk:
returned_columns = self._batched_insert(
objs_with_pk,
fields,
batch_size,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
)
for obj_with_pk, results in zip(objs_with_pk, returned_columns):
for result, field in zip(results, opts.db_returning_fields):
if field != opts.pk:
setattr(obj_with_pk, field.attname, result)
for obj_with_pk in objs_with_pk:
obj_with_pk._state.adding = False
obj_with_pk._state.db = self.db
if objs_without_pk:
fields = [f for f in fields if not isinstance(f, AutoField)]
returned_columns = self._batched_insert(
objs_without_pk,
fields,
batch_size,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
)
connection = connections[self.db]
if (
connection.features.can_return_rows_from_bulk_insert
and on_conflict is None
):
assert len(returned_columns) == len(objs_without_pk)
for obj_without_pk, results in zip(objs_without_pk, returned_columns):
for result, field in zip(results, opts.db_returning_fields):
setattr(obj_without_pk, field.attname, result)
obj_without_pk._state.adding = False
obj_without_pk._state.db = self.db
return objs
async def abulk_create(
self,
objs,
batch_size=None,
ignore_conflicts=False,
update_conflicts=False,
update_fields=None,
unique_fields=None,
):
return await sync_to_async(self.bulk_create)(
objs=objs,
batch_size=batch_size,
ignore_conflicts=ignore_conflicts,
update_conflicts=update_conflicts,
update_fields=update_fields,
unique_fields=unique_fields,
)
def bulk_update(self, objs, fields, batch_size=None):
"""
Update the given fields in each of the given objects in the database.
"""
if batch_size is not None and batch_size <= 0:
raise ValueError("Batch size must be a positive integer.")
if not fields:
raise ValueError("Field names must be given to bulk_update().")
objs = tuple(objs)
if any(obj.pk is None for obj in objs):
raise ValueError("All bulk_update() objects must have a primary key set.")
fields = [self.model._meta.get_field(name) for name in fields]
if any(not f.concrete or f.many_to_many for f in fields):
raise ValueError("bulk_update() can only be used with concrete fields.")
if any(f.primary_key for f in fields):
raise ValueError("bulk_update() cannot be used with primary key fields.")
if not objs:
return 0
for obj in objs:
obj._prepare_related_fields_for_save(
operation_name="bulk_update", fields=fields
)
# PK is used twice in the resulting update query, once in the filter
# and once in the WHEN. Each field will also have one CAST.
self._for_write = True
connection = connections[self.db]
max_batch_size = connection.ops.bulk_batch_size(["pk", "pk"] + fields, objs)
batch_size = min(batch_size, max_batch_size) if batch_size else max_batch_size
requires_casting = connection.features.requires_casted_case_in_updates
batches = (objs[i : i + batch_size] for i in range(0, len(objs), batch_size))
updates = []
for batch_objs in batches:
update_kwargs = {}
for field in fields:
when_statements = []
for obj in batch_objs:
attr = getattr(obj, field.attname)
if not hasattr(attr, "resolve_expression"):
attr = Value(attr, output_field=field)
when_statements.append(When(pk=obj.pk, then=attr))
case_statement = Case(*when_statements, output_field=field)
if requires_casting:
case_statement = Cast(case_statement, output_field=field)
update_kwargs[field.attname] = case_statement
updates.append(([obj.pk for obj in batch_objs], update_kwargs))
rows_updated = 0
queryset = self.using(self.db)
with transaction.atomic(using=self.db, savepoint=False):
for pks, update_kwargs in updates:
rows_updated += queryset.filter(pk__in=pks).update(**update_kwargs)
return rows_updated
bulk_update.alters_data = True
async def abulk_update(self, objs, fields, batch_size=None):
return await sync_to_async(self.bulk_update)(
objs=objs,
fields=fields,
batch_size=batch_size,
)
abulk_update.alters_data = True
def get_or_create(self, defaults=None, **kwargs):
"""
Look up an object with the given kwargs, creating one if necessary.
Return a tuple of (object, created), where created is a boolean
specifying whether an object was created.
"""
# The get() needs to be targeted at the write database in order
# to avoid potential transaction consistency problems.
self._for_write = True
try:
return self.get(**kwargs), False
except self.model.DoesNotExist:
params = self._extract_model_params(defaults, **kwargs)
# Try to create an object using passed params.
try:
with transaction.atomic(using=self.db):
params = dict(resolve_callables(params))
return self.create(**params), True
except IntegrityError:
try:
return self.get(**kwargs), False
except self.model.DoesNotExist:
pass
raise
async def aget_or_create(self, defaults=None, **kwargs):
return await sync_to_async(self.get_or_create)(
defaults=defaults,
**kwargs,
)
def update_or_create(self, defaults=None, **kwargs):
"""
Look up an object with the given kwargs, updating one with defaults
if it exists, otherwise create a new one.
Return a tuple (object, created), where created is a boolean
specifying whether an object was created.
"""
defaults = defaults or {}
self._for_write = True
with transaction.atomic(using=self.db):
# Lock the row so that a concurrent update is blocked until
# update_or_create() has performed its save.
obj, created = self.select_for_update().get_or_create(defaults, **kwargs)
if created:
return obj, created
for k, v in resolve_callables(defaults):
setattr(obj, k, v)
update_fields = set(defaults)
concrete_field_names = self.model._meta._non_pk_concrete_field_names
# update_fields does not support non-concrete fields.
if concrete_field_names.issuperset(update_fields):
# Add fields which are set on pre_save(), e.g. auto_now fields.
# This is to maintain backward compatibility as these fields
# are not updated unless explicitly specified in the
# update_fields list.
for field in self.model._meta.local_concrete_fields:
if not (
field.primary_key or field.__class__.pre_save is Field.pre_save
):
update_fields.add(field.name)
if field.name != field.attname:
update_fields.add(field.attname)
obj.save(using=self.db, update_fields=update_fields)
else:
obj.save(using=self.db)
return obj, False
async def aupdate_or_create(self, defaults=None, **kwargs):
return await sync_to_async(self.update_or_create)(
defaults=defaults,
**kwargs,
)
def _extract_model_params(self, defaults, **kwargs):
"""
Prepare `params` for creating a model instance based on the given
kwargs; for use by get_or_create().
"""
defaults = defaults or {}
params = {k: v for k, v in kwargs.items() if LOOKUP_SEP not in k}
params.update(defaults)
property_names = self.model._meta._property_names
invalid_params = []
for param in params:
try:
self.model._meta.get_field(param)
except exceptions.FieldDoesNotExist:
# It's okay to use a model's property if it has a setter.
if not (param in property_names and getattr(self.model, param).fset):
invalid_params.append(param)
if invalid_params:
raise exceptions.FieldError(
"Invalid field name(s) for model %s: '%s'."
% (
self.model._meta.object_name,
"', '".join(sorted(invalid_params)),
)
)
return params
def _earliest(self, *fields):
"""
Return the earliest object according to fields (if given) or by the
model's Meta.get_latest_by.
"""
if fields:
order_by = fields
else:
order_by = getattr(self.model._meta, "get_latest_by")
if order_by and not isinstance(order_by, (tuple, list)):
order_by = (order_by,)
if order_by is None:
raise ValueError(
"earliest() and latest() require either fields as positional "
"arguments or 'get_latest_by' in the model's Meta."
)
obj = self._chain()
obj.query.set_limits(high=1)
obj.query.clear_ordering(force=True)
obj.query.add_ordering(*order_by)
return obj.get()
def earliest(self, *fields):
if self.query.is_sliced:
raise TypeError("Cannot change a query once a slice has been taken.")
return self._earliest(*fields)
async def aearliest(self, *fields):
return await sync_to_async(self.earliest)(*fields)
def latest(self, *fields):
"""
Return the latest object according to fields (if given) or by the
model's Meta.get_latest_by.
"""
if self.query.is_sliced:
raise TypeError("Cannot change a query once a slice has been taken.")
return self.reverse()._earliest(*fields)
async def alatest(self, *fields):
return await sync_to_async(self.latest)(*fields)
def first(self):
"""Return the first object of a query or None if no match is found."""
if self.ordered:
queryset = self
else:
self._check_ordering_first_last_queryset_aggregation(method="first")
queryset = self.order_by("pk")
for obj in queryset[:1]:
return obj
async def afirst(self):
return await sync_to_async(self.first)()
def last(self):
"""Return the last object of a query or None if no match is found."""
if self.ordered:
queryset = self.reverse()
else:
self._check_ordering_first_last_queryset_aggregation(method="last")
queryset = self.order_by("-pk")
for obj in queryset[:1]:
return obj
async def alast(self):
return await sync_to_async(self.last)()
def in_bulk(self, id_list=None, *, field_name="pk"):
"""
Return a dictionary mapping each of the given IDs to the object with
that ID. If `id_list` isn't provided, evaluate the entire QuerySet.
"""
if self.query.is_sliced:
raise TypeError("Cannot use 'limit' or 'offset' with in_bulk().")
opts = self.model._meta
unique_fields = [
constraint.fields[0]
for constraint in opts.total_unique_constraints
if len(constraint.fields) == 1
]
if (
field_name != "pk"
and not opts.get_field(field_name).unique
and field_name not in unique_fields
and self.query.distinct_fields != (field_name,)
):
raise ValueError(
"in_bulk()'s field_name must be a unique field but %r isn't."
% field_name
)
if id_list is not None:
if not id_list:
return {}
filter_key = "{}__in".format(field_name)
batch_size = connections[self.db].features.max_query_params
id_list = tuple(id_list)
# If the database has a limit on the number of query parameters
# (e.g. SQLite), retrieve objects in batches if necessary.
if batch_size and batch_size < len(id_list):
qs = ()
for offset in range(0, len(id_list), batch_size):
batch = id_list[offset : offset + batch_size]
qs += tuple(self.filter(**{filter_key: batch}).order_by())
else:
qs = self.filter(**{filter_key: id_list}).order_by()
else:
qs = self._chain()
return {getattr(obj, field_name): obj for obj in qs}
async def ain_bulk(self, id_list=None, *, field_name="pk"):
return await sync_to_async(self.in_bulk)(
id_list=id_list,
field_name=field_name,
)
def delete(self):
"""Delete the records in the current QuerySet."""
self._not_support_combined_queries("delete")
if self.query.is_sliced:
raise TypeError("Cannot use 'limit' or 'offset' with delete().")
if self.query.distinct or self.query.distinct_fields:
raise TypeError("Cannot call delete() after .distinct().")
if self._fields is not None:
raise TypeError("Cannot call delete() after .values() or .values_list()")
del_query = self._chain()
# The delete is actually 2 queries - one to find related objects,
# and one to delete. Make sure that the discovery of related
# objects is performed on the same database as the deletion.
del_query._for_write = True
# Disable non-supported fields.
del_query.query.select_for_update = False
del_query.query.select_related = False
del_query.query.clear_ordering(force=True)
collector = Collector(using=del_query.db, origin=self)
collector.collect(del_query)
deleted, _rows_count = collector.delete()
# Clear the result cache, in case this QuerySet gets reused.
self._result_cache = None
return deleted, _rows_count
delete.alters_data = True
delete.queryset_only = True
async def adelete(self):
return await sync_to_async(self.delete)()
adelete.alters_data = True
adelete.queryset_only = True
def _raw_delete(self, using):
"""
Delete objects found from the given queryset in single direct SQL
query. No signals are sent and there is no protection for cascades.
"""
query = self.query.clone()
query.__class__ = sql.DeleteQuery
cursor = query.get_compiler(using).execute_sql(CURSOR)
if cursor:
with cursor:
return cursor.rowcount
return 0
_raw_delete.alters_data = True
def update(self, **kwargs):
"""
Update all elements in the current QuerySet, setting all the given
fields to the appropriate values.
"""
self._not_support_combined_queries("update")
if self.query.is_sliced:
raise TypeError("Cannot update a query once a slice has been taken.")
self._for_write = True
query = self.query.chain(sql.UpdateQuery)
query.add_update_values(kwargs)
# Inline annotations in order_by(), if possible.
new_order_by = []
for col in query.order_by:
if annotation := query.annotations.get(col):
if getattr(annotation, "contains_aggregate", False):
raise exceptions.FieldError(
f"Cannot update when ordering by an aggregate: {annotation}"
)
new_order_by.append(annotation)
else:
new_order_by.append(col)
query.order_by = tuple(new_order_by)
# Clear any annotations so that they won't be present in subqueries.
query.annotations = {}
with transaction.mark_for_rollback_on_error(using=self.db):
rows = query.get_compiler(self.db).execute_sql(CURSOR)
self._result_cache = None
return rows
update.alters_data = True
async def aupdate(self, **kwargs):
return await sync_to_async(self.update)(**kwargs)
aupdate.alters_data = True
def _update(self, values):
"""
A version of update() that accepts field objects instead of field names.
Used primarily for model saving and not intended for use by general
code (it requires too much poking around at model internals to be
useful at that level).
"""
if self.query.is_sliced:
raise TypeError("Cannot update a query once a slice has been taken.")
query = self.query.chain(sql.UpdateQuery)
query.add_update_fields(values)
# Clear any annotations so that they won't be present in subqueries.
query.annotations = {}
self._result_cache = None
return query.get_compiler(self.db).execute_sql(CURSOR)
_update.alters_data = True
_update.queryset_only = False
def exists(self):
"""
Return True if the QuerySet would have any results, False otherwise.
"""
if self._result_cache is None:
return self.query.has_results(using=self.db)
return bool(self._result_cache)
async def aexists(self):
return await sync_to_async(self.exists)()
def contains(self, obj):
"""
Return True if the QuerySet contains the provided obj,
False otherwise.
"""
self._not_support_combined_queries("contains")
if self._fields is not None:
raise TypeError(
"Cannot call QuerySet.contains() after .values() or .values_list()."
)
try:
if obj._meta.concrete_model != self.model._meta.concrete_model:
return False
except AttributeError:
raise TypeError("'obj' must be a model instance.")
if obj.pk is None:
raise ValueError("QuerySet.contains() cannot be used on unsaved objects.")
if self._result_cache is not None:
return obj in self._result_cache
return self.filter(pk=obj.pk).exists()
async def acontains(self, obj):
return await sync_to_async(self.contains)(obj=obj)
def _prefetch_related_objects(self):
# This method can only be called once the result cache has been filled.
prefetch_related_objects(self._result_cache, *self._prefetch_related_lookups)
self._prefetch_done = True
def explain(self, *, format=None, **options):
"""
Runs an EXPLAIN on the SQL query this QuerySet would perform, and
returns the results.
"""
return self.query.explain(using=self.db, format=format, **options)
async def aexplain(self, *, format=None, **options):
return await sync_to_async(self.explain)(format=format, **options)
##################################################
# PUBLIC METHODS THAT RETURN A QUERYSET SUBCLASS #
##################################################
def raw(self, raw_query, params=(), translations=None, using=None):
if using is None:
using = self.db
qs = RawQuerySet(
raw_query,
model=self.model,
params=params,
translations=translations,
using=using,
)
qs._prefetch_related_lookups = self._prefetch_related_lookups[:]
return qs
def _values(self, *fields, **expressions):
clone = self._chain()
if expressions:
clone = clone.annotate(**expressions)
clone._fields = fields
clone.query.set_values(fields)
return clone
def values(self, *fields, **expressions):
fields += tuple(expressions)
clone = self._values(*fields, **expressions)
clone._iterable_class = ValuesIterable
return clone
def values_list(self, *fields, flat=False, named=False):
if flat and named:
raise TypeError("'flat' and 'named' can't be used together.")
if flat and len(fields) > 1:
raise TypeError(
"'flat' is not valid when values_list is called with more than one "
"field."
)
field_names = {f for f in fields if not hasattr(f, "resolve_expression")}
_fields = []
expressions = {}
counter = 1
for field in fields:
if hasattr(field, "resolve_expression"):
field_id_prefix = getattr(
field, "default_alias", field.__class__.__name__.lower()
)
while True:
field_id = field_id_prefix + str(counter)
counter += 1
if field_id not in field_names:
break
expressions[field_id] = field
_fields.append(field_id)
else:
_fields.append(field)
clone = self._values(*_fields, **expressions)
clone._iterable_class = (
NamedValuesListIterable
if named
else FlatValuesListIterable
if flat
else ValuesListIterable
)
return clone
def dates(self, field_name, kind, order="ASC"):
"""
Return a list of date objects representing all available dates for
the given field_name, scoped to 'kind'.
"""
if kind not in ("year", "month", "week", "day"):
raise ValueError("'kind' must be one of 'year', 'month', 'week', or 'day'.")
if order not in ("ASC", "DESC"):
raise ValueError("'order' must be either 'ASC' or 'DESC'.")
return (
self.annotate(
datefield=Trunc(field_name, kind, output_field=DateField()),
plain_field=F(field_name),
)
.values_list("datefield", flat=True)
.distinct()
.filter(plain_field__isnull=False)
.order_by(("-" if order == "DESC" else "") + "datefield")
)
# RemovedInDjango50Warning: when the deprecation ends, remove is_dst
# argument.
def datetimes(
self, field_name, kind, order="ASC", tzinfo=None, is_dst=timezone.NOT_PASSED
):
"""
Return a list of datetime objects representing all available
datetimes for the given field_name, scoped to 'kind'.
"""
if kind not in ("year", "month", "week", "day", "hour", "minute", "second"):
raise ValueError(
"'kind' must be one of 'year', 'month', 'week', 'day', "
"'hour', 'minute', or 'second'."
)
if order not in ("ASC", "DESC"):
raise ValueError("'order' must be either 'ASC' or 'DESC'.")
if settings.USE_TZ:
if tzinfo is None:
tzinfo = timezone.get_current_timezone()
else:
tzinfo = None
return (
self.annotate(
datetimefield=Trunc(
field_name,
kind,
output_field=DateTimeField(),
tzinfo=tzinfo,
is_dst=is_dst,
),
plain_field=F(field_name),
)
.values_list("datetimefield", flat=True)
.distinct()
.filter(plain_field__isnull=False)
.order_by(("-" if order == "DESC" else "") + "datetimefield")
)
def none(self):
"""Return an empty QuerySet."""
clone = self._chain()
clone.query.set_empty()
return clone
##################################################################
# PUBLIC METHODS THAT ALTER ATTRIBUTES AND RETURN A NEW QUERYSET #
##################################################################
def all(self):
"""
Return a new QuerySet that is a copy of the current one. This allows a
QuerySet to proxy for a model manager in some cases.
"""
return self._chain()
def filter(self, *args, **kwargs):
"""
Return a new QuerySet instance with the args ANDed to the existing
set.
"""
self._not_support_combined_queries("filter")
return self._filter_or_exclude(False, args, kwargs)
def exclude(self, *args, **kwargs):
"""
Return a new QuerySet instance with NOT (args) ANDed to the existing
set.
"""
self._not_support_combined_queries("exclude")
return self._filter_or_exclude(True, args, kwargs)
def _filter_or_exclude(self, negate, args, kwargs):
if (args or kwargs) and self.query.is_sliced:
raise TypeError("Cannot filter a query once a slice has been taken.")
clone = self._chain()
if self._defer_next_filter:
self._defer_next_filter = False
clone._deferred_filter = negate, args, kwargs
else:
clone._filter_or_exclude_inplace(negate, args, kwargs)
return clone
def _filter_or_exclude_inplace(self, negate, args, kwargs):
if negate:
self._query.add_q(~Q(*args, **kwargs))
else:
self._query.add_q(Q(*args, **kwargs))
def complex_filter(self, filter_obj):
"""
Return a new QuerySet instance with filter_obj added to the filters.
filter_obj can be a Q object or a dictionary of keyword lookup
arguments.
This exists to support framework features such as 'limit_choices_to',
and usually it will be more natural to use other methods.
"""
if isinstance(filter_obj, Q):
clone = self._chain()
clone.query.add_q(filter_obj)
return clone
else:
return self._filter_or_exclude(False, args=(), kwargs=filter_obj)
def _combinator_query(self, combinator, *other_qs, all=False):
# Clone the query to inherit the select list and everything
clone = self._chain()
# Clear limits and ordering so they can be reapplied
clone.query.clear_ordering(force=True)
clone.query.clear_limits()
clone.query.combined_queries = (self.query,) + tuple(
qs.query for qs in other_qs
)
clone.query.combinator = combinator
clone.query.combinator_all = all
return clone
def union(self, *other_qs, all=False):
# If the query is an EmptyQuerySet, combine all nonempty querysets.
if isinstance(self, EmptyQuerySet):
qs = [q for q in other_qs if not isinstance(q, EmptyQuerySet)]
if not qs:
return self
if len(qs) == 1:
return qs[0]
return qs[0]._combinator_query("union", *qs[1:], all=all)
return self._combinator_query("union", *other_qs, all=all)
def intersection(self, *other_qs):
# If any query is an EmptyQuerySet, return it.
if isinstance(self, EmptyQuerySet):
return self
for other in other_qs:
if isinstance(other, EmptyQuerySet):
return other
return self._combinator_query("intersection", *other_qs)
def difference(self, *other_qs):
# If the query is an EmptyQuerySet, return it.
if isinstance(self, EmptyQuerySet):
return self
return self._combinator_query("difference", *other_qs)
def select_for_update(self, nowait=False, skip_locked=False, of=(), no_key=False):
"""
Return a new QuerySet instance that will select objects with a
FOR UPDATE lock.
"""
if nowait and skip_locked:
raise ValueError("The nowait option cannot be used with skip_locked.")
obj = self._chain()
obj._for_write = True
obj.query.select_for_update = True
obj.query.select_for_update_nowait = nowait
obj.query.select_for_update_skip_locked = skip_locked
obj.query.select_for_update_of = of
obj.query.select_for_no_key_update = no_key
return obj
def select_related(self, *fields):
"""
Return a new QuerySet instance that will select related objects.
If fields are specified, they must be ForeignKey fields and only those
related objects are included in the selection.
If select_related(None) is called, clear the list.
"""
self._not_support_combined_queries("select_related")
if self._fields is not None:
raise TypeError(
"Cannot call select_related() after .values() or .values_list()"
)
obj = self._chain()
if fields == (None,):
obj.query.select_related = False
elif fields:
obj.query.add_select_related(fields)
else:
obj.query.select_related = True
return obj
def prefetch_related(self, *lookups):
"""
Return a new QuerySet instance that will prefetch the specified
Many-To-One and Many-To-Many related objects when the QuerySet is
evaluated.
When prefetch_related() is called more than once, append to the list of
prefetch lookups. If prefetch_related(None) is called, clear the list.
"""
self._not_support_combined_queries("prefetch_related")
clone = self._chain()
if lookups == (None,):
clone._prefetch_related_lookups = ()
else:
for lookup in lookups:
if isinstance(lookup, Prefetch):
lookup = lookup.prefetch_to
lookup = lookup.split(LOOKUP_SEP, 1)[0]
if lookup in self.query._filtered_relations:
raise ValueError(
"prefetch_related() is not supported with FilteredRelation."
)
clone._prefetch_related_lookups = clone._prefetch_related_lookups + lookups
return clone
def annotate(self, *args, **kwargs):
"""
Return a query set in which the returned objects have been annotated
with extra data or aggregations.
"""
self._not_support_combined_queries("annotate")
return self._annotate(args, kwargs, select=True)
def alias(self, *args, **kwargs):
"""
Return a query set with added aliases for extra data or aggregations.
"""
self._not_support_combined_queries("alias")
return self._annotate(args, kwargs, select=False)
def _annotate(self, args, kwargs, select=True):
self._validate_values_are_expressions(
args + tuple(kwargs.values()), method_name="annotate"
)
annotations = {}
for arg in args:
# The default_alias property may raise a TypeError.
try:
if arg.default_alias in kwargs:
raise ValueError(
"The named annotation '%s' conflicts with the "
"default name for another annotation." % arg.default_alias
)
except TypeError:
raise TypeError("Complex annotations require an alias")
annotations[arg.default_alias] = arg
annotations.update(kwargs)
clone = self._chain()
names = self._fields
if names is None:
names = set(
chain.from_iterable(
(field.name, field.attname)
if hasattr(field, "attname")
else (field.name,)
for field in self.model._meta.get_fields()
)
)
for alias, annotation in annotations.items():
if alias in names:
raise ValueError(
"The annotation '%s' conflicts with a field on "
"the model." % alias
)
if isinstance(annotation, FilteredRelation):
clone.query.add_filtered_relation(annotation, alias)
else:
clone.query.add_annotation(
annotation,
alias,
select=select,
)
for alias, annotation in clone.query.annotations.items():
if alias in annotations and annotation.contains_aggregate:
if clone._fields is None:
clone.query.group_by = True
else:
clone.query.set_group_by()
break
return clone
def order_by(self, *field_names):
"""Return a new QuerySet instance with the ordering changed."""
if self.query.is_sliced:
raise TypeError("Cannot reorder a query once a slice has been taken.")
obj = self._chain()
obj.query.clear_ordering(force=True, clear_default=False)
obj.query.add_ordering(*field_names)
return obj
def distinct(self, *field_names):
"""
Return a new QuerySet instance that will select only distinct results.
"""
self._not_support_combined_queries("distinct")
if self.query.is_sliced:
raise TypeError(
"Cannot create distinct fields once a slice has been taken."
)
obj = self._chain()
obj.query.add_distinct_fields(*field_names)
return obj
def extra(
self,
select=None,
where=None,
params=None,
tables=None,
order_by=None,
select_params=None,
):
"""Add extra SQL fragments to the query."""
self._not_support_combined_queries("extra")
if self.query.is_sliced:
raise TypeError("Cannot change a query once a slice has been taken.")
clone = self._chain()
clone.query.add_extra(select, select_params, where, params, tables, order_by)
return clone
def reverse(self):
"""Reverse the ordering of the QuerySet."""
if self.query.is_sliced:
raise TypeError("Cannot reverse a query once a slice has been taken.")
clone = self._chain()
clone.query.standard_ordering = not clone.query.standard_ordering
return clone
def defer(self, *fields):
"""
Defer the loading of data for certain fields until they are accessed.
Add the set of deferred fields to any existing set of deferred fields.
The only exception to this is if None is passed in as the only
parameter, in which case removal all deferrals.
"""
self._not_support_combined_queries("defer")
if self._fields is not None:
raise TypeError("Cannot call defer() after .values() or .values_list()")
clone = self._chain()
if fields == (None,):
clone.query.clear_deferred_loading()
else:
clone.query.add_deferred_loading(fields)
return clone
def only(self, *fields):
"""
Essentially, the opposite of defer(). Only the fields passed into this
method and that are not already specified as deferred are loaded
immediately when the queryset is evaluated.
"""
self._not_support_combined_queries("only")
if self._fields is not None:
raise TypeError("Cannot call only() after .values() or .values_list()")
if fields == (None,):
# Can only pass None to defer(), not only(), as the rest option.
# That won't stop people trying to do this, so let's be explicit.
raise TypeError("Cannot pass None as an argument to only().")
for field in fields:
field = field.split(LOOKUP_SEP, 1)[0]
if field in self.query._filtered_relations:
raise ValueError("only() is not supported with FilteredRelation.")
clone = self._chain()
clone.query.add_immediate_loading(fields)
return clone
def using(self, alias):
"""Select which database this QuerySet should execute against."""
clone = self._chain()
clone._db = alias
return clone
###################################
# PUBLIC INTROSPECTION ATTRIBUTES #
###################################
@property
def ordered(self):
"""
Return True if the QuerySet is ordered -- i.e. has an order_by()
clause or a default ordering on the model (or is empty).
"""
if isinstance(self, EmptyQuerySet):
return True
if self.query.extra_order_by or self.query.order_by:
return True
elif (
self.query.default_ordering
and self.query.get_meta().ordering
and
# A default ordering doesn't affect GROUP BY queries.
not self.query.group_by
):
return True
else:
return False
@property
def db(self):
"""Return the database used if this query is executed now."""
if self._for_write:
return self._db or router.db_for_write(self.model, **self._hints)
return self._db or router.db_for_read(self.model, **self._hints)
###################
# PRIVATE METHODS #
###################
def _insert(
self,
objs,
fields,
returning_fields=None,
raw=False,
using=None,
on_conflict=None,
update_fields=None,
unique_fields=None,
):
"""
Insert a new record for the given model. This provides an interface to
the InsertQuery class and is how Model.save() is implemented.
"""
self._for_write = True
if using is None:
using = self.db
query = sql.InsertQuery(
self.model,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
)
query.insert_values(fields, objs, raw=raw)
return query.get_compiler(using=using).execute_sql(returning_fields)
_insert.alters_data = True
_insert.queryset_only = False
def _batched_insert(
self,
objs,
fields,
batch_size,
on_conflict=None,
update_fields=None,
unique_fields=None,
):
"""
Helper method for bulk_create() to insert objs one batch at a time.
"""
connection = connections[self.db]
ops = connection.ops
max_batch_size = max(ops.bulk_batch_size(fields, objs), 1)
batch_size = min(batch_size, max_batch_size) if batch_size else max_batch_size
inserted_rows = []
bulk_return = connection.features.can_return_rows_from_bulk_insert
for item in [objs[i : i + batch_size] for i in range(0, len(objs), batch_size)]:
if bulk_return and on_conflict is None:
inserted_rows.extend(
self._insert(
item,
fields=fields,
using=self.db,
returning_fields=self.model._meta.db_returning_fields,
)
)
else:
self._insert(
item,
fields=fields,
using=self.db,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
)
return inserted_rows
def _chain(self):
"""
Return a copy of the current QuerySet that's ready for another
operation.
"""
obj = self._clone()
if obj._sticky_filter:
obj.query.filter_is_sticky = True
obj._sticky_filter = False
return obj
def _clone(self):
"""
Return a copy of the current QuerySet. A lightweight alternative
to deepcopy().
"""
c = self.__class__(
model=self.model,
query=self.query.chain(),
using=self._db,
hints=self._hints,
)
c._sticky_filter = self._sticky_filter
c._for_write = self._for_write
c._prefetch_related_lookups = self._prefetch_related_lookups[:]
c._known_related_objects = self._known_related_objects
c._iterable_class = self._iterable_class
c._fields = self._fields
return c
def _fetch_all(self):
if self._result_cache is None:
self._result_cache = list(self._iterable_class(self))
if self._prefetch_related_lookups and not self._prefetch_done:
self._prefetch_related_objects()
def _next_is_sticky(self):
"""
Indicate that the next filter call and the one following that should
be treated as a single filter. This is only important when it comes to
determining when to reuse tables for many-to-many filters. Required so
that we can filter naturally on the results of related managers.
This doesn't return a clone of the current QuerySet (it returns
"self"). The method is only used internally and should be immediately
followed by a filter() that does create a clone.
"""
self._sticky_filter = True
return self
def _merge_sanity_check(self, other):
"""Check that two QuerySet classes may be merged."""
if self._fields is not None and (
set(self.query.values_select) != set(other.query.values_select)
or set(self.query.extra_select) != set(other.query.extra_select)
or set(self.query.annotation_select) != set(other.query.annotation_select)
):
raise TypeError(
"Merging '%s' classes must involve the same values in each case."
% self.__class__.__name__
)
def _merge_known_related_objects(self, other):
"""
Keep track of all known related objects from either QuerySet instance.
"""
for field, objects in other._known_related_objects.items():
self._known_related_objects.setdefault(field, {}).update(objects)
def resolve_expression(self, *args, **kwargs):
if self._fields and len(self._fields) > 1:
# values() queryset can only be used as nested queries
# if they are set up to select only a single field.
raise TypeError("Cannot use multi-field values as a filter value.")
query = self.query.resolve_expression(*args, **kwargs)
query._db = self._db
return query
resolve_expression.queryset_only = True
def _add_hints(self, **hints):
"""
Update hinting information for use by routers. Add new key/values or
overwrite existing key/values.
"""
self._hints.update(hints)
def _has_filters(self):
"""
Check if this QuerySet has any filtering going on. This isn't
equivalent with checking if all objects are present in results, for
example, qs[1:]._has_filters() -> False.
"""
return self.query.has_filters()
@staticmethod
def _validate_values_are_expressions(values, method_name):
invalid_args = sorted(
str(arg) for arg in values if not hasattr(arg, "resolve_expression")
)
if invalid_args:
raise TypeError(
"QuerySet.%s() received non-expression(s): %s."
% (
method_name,
", ".join(invalid_args),
)
)
def _not_support_combined_queries(self, operation_name):
if self.query.combinator:
raise NotSupportedError(
"Calling QuerySet.%s() after %s() is not supported."
% (operation_name, self.query.combinator)
)
def _check_operator_queryset(self, other, operator_):
if self.query.combinator or other.query.combinator:
raise TypeError(f"Cannot use {operator_} operator with combined queryset.")
def _check_ordering_first_last_queryset_aggregation(self, method):
if isinstance(self.query.group_by, tuple) and not any(
col.output_field is self.model._meta.pk for col in self.query.group_by
):
raise TypeError(
f"Cannot use QuerySet.{method}() on an unordered queryset performing "
f"aggregation. Add an ordering with order_by()."
)
class InstanceCheckMeta(type):
def __instancecheck__(self, instance):
return isinstance(instance, QuerySet) and instance.query.is_empty()
class EmptyQuerySet(metaclass=InstanceCheckMeta):
"""
Marker class to checking if a queryset is empty by .none():
isinstance(qs.none(), EmptyQuerySet) -> True
"""
def __init__(self, *args, **kwargs):
raise TypeError("EmptyQuerySet can't be instantiated")
class RawQuerySet:
"""
Provide an iterator which converts the results of raw SQL queries into
annotated model instances.
"""
def __init__(
self,
raw_query,
model=None,
query=None,
params=(),
translations=None,
using=None,
hints=None,
):
self.raw_query = raw_query
self.model = model
self._db = using
self._hints = hints or {}
self.query = query or sql.RawQuery(sql=raw_query, using=self.db, params=params)
self.params = params
self.translations = translations or {}
self._result_cache = None
self._prefetch_related_lookups = ()
self._prefetch_done = False
def resolve_model_init_order(self):
"""Resolve the init field names and value positions."""
converter = connections[self.db].introspection.identifier_converter
model_init_fields = [
f for f in self.model._meta.fields if converter(f.column) in self.columns
]
annotation_fields = [
(column, pos)
for pos, column in enumerate(self.columns)
if column not in self.model_fields
]
model_init_order = [
self.columns.index(converter(f.column)) for f in model_init_fields
]
model_init_names = [f.attname for f in model_init_fields]
return model_init_names, model_init_order, annotation_fields
def prefetch_related(self, *lookups):
"""Same as QuerySet.prefetch_related()"""
clone = self._clone()
if lookups == (None,):
clone._prefetch_related_lookups = ()
else:
clone._prefetch_related_lookups = clone._prefetch_related_lookups + lookups
return clone
def _prefetch_related_objects(self):
prefetch_related_objects(self._result_cache, *self._prefetch_related_lookups)
self._prefetch_done = True
def _clone(self):
"""Same as QuerySet._clone()"""
c = self.__class__(
self.raw_query,
model=self.model,
query=self.query,
params=self.params,
translations=self.translations,
using=self._db,
hints=self._hints,
)
c._prefetch_related_lookups = self._prefetch_related_lookups[:]
return c
def _fetch_all(self):
if self._result_cache is None:
self._result_cache = list(self.iterator())
if self._prefetch_related_lookups and not self._prefetch_done:
self._prefetch_related_objects()
def __len__(self):
self._fetch_all()
return len(self._result_cache)
def __bool__(self):
self._fetch_all()
return bool(self._result_cache)
def __iter__(self):
self._fetch_all()
return iter(self._result_cache)
def __aiter__(self):
# Remember, __aiter__ itself is synchronous, it's the thing it returns
# that is async!
async def generator():
await sync_to_async(self._fetch_all)()
for item in self._result_cache:
yield item
return generator()
def iterator(self):
yield from RawModelIterable(self)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self.query)
def __getitem__(self, k):
return list(self)[k]
@property
def db(self):
"""Return the database used if this query is executed now."""
return self._db or router.db_for_read(self.model, **self._hints)
def using(self, alias):
"""Select the database this RawQuerySet should execute against."""
return RawQuerySet(
self.raw_query,
model=self.model,
query=self.query.chain(using=alias),
params=self.params,
translations=self.translations,
using=alias,
)
@cached_property
def columns(self):
"""
A list of model field names in the order they'll appear in the
query results.
"""
columns = self.query.get_columns()
# Adjust any column names which don't match field names
for query_name, model_name in self.translations.items():
# Ignore translations for nonexistent column names
try:
index = columns.index(query_name)
except ValueError:
pass
else:
columns[index] = model_name
return columns
@cached_property
def model_fields(self):
"""A dict mapping column names to model field names."""
converter = connections[self.db].introspection.identifier_converter
model_fields = {}
for field in self.model._meta.fields:
name, column = field.get_attname_column()
model_fields[converter(column)] = field
return model_fields
class Prefetch:
def __init__(self, lookup, queryset=None, to_attr=None):
# `prefetch_through` is the path we traverse to perform the prefetch.
self.prefetch_through = lookup
# `prefetch_to` is the path to the attribute that stores the result.
self.prefetch_to = lookup
if queryset is not None and (
isinstance(queryset, RawQuerySet)
or (
hasattr(queryset, "_iterable_class")
and not issubclass(queryset._iterable_class, ModelIterable)
)
):
raise ValueError(
"Prefetch querysets cannot use raw(), values(), and values_list()."
)
if to_attr:
self.prefetch_to = LOOKUP_SEP.join(
lookup.split(LOOKUP_SEP)[:-1] + [to_attr]
)
self.queryset = queryset
self.to_attr = to_attr
def __getstate__(self):
obj_dict = self.__dict__.copy()
if self.queryset is not None:
queryset = self.queryset._chain()
# Prevent the QuerySet from being evaluated
queryset._result_cache = []
queryset._prefetch_done = True
obj_dict["queryset"] = queryset
return obj_dict
def add_prefix(self, prefix):
self.prefetch_through = prefix + LOOKUP_SEP + self.prefetch_through
self.prefetch_to = prefix + LOOKUP_SEP + self.prefetch_to
def get_current_prefetch_to(self, level):
return LOOKUP_SEP.join(self.prefetch_to.split(LOOKUP_SEP)[: level + 1])
def get_current_to_attr(self, level):
parts = self.prefetch_to.split(LOOKUP_SEP)
to_attr = parts[level]
as_attr = self.to_attr and level == len(parts) - 1
return to_attr, as_attr
def get_current_queryset(self, level):
if self.get_current_prefetch_to(level) == self.prefetch_to:
return self.queryset
return None
def __eq__(self, other):
if not isinstance(other, Prefetch):
return NotImplemented
return self.prefetch_to == other.prefetch_to
def __hash__(self):
return hash((self.__class__, self.prefetch_to))
def normalize_prefetch_lookups(lookups, prefix=None):
"""Normalize lookups into Prefetch objects."""
ret = []
for lookup in lookups:
if not isinstance(lookup, Prefetch):
lookup = Prefetch(lookup)
if prefix:
lookup.add_prefix(prefix)
ret.append(lookup)
return ret
def prefetch_related_objects(model_instances, *related_lookups):
"""
Populate prefetched object caches for a list of model instances based on
the lookups/Prefetch instances given.
"""
if not model_instances:
return # nothing to do
# We need to be able to dynamically add to the list of prefetch_related
# lookups that we look up (see below). So we need some book keeping to
# ensure we don't do duplicate work.
done_queries = {} # dictionary of things like 'foo__bar': [results]
auto_lookups = set() # we add to this as we go through.
followed_descriptors = set() # recursion protection
all_lookups = normalize_prefetch_lookups(reversed(related_lookups))
while all_lookups:
lookup = all_lookups.pop()
if lookup.prefetch_to in done_queries:
if lookup.queryset is not None:
raise ValueError(
"'%s' lookup was already seen with a different queryset. "
"You may need to adjust the ordering of your lookups."
% lookup.prefetch_to
)
continue
# Top level, the list of objects to decorate is the result cache
# from the primary QuerySet. It won't be for deeper levels.
obj_list = model_instances
through_attrs = lookup.prefetch_through.split(LOOKUP_SEP)
for level, through_attr in enumerate(through_attrs):
# Prepare main instances
if not obj_list:
break
prefetch_to = lookup.get_current_prefetch_to(level)
if prefetch_to in done_queries:
# Skip any prefetching, and any object preparation
obj_list = done_queries[prefetch_to]
continue
# Prepare objects:
good_objects = True
for obj in obj_list:
# Since prefetching can re-use instances, it is possible to have
# the same instance multiple times in obj_list, so obj might
# already be prepared.
if not hasattr(obj, "_prefetched_objects_cache"):
try:
obj._prefetched_objects_cache = {}
except (AttributeError, TypeError):
# Must be an immutable object from
# values_list(flat=True), for example (TypeError) or
# a QuerySet subclass that isn't returning Model
# instances (AttributeError), either in Django or a 3rd
# party. prefetch_related() doesn't make sense, so quit.
good_objects = False
break
if not good_objects:
break
# Descend down tree
# We assume that objects retrieved are homogeneous (which is the premise
# of prefetch_related), so what applies to first object applies to all.
first_obj = obj_list[0]
to_attr = lookup.get_current_to_attr(level)[0]
prefetcher, descriptor, attr_found, is_fetched = get_prefetcher(
first_obj, through_attr, to_attr
)
if not attr_found:
raise AttributeError(
"Cannot find '%s' on %s object, '%s' is an invalid "
"parameter to prefetch_related()"
% (
through_attr,
first_obj.__class__.__name__,
lookup.prefetch_through,
)
)
if level == len(through_attrs) - 1 and prefetcher is None:
# Last one, this *must* resolve to something that supports
# prefetching, otherwise there is no point adding it and the
# developer asking for it has made a mistake.
raise ValueError(
"'%s' does not resolve to an item that supports "
"prefetching - this is an invalid parameter to "
"prefetch_related()." % lookup.prefetch_through
)
obj_to_fetch = None
if prefetcher is not None:
obj_to_fetch = [obj for obj in obj_list if not is_fetched(obj)]
if obj_to_fetch:
obj_list, additional_lookups = prefetch_one_level(
obj_to_fetch,
prefetcher,
lookup,
level,
)
# We need to ensure we don't keep adding lookups from the
# same relationships to stop infinite recursion. So, if we
# are already on an automatically added lookup, don't add
# the new lookups from relationships we've seen already.
if not (
prefetch_to in done_queries
and lookup in auto_lookups
and descriptor in followed_descriptors
):
done_queries[prefetch_to] = obj_list
new_lookups = normalize_prefetch_lookups(
reversed(additional_lookups), prefetch_to
)
auto_lookups.update(new_lookups)
all_lookups.extend(new_lookups)
followed_descriptors.add(descriptor)
else:
# Either a singly related object that has already been fetched
# (e.g. via select_related), or hopefully some other property
# that doesn't support prefetching but needs to be traversed.
# We replace the current list of parent objects with the list
# of related objects, filtering out empty or missing values so
# that we can continue with nullable or reverse relations.
new_obj_list = []
for obj in obj_list:
if through_attr in getattr(obj, "_prefetched_objects_cache", ()):
# If related objects have been prefetched, use the
# cache rather than the object's through_attr.
new_obj = list(obj._prefetched_objects_cache.get(through_attr))
else:
try:
new_obj = getattr(obj, through_attr)
except exceptions.ObjectDoesNotExist:
continue
if new_obj is None:
continue
# We special-case `list` rather than something more generic
# like `Iterable` because we don't want to accidentally match
# user models that define __iter__.
if isinstance(new_obj, list):
new_obj_list.extend(new_obj)
else:
new_obj_list.append(new_obj)
obj_list = new_obj_list
def get_prefetcher(instance, through_attr, to_attr):
"""
For the attribute 'through_attr' on the given instance, find
an object that has a get_prefetch_queryset().
Return a 4 tuple containing:
(the object with get_prefetch_queryset (or None),
the descriptor object representing this relationship (or None),
a boolean that is False if the attribute was not found at all,
a function that takes an instance and returns a boolean that is True if
the attribute has already been fetched for that instance)
"""
def has_to_attr_attribute(instance):
return hasattr(instance, to_attr)
prefetcher = None
is_fetched = has_to_attr_attribute
# For singly related objects, we have to avoid getting the attribute
# from the object, as this will trigger the query. So we first try
# on the class, in order to get the descriptor object.
rel_obj_descriptor = getattr(instance.__class__, through_attr, None)
if rel_obj_descriptor is None:
attr_found = hasattr(instance, through_attr)
else:
attr_found = True
if rel_obj_descriptor:
# singly related object, descriptor object has the
# get_prefetch_queryset() method.
if hasattr(rel_obj_descriptor, "get_prefetch_queryset"):
prefetcher = rel_obj_descriptor
is_fetched = rel_obj_descriptor.is_cached
else:
# descriptor doesn't support prefetching, so we go ahead and get
# the attribute on the instance rather than the class to
# support many related managers
rel_obj = getattr(instance, through_attr)
if hasattr(rel_obj, "get_prefetch_queryset"):
prefetcher = rel_obj
if through_attr != to_attr:
# Special case cached_property instances because hasattr
# triggers attribute computation and assignment.
if isinstance(
getattr(instance.__class__, to_attr, None), cached_property
):
def has_cached_property(instance):
return to_attr in instance.__dict__
is_fetched = has_cached_property
else:
def in_prefetched_cache(instance):
return through_attr in instance._prefetched_objects_cache
is_fetched = in_prefetched_cache
return prefetcher, rel_obj_descriptor, attr_found, is_fetched
def prefetch_one_level(instances, prefetcher, lookup, level):
"""
Helper function for prefetch_related_objects().
Run prefetches on all instances using the prefetcher object,
assigning results to relevant caches in instance.
Return the prefetched objects along with any additional prefetches that
must be done due to prefetch_related lookups found from default managers.
"""
# prefetcher must have a method get_prefetch_queryset() which takes a list
# of instances, and returns a tuple:
# (queryset of instances of self.model that are related to passed in instances,
# callable that gets value to be matched for returned instances,
# callable that gets value to be matched for passed in instances,
# boolean that is True for singly related objects,
# cache or field name to assign to,
# boolean that is True when the previous argument is a cache name vs a field name).
# The 'values to be matched' must be hashable as they will be used
# in a dictionary.
(
rel_qs,
rel_obj_attr,
instance_attr,
single,
cache_name,
is_descriptor,
) = prefetcher.get_prefetch_queryset(instances, lookup.get_current_queryset(level))
# We have to handle the possibility that the QuerySet we just got back
# contains some prefetch_related lookups. We don't want to trigger the
# prefetch_related functionality by evaluating the query. Rather, we need
# to merge in the prefetch_related lookups.
# Copy the lookups in case it is a Prefetch object which could be reused
# later (happens in nested prefetch_related).
additional_lookups = [
copy.copy(additional_lookup)
for additional_lookup in getattr(rel_qs, "_prefetch_related_lookups", ())
]
if additional_lookups:
# Don't need to clone because the manager should have given us a fresh
# instance, so we access an internal instead of using public interface
# for performance reasons.
rel_qs._prefetch_related_lookups = ()
all_related_objects = list(rel_qs)
rel_obj_cache = {}
for rel_obj in all_related_objects:
rel_attr_val = rel_obj_attr(rel_obj)
rel_obj_cache.setdefault(rel_attr_val, []).append(rel_obj)
to_attr, as_attr = lookup.get_current_to_attr(level)
# Make sure `to_attr` does not conflict with a field.
if as_attr and instances:
# We assume that objects retrieved are homogeneous (which is the premise
# of prefetch_related), so what applies to first object applies to all.
model = instances[0].__class__
try:
model._meta.get_field(to_attr)
except exceptions.FieldDoesNotExist:
pass
else:
msg = "to_attr={} conflicts with a field on the {} model."
raise ValueError(msg.format(to_attr, model.__name__))
# Whether or not we're prefetching the last part of the lookup.
leaf = len(lookup.prefetch_through.split(LOOKUP_SEP)) - 1 == level
for obj in instances:
instance_attr_val = instance_attr(obj)
vals = rel_obj_cache.get(instance_attr_val, [])
if single:
val = vals[0] if vals else None
if as_attr:
# A to_attr has been given for the prefetch.
setattr(obj, to_attr, val)
elif is_descriptor:
# cache_name points to a field name in obj.
# This field is a descriptor for a related object.
setattr(obj, cache_name, val)
else:
# No to_attr has been given for this prefetch operation and the
# cache_name does not point to a descriptor. Store the value of
# the field in the object's field cache.
obj._state.fields_cache[cache_name] = val
else:
if as_attr:
setattr(obj, to_attr, vals)
else:
manager = getattr(obj, to_attr)
if leaf and lookup.queryset is not None:
qs = manager._apply_rel_filters(lookup.queryset)
else:
qs = manager.get_queryset()
qs._result_cache = vals
# We don't want the individual qs doing prefetch_related now,
# since we have merged this into the current work.
qs._prefetch_done = True
obj._prefetched_objects_cache[cache_name] = qs
return all_related_objects, additional_lookups
class RelatedPopulator:
"""
RelatedPopulator is used for select_related() object instantiation.
The idea is that each select_related() model will be populated by a
different RelatedPopulator instance. The RelatedPopulator instances get
klass_info and select (computed in SQLCompiler) plus the used db as
input for initialization. That data is used to compute which columns
to use, how to instantiate the model, and how to populate the links
between the objects.
The actual creation of the objects is done in populate() method. This
method gets row and from_obj as input and populates the select_related()
model instance.
"""
def __init__(self, klass_info, select, db):
self.db = db
# Pre-compute needed attributes. The attributes are:
# - model_cls: the possibly deferred model class to instantiate
# - either:
# - cols_start, cols_end: usually the columns in the row are
# in the same order model_cls.__init__ expects them, so we
# can instantiate by model_cls(*row[cols_start:cols_end])
# - reorder_for_init: When select_related descends to a child
# class, then we want to reuse the already selected parent
# data. However, in this case the parent data isn't necessarily
# in the same order that Model.__init__ expects it to be, so
# we have to reorder the parent data. The reorder_for_init
# attribute contains a function used to reorder the field data
# in the order __init__ expects it.
# - pk_idx: the index of the primary key field in the reordered
# model data. Used to check if a related object exists at all.
# - init_list: the field attnames fetched from the database. For
# deferred models this isn't the same as all attnames of the
# model's fields.
# - related_populators: a list of RelatedPopulator instances if
# select_related() descends to related models from this model.
# - local_setter, remote_setter: Methods to set cached values on
# the object being populated and on the remote object. Usually
# these are Field.set_cached_value() methods.
select_fields = klass_info["select_fields"]
from_parent = klass_info["from_parent"]
if not from_parent:
self.cols_start = select_fields[0]
self.cols_end = select_fields[-1] + 1
self.init_list = [
f[0].target.attname for f in select[self.cols_start : self.cols_end]
]
self.reorder_for_init = None
else:
attname_indexes = {
select[idx][0].target.attname: idx for idx in select_fields
}
model_init_attnames = (
f.attname for f in klass_info["model"]._meta.concrete_fields
)
self.init_list = [
attname for attname in model_init_attnames if attname in attname_indexes
]
self.reorder_for_init = operator.itemgetter(
*[attname_indexes[attname] for attname in self.init_list]
)
self.model_cls = klass_info["model"]
self.pk_idx = self.init_list.index(self.model_cls._meta.pk.attname)
self.related_populators = get_related_populators(klass_info, select, self.db)
self.local_setter = klass_info["local_setter"]
self.remote_setter = klass_info["remote_setter"]
def populate(self, row, from_obj):
if self.reorder_for_init:
obj_data = self.reorder_for_init(row)
else:
obj_data = row[self.cols_start : self.cols_end]
if obj_data[self.pk_idx] is None:
obj = None
else:
obj = self.model_cls.from_db(self.db, self.init_list, obj_data)
for rel_iter in self.related_populators:
rel_iter.populate(row, obj)
self.local_setter(from_obj, obj)
if obj is not None:
self.remote_setter(obj, from_obj)
def get_related_populators(klass_info, select, db):
iterators = []
related_klass_infos = klass_info.get("related_klass_infos", [])
for rel_klass_info in related_klass_infos:
rel_cls = RelatedPopulator(rel_klass_info, select, db)
iterators.append(rel_cls)
return iterators
|
castiel248/Convert
|
Lib/site-packages/django/db/models/query.py
|
Python
|
mit
| 101,762 |
"""
Various data structures used in query construction.
Factored out from django.db.models.query to avoid making the main module very
large and/or so that they can be used by other modules without getting into
circular import difficulties.
"""
import functools
import inspect
import logging
from collections import namedtuple
from django.core.exceptions import FieldError
from django.db import DEFAULT_DB_ALIAS, DatabaseError, connections
from django.db.models.constants import LOOKUP_SEP
from django.utils import tree
logger = logging.getLogger("django.db.models")
# PathInfo is used when converting lookups (fk__somecol). The contents
# describe the relation in Model terms (model Options and Fields for both
# sides of the relation. The join_field is the field backing the relation.
PathInfo = namedtuple(
"PathInfo",
"from_opts to_opts target_fields join_field m2m direct filtered_relation",
)
def subclasses(cls):
yield cls
for subclass in cls.__subclasses__():
yield from subclasses(subclass)
class Q(tree.Node):
"""
Encapsulate filters as objects that can then be combined logically (using
`&` and `|`).
"""
# Connection types
AND = "AND"
OR = "OR"
XOR = "XOR"
default = AND
conditional = True
def __init__(self, *args, _connector=None, _negated=False, **kwargs):
super().__init__(
children=[*args, *sorted(kwargs.items())],
connector=_connector,
negated=_negated,
)
def _combine(self, other, conn):
if getattr(other, "conditional", False) is False:
raise TypeError(other)
if not self:
return other.copy()
if not other and isinstance(other, Q):
return self.copy()
obj = self.create(connector=conn)
obj.add(self, conn)
obj.add(other, conn)
return obj
def __or__(self, other):
return self._combine(other, self.OR)
def __and__(self, other):
return self._combine(other, self.AND)
def __xor__(self, other):
return self._combine(other, self.XOR)
def __invert__(self):
obj = self.copy()
obj.negate()
return obj
def resolve_expression(
self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False
):
# We must promote any new joins to left outer joins so that when Q is
# used as an expression, rows aren't filtered due to joins.
clause, joins = query._add_q(
self,
reuse,
allow_joins=allow_joins,
split_subq=False,
check_filterable=False,
summarize=summarize,
)
query.promote_joins(joins)
return clause
def flatten(self):
"""
Recursively yield this Q object and all subexpressions, in depth-first
order.
"""
yield self
for child in self.children:
if isinstance(child, tuple):
# Use the lookup.
child = child[1]
if hasattr(child, "flatten"):
yield from child.flatten()
else:
yield child
def check(self, against, using=DEFAULT_DB_ALIAS):
"""
Do a database query to check if the expressions of the Q instance
matches against the expressions.
"""
# Avoid circular imports.
from django.db.models import BooleanField, Value
from django.db.models.functions import Coalesce
from django.db.models.sql import Query
from django.db.models.sql.constants import SINGLE
query = Query(None)
for name, value in against.items():
if not hasattr(value, "resolve_expression"):
value = Value(value)
query.add_annotation(value, name, select=False)
query.add_annotation(Value(1), "_check")
# This will raise a FieldError if a field is missing in "against".
if connections[using].features.supports_comparing_boolean_expr:
query.add_q(Q(Coalesce(self, True, output_field=BooleanField())))
else:
query.add_q(self)
compiler = query.get_compiler(using=using)
try:
return compiler.execute_sql(SINGLE) is not None
except DatabaseError as e:
logger.warning("Got a database error calling check() on %r: %s", self, e)
return True
def deconstruct(self):
path = "%s.%s" % (self.__class__.__module__, self.__class__.__name__)
if path.startswith("django.db.models.query_utils"):
path = path.replace("django.db.models.query_utils", "django.db.models")
args = tuple(self.children)
kwargs = {}
if self.connector != self.default:
kwargs["_connector"] = self.connector
if self.negated:
kwargs["_negated"] = True
return path, args, kwargs
class DeferredAttribute:
"""
A wrapper for a deferred-loading field. When the value is read from this
object the first time, the query is executed.
"""
def __init__(self, field):
self.field = field
def __get__(self, instance, cls=None):
"""
Retrieve and caches the value from the datastore on the first lookup.
Return the cached value.
"""
if instance is None:
return self
data = instance.__dict__
field_name = self.field.attname
if field_name not in data:
# Let's see if the field is part of the parent chain. If so we
# might be able to reuse the already loaded value. Refs #18343.
val = self._check_parent_chain(instance)
if val is None:
instance.refresh_from_db(fields=[field_name])
else:
data[field_name] = val
return data[field_name]
def _check_parent_chain(self, instance):
"""
Check if the field value can be fetched from a parent field already
loaded in the instance. This can be done if the to-be fetched
field is a primary key field.
"""
opts = instance._meta
link_field = opts.get_ancestor_link(self.field.model)
if self.field.primary_key and self.field != link_field:
return getattr(instance, link_field.attname)
return None
class class_or_instance_method:
"""
Hook used in RegisterLookupMixin to return partial functions depending on
the caller type (instance or class of models.Field).
"""
def __init__(self, class_method, instance_method):
self.class_method = class_method
self.instance_method = instance_method
def __get__(self, instance, owner):
if instance is None:
return functools.partial(self.class_method, owner)
return functools.partial(self.instance_method, instance)
class RegisterLookupMixin:
def _get_lookup(self, lookup_name):
return self.get_lookups().get(lookup_name, None)
@functools.lru_cache(maxsize=None)
def get_class_lookups(cls):
class_lookups = [
parent.__dict__.get("class_lookups", {}) for parent in inspect.getmro(cls)
]
return cls.merge_dicts(class_lookups)
def get_instance_lookups(self):
class_lookups = self.get_class_lookups()
if instance_lookups := getattr(self, "instance_lookups", None):
return {**class_lookups, **instance_lookups}
return class_lookups
get_lookups = class_or_instance_method(get_class_lookups, get_instance_lookups)
get_class_lookups = classmethod(get_class_lookups)
def get_lookup(self, lookup_name):
from django.db.models.lookups import Lookup
found = self._get_lookup(lookup_name)
if found is None and hasattr(self, "output_field"):
return self.output_field.get_lookup(lookup_name)
if found is not None and not issubclass(found, Lookup):
return None
return found
def get_transform(self, lookup_name):
from django.db.models.lookups import Transform
found = self._get_lookup(lookup_name)
if found is None and hasattr(self, "output_field"):
return self.output_field.get_transform(lookup_name)
if found is not None and not issubclass(found, Transform):
return None
return found
@staticmethod
def merge_dicts(dicts):
"""
Merge dicts in reverse to preference the order of the original list. e.g.,
merge_dicts([a, b]) will preference the keys in 'a' over those in 'b'.
"""
merged = {}
for d in reversed(dicts):
merged.update(d)
return merged
@classmethod
def _clear_cached_class_lookups(cls):
for subclass in subclasses(cls):
subclass.get_class_lookups.cache_clear()
def register_class_lookup(cls, lookup, lookup_name=None):
if lookup_name is None:
lookup_name = lookup.lookup_name
if "class_lookups" not in cls.__dict__:
cls.class_lookups = {}
cls.class_lookups[lookup_name] = lookup
cls._clear_cached_class_lookups()
return lookup
def register_instance_lookup(self, lookup, lookup_name=None):
if lookup_name is None:
lookup_name = lookup.lookup_name
if "instance_lookups" not in self.__dict__:
self.instance_lookups = {}
self.instance_lookups[lookup_name] = lookup
return lookup
register_lookup = class_or_instance_method(
register_class_lookup, register_instance_lookup
)
register_class_lookup = classmethod(register_class_lookup)
def _unregister_class_lookup(cls, lookup, lookup_name=None):
"""
Remove given lookup from cls lookups. For use in tests only as it's
not thread-safe.
"""
if lookup_name is None:
lookup_name = lookup.lookup_name
del cls.class_lookups[lookup_name]
cls._clear_cached_class_lookups()
def _unregister_instance_lookup(self, lookup, lookup_name=None):
"""
Remove given lookup from instance lookups. For use in tests only as
it's not thread-safe.
"""
if lookup_name is None:
lookup_name = lookup.lookup_name
del self.instance_lookups[lookup_name]
_unregister_lookup = class_or_instance_method(
_unregister_class_lookup, _unregister_instance_lookup
)
_unregister_class_lookup = classmethod(_unregister_class_lookup)
def select_related_descend(field, restricted, requested, select_mask, reverse=False):
"""
Return True if this field should be used to descend deeper for
select_related() purposes. Used by both the query construction code
(compiler.get_related_selections()) and the model instance creation code
(compiler.klass_info).
Arguments:
* field - the field to be checked
* restricted - a boolean field, indicating if the field list has been
manually restricted using a requested clause)
* requested - The select_related() dictionary.
* select_mask - the dictionary of selected fields.
* reverse - boolean, True if we are checking a reverse select related
"""
if not field.remote_field:
return False
if field.remote_field.parent_link and not reverse:
return False
if restricted:
if reverse and field.related_query_name() not in requested:
return False
if not reverse and field.name not in requested:
return False
if not restricted and field.null:
return False
if (
restricted
and select_mask
and field.name in requested
and field not in select_mask
):
raise FieldError(
f"Field {field.model._meta.object_name}.{field.name} cannot be both "
"deferred and traversed using select_related at the same time."
)
return True
def refs_expression(lookup_parts, annotations):
"""
Check if the lookup_parts contains references to the given annotations set.
Because the LOOKUP_SEP is contained in the default annotation names, check
each prefix of the lookup_parts for a match.
"""
for n in range(1, len(lookup_parts) + 1):
level_n_lookup = LOOKUP_SEP.join(lookup_parts[0:n])
if annotations.get(level_n_lookup):
return level_n_lookup, lookup_parts[n:]
return None, ()
def check_rel_lookup_compatibility(model, target_opts, field):
"""
Check that self.model is compatible with target_opts. Compatibility
is OK if:
1) model and opts match (where proxy inheritance is removed)
2) model is parent of opts' model or the other way around
"""
def check(opts):
return (
model._meta.concrete_model == opts.concrete_model
or opts.concrete_model in model._meta.get_parent_list()
or model in opts.get_parent_list()
)
# If the field is a primary key, then doing a query against the field's
# model is ok, too. Consider the case:
# class Restaurant(models.Model):
# place = OneToOneField(Place, primary_key=True):
# Restaurant.objects.filter(pk__in=Restaurant.objects.all()).
# If we didn't have the primary key check, then pk__in (== place__in) would
# give Place's opts as the target opts, but Restaurant isn't compatible
# with that. This logic applies only to primary keys, as when doing __in=qs,
# we are going to turn this into __in=qs.values('pk') later on.
return check(target_opts) or (
getattr(field, "primary_key", False) and check(field.model._meta)
)
class FilteredRelation:
"""Specify custom filtering in the ON clause of SQL joins."""
def __init__(self, relation_name, *, condition=Q()):
if not relation_name:
raise ValueError("relation_name cannot be empty.")
self.relation_name = relation_name
self.alias = None
if not isinstance(condition, Q):
raise ValueError("condition argument must be a Q() instance.")
self.condition = condition
self.path = []
def __eq__(self, other):
if not isinstance(other, self.__class__):
return NotImplemented
return (
self.relation_name == other.relation_name
and self.alias == other.alias
and self.condition == other.condition
)
def clone(self):
clone = FilteredRelation(self.relation_name, condition=self.condition)
clone.alias = self.alias
clone.path = self.path[:]
return clone
def resolve_expression(self, *args, **kwargs):
"""
QuerySet.annotate() only accepts expression-like arguments
(with a resolve_expression() method).
"""
raise NotImplementedError("FilteredRelation.resolve_expression() is unused.")
def as_sql(self, compiler, connection):
# Resolve the condition in Join.filtered_relation.
query = compiler.query
where = query.build_filtered_relation_q(self.condition, reuse=set(self.path))
return compiler.compile(where)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/query_utils.py
|
Python
|
mit
| 15,244 |
from functools import partial
from django.db.models.utils import make_model_tuple
from django.dispatch import Signal
class_prepared = Signal()
class ModelSignal(Signal):
"""
Signal subclass that allows the sender to be lazily specified as a string
of the `app_label.ModelName` form.
"""
def _lazy_method(self, method, apps, receiver, sender, **kwargs):
from django.db.models.options import Options
# This partial takes a single optional argument named "sender".
partial_method = partial(method, receiver, **kwargs)
if isinstance(sender, str):
apps = apps or Options.default_apps
apps.lazy_model_operation(partial_method, make_model_tuple(sender))
else:
return partial_method(sender)
def connect(self, receiver, sender=None, weak=True, dispatch_uid=None, apps=None):
self._lazy_method(
super().connect,
apps,
receiver,
sender,
weak=weak,
dispatch_uid=dispatch_uid,
)
def disconnect(self, receiver=None, sender=None, dispatch_uid=None, apps=None):
return self._lazy_method(
super().disconnect, apps, receiver, sender, dispatch_uid=dispatch_uid
)
pre_init = ModelSignal(use_caching=True)
post_init = ModelSignal(use_caching=True)
pre_save = ModelSignal(use_caching=True)
post_save = ModelSignal(use_caching=True)
pre_delete = ModelSignal(use_caching=True)
post_delete = ModelSignal(use_caching=True)
m2m_changed = ModelSignal(use_caching=True)
pre_migrate = Signal()
post_migrate = Signal()
|
castiel248/Convert
|
Lib/site-packages/django/db/models/signals.py
|
Python
|
mit
| 1,622 |
from django.db.models.sql.query import * # NOQA
from django.db.models.sql.query import Query
from django.db.models.sql.subqueries import * # NOQA
from django.db.models.sql.where import AND, OR, XOR
__all__ = ["Query", "AND", "OR", "XOR"]
|
castiel248/Convert
|
Lib/site-packages/django/db/models/sql/__init__.py
|
Python
|
mit
| 241 |
import collections
import json
import re
from functools import partial
from itertools import chain
from django.core.exceptions import EmptyResultSet, FieldError, FullResultSet
from django.db import DatabaseError, NotSupportedError
from django.db.models.constants import LOOKUP_SEP
from django.db.models.expressions import F, OrderBy, RawSQL, Ref, Value
from django.db.models.functions import Cast, Random
from django.db.models.lookups import Lookup
from django.db.models.query_utils import select_related_descend
from django.db.models.sql.constants import (
CURSOR,
GET_ITERATOR_CHUNK_SIZE,
MULTI,
NO_RESULTS,
ORDER_DIR,
SINGLE,
)
from django.db.models.sql.query import Query, get_order_dir
from django.db.models.sql.where import AND
from django.db.transaction import TransactionManagementError
from django.utils.functional import cached_property
from django.utils.hashable import make_hashable
from django.utils.regex_helper import _lazy_re_compile
class PositionRef(Ref):
def __init__(self, ordinal, refs, source):
self.ordinal = ordinal
super().__init__(refs, source)
def as_sql(self, compiler, connection):
return str(self.ordinal), ()
class SQLCompiler:
# Multiline ordering SQL clause may appear from RawSQL.
ordering_parts = _lazy_re_compile(
r"^(.*)\s(?:ASC|DESC).*",
re.MULTILINE | re.DOTALL,
)
def __init__(self, query, connection, using, elide_empty=True):
self.query = query
self.connection = connection
self.using = using
# Some queries, e.g. coalesced aggregation, need to be executed even if
# they would return an empty result set.
self.elide_empty = elide_empty
self.quote_cache = {"*": "*"}
# The select, klass_info, and annotations are needed by QuerySet.iterator()
# these are set as a side-effect of executing the query. Note that we calculate
# separately a list of extra select columns needed for grammatical correctness
# of the query, but these columns are not included in self.select.
self.select = None
self.annotation_col_map = None
self.klass_info = None
self._meta_ordering = None
def __repr__(self):
return (
f"<{self.__class__.__qualname__} "
f"model={self.query.model.__qualname__} "
f"connection={self.connection!r} using={self.using!r}>"
)
def setup_query(self, with_col_aliases=False):
if all(self.query.alias_refcount[a] == 0 for a in self.query.alias_map):
self.query.get_initial_alias()
self.select, self.klass_info, self.annotation_col_map = self.get_select(
with_col_aliases=with_col_aliases,
)
self.col_count = len(self.select)
def pre_sql_setup(self, with_col_aliases=False):
"""
Do any necessary class setup immediately prior to producing SQL. This
is for things that can't necessarily be done in __init__ because we
might not have all the pieces in place at that time.
"""
self.setup_query(with_col_aliases=with_col_aliases)
order_by = self.get_order_by()
self.where, self.having, self.qualify = self.query.where.split_having_qualify(
must_group_by=self.query.group_by is not None
)
extra_select = self.get_extra_select(order_by, self.select)
self.has_extra_select = bool(extra_select)
group_by = self.get_group_by(self.select + extra_select, order_by)
return extra_select, order_by, group_by
def get_group_by(self, select, order_by):
"""
Return a list of 2-tuples of form (sql, params).
The logic of what exactly the GROUP BY clause contains is hard
to describe in other words than "if it passes the test suite,
then it is correct".
"""
# Some examples:
# SomeModel.objects.annotate(Count('somecol'))
# GROUP BY: all fields of the model
#
# SomeModel.objects.values('name').annotate(Count('somecol'))
# GROUP BY: name
#
# SomeModel.objects.annotate(Count('somecol')).values('name')
# GROUP BY: all cols of the model
#
# SomeModel.objects.values('name', 'pk')
# .annotate(Count('somecol')).values('pk')
# GROUP BY: name, pk
#
# SomeModel.objects.values('name').annotate(Count('somecol')).values('pk')
# GROUP BY: name, pk
#
# In fact, the self.query.group_by is the minimal set to GROUP BY. It
# can't be ever restricted to a smaller set, but additional columns in
# HAVING, ORDER BY, and SELECT clauses are added to it. Unfortunately
# the end result is that it is impossible to force the query to have
# a chosen GROUP BY clause - you can almost do this by using the form:
# .values(*wanted_cols).annotate(AnAggregate())
# but any later annotations, extra selects, values calls that
# refer some column outside of the wanted_cols, order_by, or even
# filter calls can alter the GROUP BY clause.
# The query.group_by is either None (no GROUP BY at all), True
# (group by select fields), or a list of expressions to be added
# to the group by.
if self.query.group_by is None:
return []
expressions = []
group_by_refs = set()
if self.query.group_by is not True:
# If the group by is set to a list (by .values() call most likely),
# then we need to add everything in it to the GROUP BY clause.
# Backwards compatibility hack for setting query.group_by. Remove
# when we have public API way of forcing the GROUP BY clause.
# Converts string references to expressions.
for expr in self.query.group_by:
if not hasattr(expr, "as_sql"):
expr = self.query.resolve_ref(expr)
if isinstance(expr, Ref):
if expr.refs not in group_by_refs:
group_by_refs.add(expr.refs)
expressions.append(expr.source)
else:
expressions.append(expr)
# Note that even if the group_by is set, it is only the minimal
# set to group by. So, we need to add cols in select, order_by, and
# having into the select in any case.
selected_expr_indices = {}
for index, (expr, _, alias) in enumerate(select, start=1):
if alias:
selected_expr_indices[expr] = index
# Skip members of the select clause that are already explicitly
# grouped against.
if alias in group_by_refs:
continue
expressions.extend(expr.get_group_by_cols())
if not self._meta_ordering:
for expr, (sql, params, is_ref) in order_by:
# Skip references to the SELECT clause, as all expressions in
# the SELECT clause are already part of the GROUP BY.
if not is_ref:
expressions.extend(expr.get_group_by_cols())
having_group_by = self.having.get_group_by_cols() if self.having else ()
for expr in having_group_by:
expressions.append(expr)
result = []
seen = set()
expressions = self.collapse_group_by(expressions, having_group_by)
allows_group_by_select_index = (
self.connection.features.allows_group_by_select_index
)
for expr in expressions:
try:
sql, params = self.compile(expr)
except (EmptyResultSet, FullResultSet):
continue
if (
allows_group_by_select_index
and (select_index := selected_expr_indices.get(expr)) is not None
):
sql, params = str(select_index), ()
else:
sql, params = expr.select_format(self, sql, params)
params_hash = make_hashable(params)
if (sql, params_hash) not in seen:
result.append((sql, params))
seen.add((sql, params_hash))
return result
def collapse_group_by(self, expressions, having):
# If the database supports group by functional dependence reduction,
# then the expressions can be reduced to the set of selected table
# primary keys as all other columns are functionally dependent on them.
if self.connection.features.allows_group_by_selected_pks:
# Filter out all expressions associated with a table's primary key
# present in the grouped columns. This is done by identifying all
# tables that have their primary key included in the grouped
# columns and removing non-primary key columns referring to them.
# Unmanaged models are excluded because they could be representing
# database views on which the optimization might not be allowed.
pks = {
expr
for expr in expressions
if (
hasattr(expr, "target")
and expr.target.primary_key
and self.connection.features.allows_group_by_selected_pks_on_model(
expr.target.model
)
)
}
aliases = {expr.alias for expr in pks}
expressions = [
expr
for expr in expressions
if expr in pks
or expr in having
or getattr(expr, "alias", None) not in aliases
]
return expressions
def get_select(self, with_col_aliases=False):
"""
Return three values:
- a list of 3-tuples of (expression, (sql, params), alias)
- a klass_info structure,
- a dictionary of annotations
The (sql, params) is what the expression will produce, and alias is the
"AS alias" for the column (possibly None).
The klass_info structure contains the following information:
- The base model of the query.
- Which columns for that model are present in the query (by
position of the select clause).
- related_klass_infos: [f, klass_info] to descent into
The annotations is a dictionary of {'attname': column position} values.
"""
select = []
klass_info = None
annotations = {}
select_idx = 0
for alias, (sql, params) in self.query.extra_select.items():
annotations[alias] = select_idx
select.append((RawSQL(sql, params), alias))
select_idx += 1
assert not (self.query.select and self.query.default_cols)
select_mask = self.query.get_select_mask()
if self.query.default_cols:
cols = self.get_default_columns(select_mask)
else:
# self.query.select is a special case. These columns never go to
# any model.
cols = self.query.select
if cols:
select_list = []
for col in cols:
select_list.append(select_idx)
select.append((col, None))
select_idx += 1
klass_info = {
"model": self.query.model,
"select_fields": select_list,
}
for alias, annotation in self.query.annotation_select.items():
annotations[alias] = select_idx
select.append((annotation, alias))
select_idx += 1
if self.query.select_related:
related_klass_infos = self.get_related_selections(select, select_mask)
klass_info["related_klass_infos"] = related_klass_infos
def get_select_from_parent(klass_info):
for ki in klass_info["related_klass_infos"]:
if ki["from_parent"]:
ki["select_fields"] = (
klass_info["select_fields"] + ki["select_fields"]
)
get_select_from_parent(ki)
get_select_from_parent(klass_info)
ret = []
col_idx = 1
for col, alias in select:
try:
sql, params = self.compile(col)
except EmptyResultSet:
empty_result_set_value = getattr(
col, "empty_result_set_value", NotImplemented
)
if empty_result_set_value is NotImplemented:
# Select a predicate that's always False.
sql, params = "0", ()
else:
sql, params = self.compile(Value(empty_result_set_value))
except FullResultSet:
sql, params = self.compile(Value(True))
else:
sql, params = col.select_format(self, sql, params)
if alias is None and with_col_aliases:
alias = f"col{col_idx}"
col_idx += 1
ret.append((col, (sql, params), alias))
return ret, klass_info, annotations
def _order_by_pairs(self):
if self.query.extra_order_by:
ordering = self.query.extra_order_by
elif not self.query.default_ordering:
ordering = self.query.order_by
elif self.query.order_by:
ordering = self.query.order_by
elif (meta := self.query.get_meta()) and meta.ordering:
ordering = meta.ordering
self._meta_ordering = ordering
else:
ordering = []
if self.query.standard_ordering:
default_order, _ = ORDER_DIR["ASC"]
else:
default_order, _ = ORDER_DIR["DESC"]
selected_exprs = {}
# Avoid computing `selected_exprs` if there is no `ordering` as it's
# relatively expensive.
if ordering and (select := self.select):
for ordinal, (expr, _, alias) in enumerate(select, start=1):
pos_expr = PositionRef(ordinal, alias, expr)
if alias:
selected_exprs[alias] = pos_expr
selected_exprs[expr] = pos_expr
for field in ordering:
if hasattr(field, "resolve_expression"):
if isinstance(field, Value):
# output_field must be resolved for constants.
field = Cast(field, field.output_field)
if not isinstance(field, OrderBy):
field = field.asc()
if not self.query.standard_ordering:
field = field.copy()
field.reverse_ordering()
select_ref = selected_exprs.get(field.expression)
if select_ref or (
isinstance(field.expression, F)
and (select_ref := selected_exprs.get(field.expression.name))
):
# Emulation of NULLS (FIRST|LAST) cannot be combined with
# the usage of ordering by position.
if (
field.nulls_first is None and field.nulls_last is None
) or self.connection.features.supports_order_by_nulls_modifier:
field = field.copy()
field.expression = select_ref
# Alias collisions are not possible when dealing with
# combined queries so fallback to it if emulation of NULLS
# handling is required.
elif self.query.combinator:
field = field.copy()
field.expression = Ref(select_ref.refs, select_ref.source)
yield field, select_ref is not None
continue
if field == "?": # random
yield OrderBy(Random()), False
continue
col, order = get_order_dir(field, default_order)
descending = order == "DESC"
if select_ref := selected_exprs.get(col):
# Reference to expression in SELECT clause
yield (
OrderBy(
select_ref,
descending=descending,
),
True,
)
continue
if col in self.query.annotations:
# References to an expression which is masked out of the SELECT
# clause.
if self.query.combinator and self.select:
# Don't use the resolved annotation because other
# combinated queries might define it differently.
expr = F(col)
else:
expr = self.query.annotations[col]
if isinstance(expr, Value):
# output_field must be resolved for constants.
expr = Cast(expr, expr.output_field)
yield OrderBy(expr, descending=descending), False
continue
if "." in field:
# This came in through an extra(order_by=...) addition. Pass it
# on verbatim.
table, col = col.split(".", 1)
yield (
OrderBy(
RawSQL(
"%s.%s" % (self.quote_name_unless_alias(table), col), []
),
descending=descending,
),
False,
)
continue
if self.query.extra and col in self.query.extra:
if col in self.query.extra_select:
yield (
OrderBy(
Ref(col, RawSQL(*self.query.extra[col])),
descending=descending,
),
True,
)
else:
yield (
OrderBy(RawSQL(*self.query.extra[col]), descending=descending),
False,
)
else:
if self.query.combinator and self.select:
# Don't use the first model's field because other
# combinated queries might define it differently.
yield OrderBy(F(col), descending=descending), False
else:
# 'col' is of the form 'field' or 'field1__field2' or
# '-field1__field2__field', etc.
yield from self.find_ordering_name(
field,
self.query.get_meta(),
default_order=default_order,
)
def get_order_by(self):
"""
Return a list of 2-tuples of the form (expr, (sql, params, is_ref)) for
the ORDER BY clause.
The order_by clause can alter the select clause (for example it can add
aliases to clauses that do not yet have one, or it can add totally new
select clauses).
"""
result = []
seen = set()
for expr, is_ref in self._order_by_pairs():
resolved = expr.resolve_expression(self.query, allow_joins=True, reuse=None)
if not is_ref and self.query.combinator and self.select:
src = resolved.expression
expr_src = expr.expression
for sel_expr, _, col_alias in self.select:
if src == sel_expr:
# When values() is used the exact alias must be used to
# reference annotations.
if (
self.query.has_select_fields
and col_alias in self.query.annotation_select
and not (
isinstance(expr_src, F) and col_alias == expr_src.name
)
):
continue
resolved.set_source_expressions(
[Ref(col_alias if col_alias else src.target.column, src)]
)
break
else:
# Add column used in ORDER BY clause to the selected
# columns and to each combined query.
order_by_idx = len(self.query.select) + 1
col_alias = f"__orderbycol{order_by_idx}"
for q in self.query.combined_queries:
# If fields were explicitly selected through values()
# combined queries cannot be augmented.
if q.has_select_fields:
raise DatabaseError(
"ORDER BY term does not match any column in "
"the result set."
)
q.add_annotation(expr_src, col_alias)
self.query.add_select_col(resolved, col_alias)
resolved.set_source_expressions([Ref(col_alias, src)])
sql, params = self.compile(resolved)
# Don't add the same column twice, but the order direction is
# not taken into account so we strip it. When this entire method
# is refactored into expressions, then we can check each part as we
# generate it.
without_ordering = self.ordering_parts.search(sql)[1]
params_hash = make_hashable(params)
if (without_ordering, params_hash) in seen:
continue
seen.add((without_ordering, params_hash))
result.append((resolved, (sql, params, is_ref)))
return result
def get_extra_select(self, order_by, select):
extra_select = []
if self.query.distinct and not self.query.distinct_fields:
select_sql = [t[1] for t in select]
for expr, (sql, params, is_ref) in order_by:
without_ordering = self.ordering_parts.search(sql)[1]
if not is_ref and (without_ordering, params) not in select_sql:
extra_select.append((expr, (without_ordering, params), None))
return extra_select
def quote_name_unless_alias(self, name):
"""
A wrapper around connection.ops.quote_name that doesn't quote aliases
for table names. This avoids problems with some SQL dialects that treat
quoted strings specially (e.g. PostgreSQL).
"""
if name in self.quote_cache:
return self.quote_cache[name]
if (
(name in self.query.alias_map and name not in self.query.table_map)
or name in self.query.extra_select
or (
self.query.external_aliases.get(name)
and name not in self.query.table_map
)
):
self.quote_cache[name] = name
return name
r = self.connection.ops.quote_name(name)
self.quote_cache[name] = r
return r
def compile(self, node):
vendor_impl = getattr(node, "as_" + self.connection.vendor, None)
if vendor_impl:
sql, params = vendor_impl(self, self.connection)
else:
sql, params = node.as_sql(self, self.connection)
return sql, params
def get_combinator_sql(self, combinator, all):
features = self.connection.features
compilers = [
query.get_compiler(self.using, self.connection, self.elide_empty)
for query in self.query.combined_queries
]
if not features.supports_slicing_ordering_in_compound:
for compiler in compilers:
if compiler.query.is_sliced:
raise DatabaseError(
"LIMIT/OFFSET not allowed in subqueries of compound statements."
)
if compiler.get_order_by():
raise DatabaseError(
"ORDER BY not allowed in subqueries of compound statements."
)
elif self.query.is_sliced and combinator == "union":
for compiler in compilers:
# A sliced union cannot have its parts elided as some of them
# might be sliced as well and in the event where only a single
# part produces a non-empty resultset it might be impossible to
# generate valid SQL.
compiler.elide_empty = False
parts = ()
for compiler in compilers:
try:
# If the columns list is limited, then all combined queries
# must have the same columns list. Set the selects defined on
# the query on all combined queries, if not already set.
if not compiler.query.values_select and self.query.values_select:
compiler.query = compiler.query.clone()
compiler.query.set_values(
(
*self.query.extra_select,
*self.query.values_select,
*self.query.annotation_select,
)
)
part_sql, part_args = compiler.as_sql(with_col_aliases=True)
if compiler.query.combinator:
# Wrap in a subquery if wrapping in parentheses isn't
# supported.
if not features.supports_parentheses_in_compound:
part_sql = "SELECT * FROM ({})".format(part_sql)
# Add parentheses when combining with compound query if not
# already added for all compound queries.
elif (
self.query.subquery
or not features.supports_slicing_ordering_in_compound
):
part_sql = "({})".format(part_sql)
elif (
self.query.subquery
and features.supports_slicing_ordering_in_compound
):
part_sql = "({})".format(part_sql)
parts += ((part_sql, part_args),)
except EmptyResultSet:
# Omit the empty queryset with UNION and with DIFFERENCE if the
# first queryset is nonempty.
if combinator == "union" or (combinator == "difference" and parts):
continue
raise
if not parts:
raise EmptyResultSet
combinator_sql = self.connection.ops.set_operators[combinator]
if all and combinator == "union":
combinator_sql += " ALL"
braces = "{}"
if not self.query.subquery and features.supports_slicing_ordering_in_compound:
braces = "({})"
sql_parts, args_parts = zip(
*((braces.format(sql), args) for sql, args in parts)
)
result = [" {} ".format(combinator_sql).join(sql_parts)]
params = []
for part in args_parts:
params.extend(part)
return result, params
def get_qualify_sql(self):
where_parts = []
if self.where:
where_parts.append(self.where)
if self.having:
where_parts.append(self.having)
inner_query = self.query.clone()
inner_query.subquery = True
inner_query.where = inner_query.where.__class__(where_parts)
# Augment the inner query with any window function references that
# might have been masked via values() and alias(). If any masked
# aliases are added they'll be masked again to avoid fetching
# the data in the `if qual_aliases` branch below.
select = {
expr: alias for expr, _, alias in self.get_select(with_col_aliases=True)[0]
}
select_aliases = set(select.values())
qual_aliases = set()
replacements = {}
def collect_replacements(expressions):
while expressions:
expr = expressions.pop()
if expr in replacements:
continue
elif select_alias := select.get(expr):
replacements[expr] = select_alias
elif isinstance(expr, Lookup):
expressions.extend(expr.get_source_expressions())
elif isinstance(expr, Ref):
if expr.refs not in select_aliases:
expressions.extend(expr.get_source_expressions())
else:
num_qual_alias = len(qual_aliases)
select_alias = f"qual{num_qual_alias}"
qual_aliases.add(select_alias)
inner_query.add_annotation(expr, select_alias)
replacements[expr] = select_alias
collect_replacements(list(self.qualify.leaves()))
self.qualify = self.qualify.replace_expressions(
{expr: Ref(alias, expr) for expr, alias in replacements.items()}
)
order_by = []
for order_by_expr, *_ in self.get_order_by():
collect_replacements(order_by_expr.get_source_expressions())
order_by.append(
order_by_expr.replace_expressions(
{expr: Ref(alias, expr) for expr, alias in replacements.items()}
)
)
inner_query_compiler = inner_query.get_compiler(
self.using, connection=self.connection, elide_empty=self.elide_empty
)
inner_sql, inner_params = inner_query_compiler.as_sql(
# The limits must be applied to the outer query to avoid pruning
# results too eagerly.
with_limits=False,
# Force unique aliasing of selected columns to avoid collisions
# and make rhs predicates referencing easier.
with_col_aliases=True,
)
qualify_sql, qualify_params = self.compile(self.qualify)
result = [
"SELECT * FROM (",
inner_sql,
")",
self.connection.ops.quote_name("qualify"),
"WHERE",
qualify_sql,
]
if qual_aliases:
# If some select aliases were unmasked for filtering purposes they
# must be masked back.
cols = [self.connection.ops.quote_name(alias) for alias in select.values()]
result = [
"SELECT",
", ".join(cols),
"FROM (",
*result,
")",
self.connection.ops.quote_name("qualify_mask"),
]
params = list(inner_params) + qualify_params
# As the SQL spec is unclear on whether or not derived tables
# ordering must propagate it has to be explicitly repeated on the
# outer-most query to ensure it's preserved.
if order_by:
ordering_sqls = []
for ordering in order_by:
ordering_sql, ordering_params = self.compile(ordering)
ordering_sqls.append(ordering_sql)
params.extend(ordering_params)
result.extend(["ORDER BY", ", ".join(ordering_sqls)])
return result, params
def as_sql(self, with_limits=True, with_col_aliases=False):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
If 'with_limits' is False, any limit/offset information is not included
in the query.
"""
refcounts_before = self.query.alias_refcount.copy()
try:
combinator = self.query.combinator
extra_select, order_by, group_by = self.pre_sql_setup(
with_col_aliases=with_col_aliases or bool(combinator),
)
for_update_part = None
# Is a LIMIT/OFFSET clause needed?
with_limit_offset = with_limits and self.query.is_sliced
combinator = self.query.combinator
features = self.connection.features
if combinator:
if not getattr(features, "supports_select_{}".format(combinator)):
raise NotSupportedError(
"{} is not supported on this database backend.".format(
combinator
)
)
result, params = self.get_combinator_sql(
combinator, self.query.combinator_all
)
elif self.qualify:
result, params = self.get_qualify_sql()
order_by = None
else:
distinct_fields, distinct_params = self.get_distinct()
# This must come after 'select', 'ordering', and 'distinct'
# (see docstring of get_from_clause() for details).
from_, f_params = self.get_from_clause()
try:
where, w_params = (
self.compile(self.where) if self.where is not None else ("", [])
)
except EmptyResultSet:
if self.elide_empty:
raise
# Use a predicate that's always False.
where, w_params = "0 = 1", []
except FullResultSet:
where, w_params = "", []
try:
having, h_params = (
self.compile(self.having)
if self.having is not None
else ("", [])
)
except FullResultSet:
having, h_params = "", []
result = ["SELECT"]
params = []
if self.query.distinct:
distinct_result, distinct_params = self.connection.ops.distinct_sql(
distinct_fields,
distinct_params,
)
result += distinct_result
params += distinct_params
out_cols = []
for _, (s_sql, s_params), alias in self.select + extra_select:
if alias:
s_sql = "%s AS %s" % (
s_sql,
self.connection.ops.quote_name(alias),
)
params.extend(s_params)
out_cols.append(s_sql)
result += [", ".join(out_cols)]
if from_:
result += ["FROM", *from_]
elif self.connection.features.bare_select_suffix:
result += [self.connection.features.bare_select_suffix]
params.extend(f_params)
if self.query.select_for_update and features.has_select_for_update:
if (
self.connection.get_autocommit()
# Don't raise an exception when database doesn't
# support transactions, as it's a noop.
and features.supports_transactions
):
raise TransactionManagementError(
"select_for_update cannot be used outside of a transaction."
)
if (
with_limit_offset
and not features.supports_select_for_update_with_limit
):
raise NotSupportedError(
"LIMIT/OFFSET is not supported with "
"select_for_update on this database backend."
)
nowait = self.query.select_for_update_nowait
skip_locked = self.query.select_for_update_skip_locked
of = self.query.select_for_update_of
no_key = self.query.select_for_no_key_update
# If it's a NOWAIT/SKIP LOCKED/OF/NO KEY query but the
# backend doesn't support it, raise NotSupportedError to
# prevent a possible deadlock.
if nowait and not features.has_select_for_update_nowait:
raise NotSupportedError(
"NOWAIT is not supported on this database backend."
)
elif skip_locked and not features.has_select_for_update_skip_locked:
raise NotSupportedError(
"SKIP LOCKED is not supported on this database backend."
)
elif of and not features.has_select_for_update_of:
raise NotSupportedError(
"FOR UPDATE OF is not supported on this database backend."
)
elif no_key and not features.has_select_for_no_key_update:
raise NotSupportedError(
"FOR NO KEY UPDATE is not supported on this "
"database backend."
)
for_update_part = self.connection.ops.for_update_sql(
nowait=nowait,
skip_locked=skip_locked,
of=self.get_select_for_update_of_arguments(),
no_key=no_key,
)
if for_update_part and features.for_update_after_from:
result.append(for_update_part)
if where:
result.append("WHERE %s" % where)
params.extend(w_params)
grouping = []
for g_sql, g_params in group_by:
grouping.append(g_sql)
params.extend(g_params)
if grouping:
if distinct_fields:
raise NotImplementedError(
"annotate() + distinct(fields) is not implemented."
)
order_by = order_by or self.connection.ops.force_no_ordering()
result.append("GROUP BY %s" % ", ".join(grouping))
if self._meta_ordering:
order_by = None
if having:
result.append("HAVING %s" % having)
params.extend(h_params)
if self.query.explain_info:
result.insert(
0,
self.connection.ops.explain_query_prefix(
self.query.explain_info.format,
**self.query.explain_info.options,
),
)
if order_by:
ordering = []
for _, (o_sql, o_params, _) in order_by:
ordering.append(o_sql)
params.extend(o_params)
order_by_sql = "ORDER BY %s" % ", ".join(ordering)
if combinator and features.requires_compound_order_by_subquery:
result = ["SELECT * FROM (", *result, ")", order_by_sql]
else:
result.append(order_by_sql)
if with_limit_offset:
result.append(
self.connection.ops.limit_offset_sql(
self.query.low_mark, self.query.high_mark
)
)
if for_update_part and not features.for_update_after_from:
result.append(for_update_part)
if self.query.subquery and extra_select:
# If the query is used as a subquery, the extra selects would
# result in more columns than the left-hand side expression is
# expecting. This can happen when a subquery uses a combination
# of order_by() and distinct(), forcing the ordering expressions
# to be selected as well. Wrap the query in another subquery
# to exclude extraneous selects.
sub_selects = []
sub_params = []
for index, (select, _, alias) in enumerate(self.select, start=1):
if alias:
sub_selects.append(
"%s.%s"
% (
self.connection.ops.quote_name("subquery"),
self.connection.ops.quote_name(alias),
)
)
else:
select_clone = select.relabeled_clone(
{select.alias: "subquery"}
)
subselect, subparams = select_clone.as_sql(
self, self.connection
)
sub_selects.append(subselect)
sub_params.extend(subparams)
return "SELECT %s FROM (%s) subquery" % (
", ".join(sub_selects),
" ".join(result),
), tuple(sub_params + params)
return " ".join(result), tuple(params)
finally:
# Finally do cleanup - get rid of the joins we created above.
self.query.reset_refcounts(refcounts_before)
def get_default_columns(
self, select_mask, start_alias=None, opts=None, from_parent=None
):
"""
Compute the default columns for selecting every field in the base
model. Will sometimes be called to pull in related models (e.g. via
select_related), in which case "opts" and "start_alias" will be given
to provide a starting point for the traversal.
Return a list of strings, quoted appropriately for use in SQL
directly, as well as a set of aliases used in the select statement (if
'as_pairs' is True, return a list of (alias, col_name) pairs instead
of strings as the first component and None as the second component).
"""
result = []
if opts is None:
if (opts := self.query.get_meta()) is None:
return result
start_alias = start_alias or self.query.get_initial_alias()
# The 'seen_models' is used to optimize checking the needed parent
# alias for a given field. This also includes None -> start_alias to
# be used by local fields.
seen_models = {None: start_alias}
for field in opts.concrete_fields:
model = field.model._meta.concrete_model
# A proxy model will have a different model and concrete_model. We
# will assign None if the field belongs to this model.
if model == opts.model:
model = None
if (
from_parent
and model is not None
and issubclass(
from_parent._meta.concrete_model, model._meta.concrete_model
)
):
# Avoid loading data for already loaded parents.
# We end up here in the case select_related() resolution
# proceeds from parent model to child model. In that case the
# parent model data is already present in the SELECT clause,
# and we want to avoid reloading the same data again.
continue
if select_mask and field not in select_mask:
continue
alias = self.query.join_parent_model(opts, model, start_alias, seen_models)
column = field.get_col(alias)
result.append(column)
return result
def get_distinct(self):
"""
Return a quoted list of fields to use in DISTINCT ON part of the query.
This method can alter the tables in the query, and thus it must be
called before get_from_clause().
"""
result = []
params = []
opts = self.query.get_meta()
for name in self.query.distinct_fields:
parts = name.split(LOOKUP_SEP)
_, targets, alias, joins, path, _, transform_function = self._setup_joins(
parts, opts, None
)
targets, alias, _ = self.query.trim_joins(targets, joins, path)
for target in targets:
if name in self.query.annotation_select:
result.append(self.connection.ops.quote_name(name))
else:
r, p = self.compile(transform_function(target, alias))
result.append(r)
params.append(p)
return result, params
def find_ordering_name(
self, name, opts, alias=None, default_order="ASC", already_seen=None
):
"""
Return the table alias (the name might be ambiguous, the alias will
not be) and column name for ordering by the given 'name' parameter.
The 'name' is of the form 'field1__field2__...__fieldN'.
"""
name, order = get_order_dir(name, default_order)
descending = order == "DESC"
pieces = name.split(LOOKUP_SEP)
(
field,
targets,
alias,
joins,
path,
opts,
transform_function,
) = self._setup_joins(pieces, opts, alias)
# If we get to this point and the field is a relation to another model,
# append the default ordering for that model unless it is the pk
# shortcut or the attribute name of the field that is specified or
# there are transforms to process.
if (
field.is_relation
and opts.ordering
and getattr(field, "attname", None) != pieces[-1]
and name != "pk"
and not getattr(transform_function, "has_transforms", False)
):
# Firstly, avoid infinite loops.
already_seen = already_seen or set()
join_tuple = tuple(
getattr(self.query.alias_map[j], "join_cols", None) for j in joins
)
if join_tuple in already_seen:
raise FieldError("Infinite loop caused by ordering.")
already_seen.add(join_tuple)
results = []
for item in opts.ordering:
if hasattr(item, "resolve_expression") and not isinstance(
item, OrderBy
):
item = item.desc() if descending else item.asc()
if isinstance(item, OrderBy):
results.append(
(item.prefix_references(f"{name}{LOOKUP_SEP}"), False)
)
continue
results.extend(
(expr.prefix_references(f"{name}{LOOKUP_SEP}"), is_ref)
for expr, is_ref in self.find_ordering_name(
item, opts, alias, order, already_seen
)
)
return results
targets, alias, _ = self.query.trim_joins(targets, joins, path)
return [
(OrderBy(transform_function(t, alias), descending=descending), False)
for t in targets
]
def _setup_joins(self, pieces, opts, alias):
"""
Helper method for get_order_by() and get_distinct().
get_ordering() and get_distinct() must produce same target columns on
same input, as the prefixes of get_ordering() and get_distinct() must
match. Executing SQL where this is not true is an error.
"""
alias = alias or self.query.get_initial_alias()
field, targets, opts, joins, path, transform_function = self.query.setup_joins(
pieces, opts, alias
)
alias = joins[-1]
return field, targets, alias, joins, path, opts, transform_function
def get_from_clause(self):
"""
Return a list of strings that are joined together to go after the
"FROM" part of the query, as well as a list any extra parameters that
need to be included. Subclasses, can override this to create a
from-clause via a "select".
This should only be called after any SQL construction methods that
might change the tables that are needed. This means the select columns,
ordering, and distinct must be done first.
"""
result = []
params = []
for alias in tuple(self.query.alias_map):
if not self.query.alias_refcount[alias]:
continue
try:
from_clause = self.query.alias_map[alias]
except KeyError:
# Extra tables can end up in self.tables, but not in the
# alias_map if they aren't in a join. That's OK. We skip them.
continue
clause_sql, clause_params = self.compile(from_clause)
result.append(clause_sql)
params.extend(clause_params)
for t in self.query.extra_tables:
alias, _ = self.query.table_alias(t)
# Only add the alias if it's not already present (the table_alias()
# call increments the refcount, so an alias refcount of one means
# this is the only reference).
if (
alias not in self.query.alias_map
or self.query.alias_refcount[alias] == 1
):
result.append(", %s" % self.quote_name_unless_alias(alias))
return result, params
def get_related_selections(
self,
select,
select_mask,
opts=None,
root_alias=None,
cur_depth=1,
requested=None,
restricted=None,
):
"""
Fill in the information needed for a select_related query. The current
depth is measured as the number of connections away from the root model
(for example, cur_depth=1 means we are looking at models with direct
connections to the root model).
"""
def _get_field_choices():
direct_choices = (f.name for f in opts.fields if f.is_relation)
reverse_choices = (
f.field.related_query_name()
for f in opts.related_objects
if f.field.unique
)
return chain(
direct_choices, reverse_choices, self.query._filtered_relations
)
related_klass_infos = []
if not restricted and cur_depth > self.query.max_depth:
# We've recursed far enough; bail out.
return related_klass_infos
if not opts:
opts = self.query.get_meta()
root_alias = self.query.get_initial_alias()
# Setup for the case when only particular related fields should be
# included in the related selection.
fields_found = set()
if requested is None:
restricted = isinstance(self.query.select_related, dict)
if restricted:
requested = self.query.select_related
def get_related_klass_infos(klass_info, related_klass_infos):
klass_info["related_klass_infos"] = related_klass_infos
for f in opts.fields:
fields_found.add(f.name)
if restricted:
next = requested.get(f.name, {})
if not f.is_relation:
# If a non-related field is used like a relation,
# or if a single non-relational field is given.
if next or f.name in requested:
raise FieldError(
"Non-relational field given in select_related: '%s'. "
"Choices are: %s"
% (
f.name,
", ".join(_get_field_choices()) or "(none)",
)
)
else:
next = False
if not select_related_descend(f, restricted, requested, select_mask):
continue
related_select_mask = select_mask.get(f) or {}
klass_info = {
"model": f.remote_field.model,
"field": f,
"reverse": False,
"local_setter": f.set_cached_value,
"remote_setter": f.remote_field.set_cached_value
if f.unique
else lambda x, y: None,
"from_parent": False,
}
related_klass_infos.append(klass_info)
select_fields = []
_, _, _, joins, _, _ = self.query.setup_joins([f.name], opts, root_alias)
alias = joins[-1]
columns = self.get_default_columns(
related_select_mask, start_alias=alias, opts=f.remote_field.model._meta
)
for col in columns:
select_fields.append(len(select))
select.append((col, None))
klass_info["select_fields"] = select_fields
next_klass_infos = self.get_related_selections(
select,
related_select_mask,
f.remote_field.model._meta,
alias,
cur_depth + 1,
next,
restricted,
)
get_related_klass_infos(klass_info, next_klass_infos)
if restricted:
related_fields = [
(o.field, o.related_model)
for o in opts.related_objects
if o.field.unique and not o.many_to_many
]
for related_field, model in related_fields:
related_select_mask = select_mask.get(related_field) or {}
if not select_related_descend(
related_field,
restricted,
requested,
related_select_mask,
reverse=True,
):
continue
related_field_name = related_field.related_query_name()
fields_found.add(related_field_name)
join_info = self.query.setup_joins(
[related_field_name], opts, root_alias
)
alias = join_info.joins[-1]
from_parent = issubclass(model, opts.model) and model is not opts.model
klass_info = {
"model": model,
"field": related_field,
"reverse": True,
"local_setter": related_field.remote_field.set_cached_value,
"remote_setter": related_field.set_cached_value,
"from_parent": from_parent,
}
related_klass_infos.append(klass_info)
select_fields = []
columns = self.get_default_columns(
related_select_mask,
start_alias=alias,
opts=model._meta,
from_parent=opts.model,
)
for col in columns:
select_fields.append(len(select))
select.append((col, None))
klass_info["select_fields"] = select_fields
next = requested.get(related_field.related_query_name(), {})
next_klass_infos = self.get_related_selections(
select,
related_select_mask,
model._meta,
alias,
cur_depth + 1,
next,
restricted,
)
get_related_klass_infos(klass_info, next_klass_infos)
def local_setter(final_field, obj, from_obj):
# Set a reverse fk object when relation is non-empty.
if from_obj:
final_field.remote_field.set_cached_value(from_obj, obj)
def local_setter_noop(obj, from_obj):
pass
def remote_setter(name, obj, from_obj):
setattr(from_obj, name, obj)
for name in list(requested):
# Filtered relations work only on the topmost level.
if cur_depth > 1:
break
if name in self.query._filtered_relations:
fields_found.add(name)
final_field, _, join_opts, joins, _, _ = self.query.setup_joins(
[name], opts, root_alias
)
model = join_opts.model
alias = joins[-1]
from_parent = (
issubclass(model, opts.model) and model is not opts.model
)
klass_info = {
"model": model,
"field": final_field,
"reverse": True,
"local_setter": (
partial(local_setter, final_field)
if len(joins) <= 2
else local_setter_noop
),
"remote_setter": partial(remote_setter, name),
"from_parent": from_parent,
}
related_klass_infos.append(klass_info)
select_fields = []
field_select_mask = select_mask.get((name, final_field)) or {}
columns = self.get_default_columns(
field_select_mask,
start_alias=alias,
opts=model._meta,
from_parent=opts.model,
)
for col in columns:
select_fields.append(len(select))
select.append((col, None))
klass_info["select_fields"] = select_fields
next_requested = requested.get(name, {})
next_klass_infos = self.get_related_selections(
select,
field_select_mask,
opts=model._meta,
root_alias=alias,
cur_depth=cur_depth + 1,
requested=next_requested,
restricted=restricted,
)
get_related_klass_infos(klass_info, next_klass_infos)
fields_not_found = set(requested).difference(fields_found)
if fields_not_found:
invalid_fields = ("'%s'" % s for s in fields_not_found)
raise FieldError(
"Invalid field name(s) given in select_related: %s. "
"Choices are: %s"
% (
", ".join(invalid_fields),
", ".join(_get_field_choices()) or "(none)",
)
)
return related_klass_infos
def get_select_for_update_of_arguments(self):
"""
Return a quoted list of arguments for the SELECT FOR UPDATE OF part of
the query.
"""
def _get_parent_klass_info(klass_info):
concrete_model = klass_info["model"]._meta.concrete_model
for parent_model, parent_link in concrete_model._meta.parents.items():
parent_list = parent_model._meta.get_parent_list()
yield {
"model": parent_model,
"field": parent_link,
"reverse": False,
"select_fields": [
select_index
for select_index in klass_info["select_fields"]
# Selected columns from a model or its parents.
if (
self.select[select_index][0].target.model == parent_model
or self.select[select_index][0].target.model in parent_list
)
],
}
def _get_first_selected_col_from_model(klass_info):
"""
Find the first selected column from a model. If it doesn't exist,
don't lock a model.
select_fields is filled recursively, so it also contains fields
from the parent models.
"""
concrete_model = klass_info["model"]._meta.concrete_model
for select_index in klass_info["select_fields"]:
if self.select[select_index][0].target.model == concrete_model:
return self.select[select_index][0]
def _get_field_choices():
"""Yield all allowed field paths in breadth-first search order."""
queue = collections.deque([(None, self.klass_info)])
while queue:
parent_path, klass_info = queue.popleft()
if parent_path is None:
path = []
yield "self"
else:
field = klass_info["field"]
if klass_info["reverse"]:
field = field.remote_field
path = parent_path + [field.name]
yield LOOKUP_SEP.join(path)
queue.extend(
(path, klass_info)
for klass_info in _get_parent_klass_info(klass_info)
)
queue.extend(
(path, klass_info)
for klass_info in klass_info.get("related_klass_infos", [])
)
if not self.klass_info:
return []
result = []
invalid_names = []
for name in self.query.select_for_update_of:
klass_info = self.klass_info
if name == "self":
col = _get_first_selected_col_from_model(klass_info)
else:
for part in name.split(LOOKUP_SEP):
klass_infos = (
*klass_info.get("related_klass_infos", []),
*_get_parent_klass_info(klass_info),
)
for related_klass_info in klass_infos:
field = related_klass_info["field"]
if related_klass_info["reverse"]:
field = field.remote_field
if field.name == part:
klass_info = related_klass_info
break
else:
klass_info = None
break
if klass_info is None:
invalid_names.append(name)
continue
col = _get_first_selected_col_from_model(klass_info)
if col is not None:
if self.connection.features.select_for_update_of_column:
result.append(self.compile(col)[0])
else:
result.append(self.quote_name_unless_alias(col.alias))
if invalid_names:
raise FieldError(
"Invalid field name(s) given in select_for_update(of=(...)): %s. "
"Only relational fields followed in the query are allowed. "
"Choices are: %s."
% (
", ".join(invalid_names),
", ".join(_get_field_choices()),
)
)
return result
def get_converters(self, expressions):
converters = {}
for i, expression in enumerate(expressions):
if expression:
backend_converters = self.connection.ops.get_db_converters(expression)
field_converters = expression.get_db_converters(self.connection)
if backend_converters or field_converters:
converters[i] = (backend_converters + field_converters, expression)
return converters
def apply_converters(self, rows, converters):
connection = self.connection
converters = list(converters.items())
for row in map(list, rows):
for pos, (convs, expression) in converters:
value = row[pos]
for converter in convs:
value = converter(value, expression, connection)
row[pos] = value
yield row
def results_iter(
self,
results=None,
tuple_expected=False,
chunked_fetch=False,
chunk_size=GET_ITERATOR_CHUNK_SIZE,
):
"""Return an iterator over the results from executing this query."""
if results is None:
results = self.execute_sql(
MULTI, chunked_fetch=chunked_fetch, chunk_size=chunk_size
)
fields = [s[0] for s in self.select[0 : self.col_count]]
converters = self.get_converters(fields)
rows = chain.from_iterable(results)
if converters:
rows = self.apply_converters(rows, converters)
if tuple_expected:
rows = map(tuple, rows)
return rows
def has_results(self):
"""
Backends (e.g. NoSQL) can override this in order to use optimized
versions of "query has any results."
"""
return bool(self.execute_sql(SINGLE))
def execute_sql(
self, result_type=MULTI, chunked_fetch=False, chunk_size=GET_ITERATOR_CHUNK_SIZE
):
"""
Run the query against the database and return the result(s). The
return value is a single data item if result_type is SINGLE, or an
iterator over the results if the result_type is MULTI.
result_type is either MULTI (use fetchmany() to retrieve all rows),
SINGLE (only retrieve a single row), or None. In this last case, the
cursor is returned if any query is executed, since it's used by
subclasses such as InsertQuery). It's possible, however, that no query
is needed, as the filters describe an empty set. In that case, None is
returned, to avoid any unnecessary database interaction.
"""
result_type = result_type or NO_RESULTS
try:
sql, params = self.as_sql()
if not sql:
raise EmptyResultSet
except EmptyResultSet:
if result_type == MULTI:
return iter([])
else:
return
if chunked_fetch:
cursor = self.connection.chunked_cursor()
else:
cursor = self.connection.cursor()
try:
cursor.execute(sql, params)
except Exception:
# Might fail for server-side cursors (e.g. connection closed)
cursor.close()
raise
if result_type == CURSOR:
# Give the caller the cursor to process and close.
return cursor
if result_type == SINGLE:
try:
val = cursor.fetchone()
if val:
return val[0 : self.col_count]
return val
finally:
# done with the cursor
cursor.close()
if result_type == NO_RESULTS:
cursor.close()
return
result = cursor_iter(
cursor,
self.connection.features.empty_fetchmany_value,
self.col_count if self.has_extra_select else None,
chunk_size,
)
if not chunked_fetch or not self.connection.features.can_use_chunked_reads:
# If we are using non-chunked reads, we return the same data
# structure as normally, but ensure it is all read into memory
# before going any further. Use chunked_fetch if requested,
# unless the database doesn't support it.
return list(result)
return result
def as_subquery_condition(self, alias, columns, compiler):
qn = compiler.quote_name_unless_alias
qn2 = self.connection.ops.quote_name
for index, select_col in enumerate(self.query.select):
lhs_sql, lhs_params = self.compile(select_col)
rhs = "%s.%s" % (qn(alias), qn2(columns[index]))
self.query.where.add(RawSQL("%s = %s" % (lhs_sql, rhs), lhs_params), AND)
sql, params = self.as_sql()
return "EXISTS (%s)" % sql, params
def explain_query(self):
result = list(self.execute_sql())
# Some backends return 1 item tuples with strings, and others return
# tuples with integers and strings. Flatten them out into strings.
format_ = self.query.explain_info.format
output_formatter = json.dumps if format_ and format_.lower() == "json" else str
for row in result[0]:
if not isinstance(row, str):
yield " ".join(output_formatter(c) for c in row)
else:
yield row
class SQLInsertCompiler(SQLCompiler):
returning_fields = None
returning_params = ()
def field_as_sql(self, field, val):
"""
Take a field and a value intended to be saved on that field, and
return placeholder SQL and accompanying params. Check for raw values,
expressions, and fields with get_placeholder() defined in that order.
When field is None, consider the value raw and use it as the
placeholder, with no corresponding parameters returned.
"""
if field is None:
# A field value of None means the value is raw.
sql, params = val, []
elif hasattr(val, "as_sql"):
# This is an expression, let's compile it.
sql, params = self.compile(val)
elif hasattr(field, "get_placeholder"):
# Some fields (e.g. geo fields) need special munging before
# they can be inserted.
sql, params = field.get_placeholder(val, self, self.connection), [val]
else:
# Return the common case for the placeholder
sql, params = "%s", [val]
# The following hook is only used by Oracle Spatial, which sometimes
# needs to yield 'NULL' and [] as its placeholder and params instead
# of '%s' and [None]. The 'NULL' placeholder is produced earlier by
# OracleOperations.get_geom_placeholder(). The following line removes
# the corresponding None parameter. See ticket #10888.
params = self.connection.ops.modify_insert_params(sql, params)
return sql, params
def prepare_value(self, field, value):
"""
Prepare a value to be used in a query by resolving it if it is an
expression and otherwise calling the field's get_db_prep_save().
"""
if hasattr(value, "resolve_expression"):
value = value.resolve_expression(
self.query, allow_joins=False, for_save=True
)
# Don't allow values containing Col expressions. They refer to
# existing columns on a row, but in the case of insert the row
# doesn't exist yet.
if value.contains_column_references:
raise ValueError(
'Failed to insert expression "%s" on %s. F() expressions '
"can only be used to update, not to insert." % (value, field)
)
if value.contains_aggregate:
raise FieldError(
"Aggregate functions are not allowed in this query "
"(%s=%r)." % (field.name, value)
)
if value.contains_over_clause:
raise FieldError(
"Window expressions are not allowed in this query (%s=%r)."
% (field.name, value)
)
return field.get_db_prep_save(value, connection=self.connection)
def pre_save_val(self, field, obj):
"""
Get the given field's value off the given obj. pre_save() is used for
things like auto_now on DateTimeField. Skip it if this is a raw query.
"""
if self.query.raw:
return getattr(obj, field.attname)
return field.pre_save(obj, add=True)
def assemble_as_sql(self, fields, value_rows):
"""
Take a sequence of N fields and a sequence of M rows of values, and
generate placeholder SQL and parameters for each field and value.
Return a pair containing:
* a sequence of M rows of N SQL placeholder strings, and
* a sequence of M rows of corresponding parameter values.
Each placeholder string may contain any number of '%s' interpolation
strings, and each parameter row will contain exactly as many params
as the total number of '%s's in the corresponding placeholder row.
"""
if not value_rows:
return [], []
# list of (sql, [params]) tuples for each object to be saved
# Shape: [n_objs][n_fields][2]
rows_of_fields_as_sql = (
(self.field_as_sql(field, v) for field, v in zip(fields, row))
for row in value_rows
)
# tuple like ([sqls], [[params]s]) for each object to be saved
# Shape: [n_objs][2][n_fields]
sql_and_param_pair_rows = (zip(*row) for row in rows_of_fields_as_sql)
# Extract separate lists for placeholders and params.
# Each of these has shape [n_objs][n_fields]
placeholder_rows, param_rows = zip(*sql_and_param_pair_rows)
# Params for each field are still lists, and need to be flattened.
param_rows = [[p for ps in row for p in ps] for row in param_rows]
return placeholder_rows, param_rows
def as_sql(self):
# We don't need quote_name_unless_alias() here, since these are all
# going to be column names (so we can avoid the extra overhead).
qn = self.connection.ops.quote_name
opts = self.query.get_meta()
insert_statement = self.connection.ops.insert_statement(
on_conflict=self.query.on_conflict,
)
result = ["%s %s" % (insert_statement, qn(opts.db_table))]
fields = self.query.fields or [opts.pk]
result.append("(%s)" % ", ".join(qn(f.column) for f in fields))
if self.query.fields:
value_rows = [
[
self.prepare_value(field, self.pre_save_val(field, obj))
for field in fields
]
for obj in self.query.objs
]
else:
# An empty object.
value_rows = [
[self.connection.ops.pk_default_value()] for _ in self.query.objs
]
fields = [None]
# Currently the backends just accept values when generating bulk
# queries and generate their own placeholders. Doing that isn't
# necessary and it should be possible to use placeholders and
# expressions in bulk inserts too.
can_bulk = (
not self.returning_fields and self.connection.features.has_bulk_insert
)
placeholder_rows, param_rows = self.assemble_as_sql(fields, value_rows)
on_conflict_suffix_sql = self.connection.ops.on_conflict_suffix_sql(
fields,
self.query.on_conflict,
(f.column for f in self.query.update_fields),
(f.column for f in self.query.unique_fields),
)
if (
self.returning_fields
and self.connection.features.can_return_columns_from_insert
):
if self.connection.features.can_return_rows_from_bulk_insert:
result.append(
self.connection.ops.bulk_insert_sql(fields, placeholder_rows)
)
params = param_rows
else:
result.append("VALUES (%s)" % ", ".join(placeholder_rows[0]))
params = [param_rows[0]]
if on_conflict_suffix_sql:
result.append(on_conflict_suffix_sql)
# Skip empty r_sql to allow subclasses to customize behavior for
# 3rd party backends. Refs #19096.
r_sql, self.returning_params = self.connection.ops.return_insert_columns(
self.returning_fields
)
if r_sql:
result.append(r_sql)
params += [self.returning_params]
return [(" ".join(result), tuple(chain.from_iterable(params)))]
if can_bulk:
result.append(self.connection.ops.bulk_insert_sql(fields, placeholder_rows))
if on_conflict_suffix_sql:
result.append(on_conflict_suffix_sql)
return [(" ".join(result), tuple(p for ps in param_rows for p in ps))]
else:
if on_conflict_suffix_sql:
result.append(on_conflict_suffix_sql)
return [
(" ".join(result + ["VALUES (%s)" % ", ".join(p)]), vals)
for p, vals in zip(placeholder_rows, param_rows)
]
def execute_sql(self, returning_fields=None):
assert not (
returning_fields
and len(self.query.objs) != 1
and not self.connection.features.can_return_rows_from_bulk_insert
)
opts = self.query.get_meta()
self.returning_fields = returning_fields
with self.connection.cursor() as cursor:
for sql, params in self.as_sql():
cursor.execute(sql, params)
if not self.returning_fields:
return []
if (
self.connection.features.can_return_rows_from_bulk_insert
and len(self.query.objs) > 1
):
rows = self.connection.ops.fetch_returned_insert_rows(cursor)
elif self.connection.features.can_return_columns_from_insert:
assert len(self.query.objs) == 1
rows = [
self.connection.ops.fetch_returned_insert_columns(
cursor,
self.returning_params,
)
]
else:
rows = [
(
self.connection.ops.last_insert_id(
cursor,
opts.db_table,
opts.pk.column,
),
)
]
cols = [field.get_col(opts.db_table) for field in self.returning_fields]
converters = self.get_converters(cols)
if converters:
rows = list(self.apply_converters(rows, converters))
return rows
class SQLDeleteCompiler(SQLCompiler):
@cached_property
def single_alias(self):
# Ensure base table is in aliases.
self.query.get_initial_alias()
return sum(self.query.alias_refcount[t] > 0 for t in self.query.alias_map) == 1
@classmethod
def _expr_refs_base_model(cls, expr, base_model):
if isinstance(expr, Query):
return expr.model == base_model
if not hasattr(expr, "get_source_expressions"):
return False
return any(
cls._expr_refs_base_model(source_expr, base_model)
for source_expr in expr.get_source_expressions()
)
@cached_property
def contains_self_reference_subquery(self):
return any(
self._expr_refs_base_model(expr, self.query.model)
for expr in chain(
self.query.annotations.values(), self.query.where.children
)
)
def _as_sql(self, query):
delete = "DELETE FROM %s" % self.quote_name_unless_alias(query.base_table)
try:
where, params = self.compile(query.where)
except FullResultSet:
return delete, ()
return f"{delete} WHERE {where}", tuple(params)
def as_sql(self):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
"""
if self.single_alias and not self.contains_self_reference_subquery:
return self._as_sql(self.query)
innerq = self.query.clone()
innerq.__class__ = Query
innerq.clear_select_clause()
pk = self.query.model._meta.pk
innerq.select = [pk.get_col(self.query.get_initial_alias())]
outerq = Query(self.query.model)
if not self.connection.features.update_can_self_select:
# Force the materialization of the inner query to allow reference
# to the target table on MySQL.
sql, params = innerq.get_compiler(connection=self.connection).as_sql()
innerq = RawSQL("SELECT * FROM (%s) subquery" % sql, params)
outerq.add_filter("pk__in", innerq)
return self._as_sql(outerq)
class SQLUpdateCompiler(SQLCompiler):
def as_sql(self):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
"""
self.pre_sql_setup()
if not self.query.values:
return "", ()
qn = self.quote_name_unless_alias
values, update_params = [], []
for field, model, val in self.query.values:
if hasattr(val, "resolve_expression"):
val = val.resolve_expression(
self.query, allow_joins=False, for_save=True
)
if val.contains_aggregate:
raise FieldError(
"Aggregate functions are not allowed in this query "
"(%s=%r)." % (field.name, val)
)
if val.contains_over_clause:
raise FieldError(
"Window expressions are not allowed in this query "
"(%s=%r)." % (field.name, val)
)
elif hasattr(val, "prepare_database_save"):
if field.remote_field:
val = val.prepare_database_save(field)
else:
raise TypeError(
"Tried to update field %s with a model instance, %r. "
"Use a value compatible with %s."
% (field, val, field.__class__.__name__)
)
val = field.get_db_prep_save(val, connection=self.connection)
# Getting the placeholder for the field.
if hasattr(field, "get_placeholder"):
placeholder = field.get_placeholder(val, self, self.connection)
else:
placeholder = "%s"
name = field.column
if hasattr(val, "as_sql"):
sql, params = self.compile(val)
values.append("%s = %s" % (qn(name), placeholder % sql))
update_params.extend(params)
elif val is not None:
values.append("%s = %s" % (qn(name), placeholder))
update_params.append(val)
else:
values.append("%s = NULL" % qn(name))
table = self.query.base_table
result = [
"UPDATE %s SET" % qn(table),
", ".join(values),
]
try:
where, params = self.compile(self.query.where)
except FullResultSet:
params = []
else:
result.append("WHERE %s" % where)
return " ".join(result), tuple(update_params + params)
def execute_sql(self, result_type):
"""
Execute the specified update. Return the number of rows affected by
the primary update query. The "primary update query" is the first
non-empty query that is executed. Row counts for any subsequent,
related queries are not available.
"""
cursor = super().execute_sql(result_type)
try:
rows = cursor.rowcount if cursor else 0
is_empty = cursor is None
finally:
if cursor:
cursor.close()
for query in self.query.get_related_updates():
aux_rows = query.get_compiler(self.using).execute_sql(result_type)
if is_empty and aux_rows:
rows = aux_rows
is_empty = False
return rows
def pre_sql_setup(self):
"""
If the update depends on results from other tables, munge the "where"
conditions to match the format required for (portable) SQL updates.
If multiple updates are required, pull out the id values to update at
this point so that they don't change as a result of the progressive
updates.
"""
refcounts_before = self.query.alias_refcount.copy()
# Ensure base table is in the query
self.query.get_initial_alias()
count = self.query.count_active_tables()
if not self.query.related_updates and count == 1:
return
query = self.query.chain(klass=Query)
query.select_related = False
query.clear_ordering(force=True)
query.extra = {}
query.select = []
meta = query.get_meta()
fields = [meta.pk.name]
related_ids_index = []
for related in self.query.related_updates:
if all(
path.join_field.primary_key for path in meta.get_path_to_parent(related)
):
# If a primary key chain exists to the targeted related update,
# then the meta.pk value can be used for it.
related_ids_index.append((related, 0))
else:
# This branch will only be reached when updating a field of an
# ancestor that is not part of the primary key chain of a MTI
# tree.
related_ids_index.append((related, len(fields)))
fields.append(related._meta.pk.name)
query.add_fields(fields)
super().pre_sql_setup()
must_pre_select = (
count > 1 and not self.connection.features.update_can_self_select
)
# Now we adjust the current query: reset the where clause and get rid
# of all the tables we don't need (since they're in the sub-select).
self.query.clear_where()
if self.query.related_updates or must_pre_select:
# Either we're using the idents in multiple update queries (so
# don't want them to change), or the db backend doesn't support
# selecting from the updating table (e.g. MySQL).
idents = []
related_ids = collections.defaultdict(list)
for rows in query.get_compiler(self.using).execute_sql(MULTI):
idents.extend(r[0] for r in rows)
for parent, index in related_ids_index:
related_ids[parent].extend(r[index] for r in rows)
self.query.add_filter("pk__in", idents)
self.query.related_ids = related_ids
else:
# The fast path. Filters and updates in one query.
self.query.add_filter("pk__in", query)
self.query.reset_refcounts(refcounts_before)
class SQLAggregateCompiler(SQLCompiler):
def as_sql(self):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
"""
sql, params = [], []
for annotation in self.query.annotation_select.values():
ann_sql, ann_params = self.compile(annotation)
ann_sql, ann_params = annotation.select_format(self, ann_sql, ann_params)
sql.append(ann_sql)
params.extend(ann_params)
self.col_count = len(self.query.annotation_select)
sql = ", ".join(sql)
params = tuple(params)
inner_query_sql, inner_query_params = self.query.inner_query.get_compiler(
self.using,
elide_empty=self.elide_empty,
).as_sql(with_col_aliases=True)
sql = "SELECT %s FROM (%s) subquery" % (sql, inner_query_sql)
params += inner_query_params
return sql, params
def cursor_iter(cursor, sentinel, col_count, itersize):
"""
Yield blocks of rows from a cursor and ensure the cursor is closed when
done.
"""
try:
for rows in iter((lambda: cursor.fetchmany(itersize)), sentinel):
yield rows if col_count is None else [r[:col_count] for r in rows]
finally:
cursor.close()
|
castiel248/Convert
|
Lib/site-packages/django/db/models/sql/compiler.py
|
Python
|
mit
| 89,132 |
"""
Constants specific to the SQL storage portion of the ORM.
"""
# Size of each "chunk" for get_iterator calls.
# Larger values are slightly faster at the expense of more storage space.
GET_ITERATOR_CHUNK_SIZE = 100
# Namedtuples for sql.* internal use.
# How many results to expect from a cursor.execute call
MULTI = "multi"
SINGLE = "single"
CURSOR = "cursor"
NO_RESULTS = "no results"
ORDER_DIR = {
"ASC": ("ASC", "DESC"),
"DESC": ("DESC", "ASC"),
}
# SQL join types.
INNER = "INNER JOIN"
LOUTER = "LEFT OUTER JOIN"
|
castiel248/Convert
|
Lib/site-packages/django/db/models/sql/constants.py
|
Python
|
mit
| 533 |
"""
Useful auxiliary data structures for query construction. Not useful outside
the SQL domain.
"""
from django.core.exceptions import FullResultSet
from django.db.models.sql.constants import INNER, LOUTER
class MultiJoin(Exception):
"""
Used by join construction code to indicate the point at which a
multi-valued join was attempted (if the caller wants to treat that
exceptionally).
"""
def __init__(self, names_pos, path_with_names):
self.level = names_pos
# The path travelled, this includes the path to the multijoin.
self.names_with_path = path_with_names
class Empty:
pass
class Join:
"""
Used by sql.Query and sql.SQLCompiler to generate JOIN clauses into the
FROM entry. For example, the SQL generated could be
LEFT OUTER JOIN "sometable" T1
ON ("othertable"."sometable_id" = "sometable"."id")
This class is primarily used in Query.alias_map. All entries in alias_map
must be Join compatible by providing the following attributes and methods:
- table_name (string)
- table_alias (possible alias for the table, can be None)
- join_type (can be None for those entries that aren't joined from
anything)
- parent_alias (which table is this join's parent, can be None similarly
to join_type)
- as_sql()
- relabeled_clone()
"""
def __init__(
self,
table_name,
parent_alias,
table_alias,
join_type,
join_field,
nullable,
filtered_relation=None,
):
# Join table
self.table_name = table_name
self.parent_alias = parent_alias
# Note: table_alias is not necessarily known at instantiation time.
self.table_alias = table_alias
# LOUTER or INNER
self.join_type = join_type
# A list of 2-tuples to use in the ON clause of the JOIN.
# Each 2-tuple will create one join condition in the ON clause.
self.join_cols = join_field.get_joining_columns()
# Along which field (or ForeignObjectRel in the reverse join case)
self.join_field = join_field
# Is this join nullabled?
self.nullable = nullable
self.filtered_relation = filtered_relation
def as_sql(self, compiler, connection):
"""
Generate the full
LEFT OUTER JOIN sometable ON sometable.somecol = othertable.othercol, params
clause for this join.
"""
join_conditions = []
params = []
qn = compiler.quote_name_unless_alias
qn2 = connection.ops.quote_name
# Add a join condition for each pair of joining columns.
for lhs_col, rhs_col in self.join_cols:
join_conditions.append(
"%s.%s = %s.%s"
% (
qn(self.parent_alias),
qn2(lhs_col),
qn(self.table_alias),
qn2(rhs_col),
)
)
# Add a single condition inside parentheses for whatever
# get_extra_restriction() returns.
extra_cond = self.join_field.get_extra_restriction(
self.table_alias, self.parent_alias
)
if extra_cond:
extra_sql, extra_params = compiler.compile(extra_cond)
join_conditions.append("(%s)" % extra_sql)
params.extend(extra_params)
if self.filtered_relation:
try:
extra_sql, extra_params = compiler.compile(self.filtered_relation)
except FullResultSet:
pass
else:
join_conditions.append("(%s)" % extra_sql)
params.extend(extra_params)
if not join_conditions:
# This might be a rel on the other end of an actual declared field.
declared_field = getattr(self.join_field, "field", self.join_field)
raise ValueError(
"Join generated an empty ON clause. %s did not yield either "
"joining columns or extra restrictions." % declared_field.__class__
)
on_clause_sql = " AND ".join(join_conditions)
alias_str = (
"" if self.table_alias == self.table_name else (" %s" % self.table_alias)
)
sql = "%s %s%s ON (%s)" % (
self.join_type,
qn(self.table_name),
alias_str,
on_clause_sql,
)
return sql, params
def relabeled_clone(self, change_map):
new_parent_alias = change_map.get(self.parent_alias, self.parent_alias)
new_table_alias = change_map.get(self.table_alias, self.table_alias)
if self.filtered_relation is not None:
filtered_relation = self.filtered_relation.clone()
filtered_relation.path = [
change_map.get(p, p) for p in self.filtered_relation.path
]
else:
filtered_relation = None
return self.__class__(
self.table_name,
new_parent_alias,
new_table_alias,
self.join_type,
self.join_field,
self.nullable,
filtered_relation=filtered_relation,
)
@property
def identity(self):
return (
self.__class__,
self.table_name,
self.parent_alias,
self.join_field,
self.filtered_relation,
)
def __eq__(self, other):
if not isinstance(other, Join):
return NotImplemented
return self.identity == other.identity
def __hash__(self):
return hash(self.identity)
def equals(self, other):
# Ignore filtered_relation in equality check.
return self.identity[:-1] == other.identity[:-1]
def demote(self):
new = self.relabeled_clone({})
new.join_type = INNER
return new
def promote(self):
new = self.relabeled_clone({})
new.join_type = LOUTER
return new
class BaseTable:
"""
The BaseTable class is used for base table references in FROM clause. For
example, the SQL "foo" in
SELECT * FROM "foo" WHERE somecond
could be generated by this class.
"""
join_type = None
parent_alias = None
filtered_relation = None
def __init__(self, table_name, alias):
self.table_name = table_name
self.table_alias = alias
def as_sql(self, compiler, connection):
alias_str = (
"" if self.table_alias == self.table_name else (" %s" % self.table_alias)
)
base_sql = compiler.quote_name_unless_alias(self.table_name)
return base_sql + alias_str, []
def relabeled_clone(self, change_map):
return self.__class__(
self.table_name, change_map.get(self.table_alias, self.table_alias)
)
@property
def identity(self):
return self.__class__, self.table_name, self.table_alias
def __eq__(self, other):
if not isinstance(other, BaseTable):
return NotImplemented
return self.identity == other.identity
def __hash__(self):
return hash(self.identity)
def equals(self, other):
return self.identity == other.identity
|
castiel248/Convert
|
Lib/site-packages/django/db/models/sql/datastructures.py
|
Python
|
mit
| 7,297 |
"""
Create SQL statements for QuerySets.
The code in here encapsulates all of the SQL construction so that QuerySets
themselves do not have to (and could be backed by things other than SQL
databases). The abstraction barrier only works one way: this module has to know
all about the internals of models in order to get the information it needs.
"""
import copy
import difflib
import functools
import sys
from collections import Counter, namedtuple
from collections.abc import Iterator, Mapping
from itertools import chain, count, product
from string import ascii_uppercase
from django.core.exceptions import FieldDoesNotExist, FieldError
from django.db import DEFAULT_DB_ALIAS, NotSupportedError, connections
from django.db.models.aggregates import Count
from django.db.models.constants import LOOKUP_SEP
from django.db.models.expressions import (
BaseExpression,
Col,
Exists,
F,
OuterRef,
Ref,
ResolvedOuterRef,
Value,
)
from django.db.models.fields import Field
from django.db.models.fields.related_lookups import MultiColSource
from django.db.models.lookups import Lookup
from django.db.models.query_utils import (
Q,
check_rel_lookup_compatibility,
refs_expression,
)
from django.db.models.sql.constants import INNER, LOUTER, ORDER_DIR, SINGLE
from django.db.models.sql.datastructures import BaseTable, Empty, Join, MultiJoin
from django.db.models.sql.where import AND, OR, ExtraWhere, NothingNode, WhereNode
from django.utils.functional import cached_property
from django.utils.regex_helper import _lazy_re_compile
from django.utils.tree import Node
__all__ = ["Query", "RawQuery"]
# Quotation marks ('"`[]), whitespace characters, semicolons, or inline
# SQL comments are forbidden in column aliases.
FORBIDDEN_ALIAS_PATTERN = _lazy_re_compile(r"['`\"\]\[;\s]|--|/\*|\*/")
# Inspired from
# https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS
EXPLAIN_OPTIONS_PATTERN = _lazy_re_compile(r"[\w\-]+")
def get_field_names_from_opts(opts):
if opts is None:
return set()
return set(
chain.from_iterable(
(f.name, f.attname) if f.concrete else (f.name,) for f in opts.get_fields()
)
)
def get_children_from_q(q):
for child in q.children:
if isinstance(child, Node):
yield from get_children_from_q(child)
else:
yield child
JoinInfo = namedtuple(
"JoinInfo",
("final_field", "targets", "opts", "joins", "path", "transform_function"),
)
class RawQuery:
"""A single raw SQL query."""
def __init__(self, sql, using, params=()):
self.params = params
self.sql = sql
self.using = using
self.cursor = None
# Mirror some properties of a normal query so that
# the compiler can be used to process results.
self.low_mark, self.high_mark = 0, None # Used for offset/limit
self.extra_select = {}
self.annotation_select = {}
def chain(self, using):
return self.clone(using)
def clone(self, using):
return RawQuery(self.sql, using, params=self.params)
def get_columns(self):
if self.cursor is None:
self._execute_query()
converter = connections[self.using].introspection.identifier_converter
return [converter(column_meta[0]) for column_meta in self.cursor.description]
def __iter__(self):
# Always execute a new query for a new iterator.
# This could be optimized with a cache at the expense of RAM.
self._execute_query()
if not connections[self.using].features.can_use_chunked_reads:
# If the database can't use chunked reads we need to make sure we
# evaluate the entire query up front.
result = list(self.cursor)
else:
result = self.cursor
return iter(result)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
@property
def params_type(self):
if self.params is None:
return None
return dict if isinstance(self.params, Mapping) else tuple
def __str__(self):
if self.params_type is None:
return self.sql
return self.sql % self.params_type(self.params)
def _execute_query(self):
connection = connections[self.using]
# Adapt parameters to the database, as much as possible considering
# that the target type isn't known. See #17755.
params_type = self.params_type
adapter = connection.ops.adapt_unknown_value
if params_type is tuple:
params = tuple(adapter(val) for val in self.params)
elif params_type is dict:
params = {key: adapter(val) for key, val in self.params.items()}
elif params_type is None:
params = None
else:
raise RuntimeError("Unexpected params type: %s" % params_type)
self.cursor = connection.cursor()
self.cursor.execute(self.sql, params)
ExplainInfo = namedtuple("ExplainInfo", ("format", "options"))
class Query(BaseExpression):
"""A single SQL query."""
alias_prefix = "T"
empty_result_set_value = None
subq_aliases = frozenset([alias_prefix])
compiler = "SQLCompiler"
base_table_class = BaseTable
join_class = Join
default_cols = True
default_ordering = True
standard_ordering = True
filter_is_sticky = False
subquery = False
# SQL-related attributes.
# Select and related select clauses are expressions to use in the SELECT
# clause of the query. The select is used for cases where we want to set up
# the select clause to contain other than default fields (values(),
# subqueries...). Note that annotations go to annotations dictionary.
select = ()
# The group_by attribute can have one of the following forms:
# - None: no group by at all in the query
# - A tuple of expressions: group by (at least) those expressions.
# String refs are also allowed for now.
# - True: group by all select fields of the model
# See compiler.get_group_by() for details.
group_by = None
order_by = ()
low_mark = 0 # Used for offset/limit.
high_mark = None # Used for offset/limit.
distinct = False
distinct_fields = ()
select_for_update = False
select_for_update_nowait = False
select_for_update_skip_locked = False
select_for_update_of = ()
select_for_no_key_update = False
select_related = False
has_select_fields = False
# Arbitrary limit for select_related to prevents infinite recursion.
max_depth = 5
# Holds the selects defined by a call to values() or values_list()
# excluding annotation_select and extra_select.
values_select = ()
# SQL annotation-related attributes.
annotation_select_mask = None
_annotation_select_cache = None
# Set combination attributes.
combinator = None
combinator_all = False
combined_queries = ()
# These are for extensions. The contents are more or less appended verbatim
# to the appropriate clause.
extra_select_mask = None
_extra_select_cache = None
extra_tables = ()
extra_order_by = ()
# A tuple that is a set of model field names and either True, if these are
# the fields to defer, or False if these are the only fields to load.
deferred_loading = (frozenset(), True)
explain_info = None
def __init__(self, model, alias_cols=True):
self.model = model
self.alias_refcount = {}
# alias_map is the most important data structure regarding joins.
# It's used for recording which joins exist in the query and what
# types they are. The key is the alias of the joined table (possibly
# the table name) and the value is a Join-like object (see
# sql.datastructures.Join for more information).
self.alias_map = {}
# Whether to provide alias to columns during reference resolving.
self.alias_cols = alias_cols
# Sometimes the query contains references to aliases in outer queries (as
# a result of split_exclude). Correct alias quoting needs to know these
# aliases too.
# Map external tables to whether they are aliased.
self.external_aliases = {}
self.table_map = {} # Maps table names to list of aliases.
self.used_aliases = set()
self.where = WhereNode()
# Maps alias -> Annotation Expression.
self.annotations = {}
# These are for extensions. The contents are more or less appended
# verbatim to the appropriate clause.
self.extra = {} # Maps col_alias -> (col_sql, params).
self._filtered_relations = {}
@property
def output_field(self):
if len(self.select) == 1:
select = self.select[0]
return getattr(select, "target", None) or select.field
elif len(self.annotation_select) == 1:
return next(iter(self.annotation_select.values())).output_field
@cached_property
def base_table(self):
for alias in self.alias_map:
return alias
def __str__(self):
"""
Return the query as a string of SQL with the parameter values
substituted in (use sql_with_params() to see the unsubstituted string).
Parameter values won't necessarily be quoted correctly, since that is
done by the database interface at execution time.
"""
sql, params = self.sql_with_params()
return sql % params
def sql_with_params(self):
"""
Return the query as an SQL string and the parameters that will be
substituted into the query.
"""
return self.get_compiler(DEFAULT_DB_ALIAS).as_sql()
def __deepcopy__(self, memo):
"""Limit the amount of work when a Query is deepcopied."""
result = self.clone()
memo[id(self)] = result
return result
def get_compiler(self, using=None, connection=None, elide_empty=True):
if using is None and connection is None:
raise ValueError("Need either using or connection")
if using:
connection = connections[using]
return connection.ops.compiler(self.compiler)(
self, connection, using, elide_empty
)
def get_meta(self):
"""
Return the Options instance (the model._meta) from which to start
processing. Normally, this is self.model._meta, but it can be changed
by subclasses.
"""
if self.model:
return self.model._meta
def clone(self):
"""
Return a copy of the current Query. A lightweight alternative to
deepcopy().
"""
obj = Empty()
obj.__class__ = self.__class__
# Copy references to everything.
obj.__dict__ = self.__dict__.copy()
# Clone attributes that can't use shallow copy.
obj.alias_refcount = self.alias_refcount.copy()
obj.alias_map = self.alias_map.copy()
obj.external_aliases = self.external_aliases.copy()
obj.table_map = self.table_map.copy()
obj.where = self.where.clone()
obj.annotations = self.annotations.copy()
if self.annotation_select_mask is not None:
obj.annotation_select_mask = self.annotation_select_mask.copy()
if self.combined_queries:
obj.combined_queries = tuple(
[query.clone() for query in self.combined_queries]
)
# _annotation_select_cache cannot be copied, as doing so breaks the
# (necessary) state in which both annotations and
# _annotation_select_cache point to the same underlying objects.
# It will get re-populated in the cloned queryset the next time it's
# used.
obj._annotation_select_cache = None
obj.extra = self.extra.copy()
if self.extra_select_mask is not None:
obj.extra_select_mask = self.extra_select_mask.copy()
if self._extra_select_cache is not None:
obj._extra_select_cache = self._extra_select_cache.copy()
if self.select_related is not False:
# Use deepcopy because select_related stores fields in nested
# dicts.
obj.select_related = copy.deepcopy(obj.select_related)
if "subq_aliases" in self.__dict__:
obj.subq_aliases = self.subq_aliases.copy()
obj.used_aliases = self.used_aliases.copy()
obj._filtered_relations = self._filtered_relations.copy()
# Clear the cached_property, if it exists.
obj.__dict__.pop("base_table", None)
return obj
def chain(self, klass=None):
"""
Return a copy of the current Query that's ready for another operation.
The klass argument changes the type of the Query, e.g. UpdateQuery.
"""
obj = self.clone()
if klass and obj.__class__ != klass:
obj.__class__ = klass
if not obj.filter_is_sticky:
obj.used_aliases = set()
obj.filter_is_sticky = False
if hasattr(obj, "_setup_query"):
obj._setup_query()
return obj
def relabeled_clone(self, change_map):
clone = self.clone()
clone.change_aliases(change_map)
return clone
def _get_col(self, target, field, alias):
if not self.alias_cols:
alias = None
return target.get_col(alias, field)
def get_aggregation(self, using, aggregate_exprs):
"""
Return the dictionary with the values of the existing aggregations.
"""
if not aggregate_exprs:
return {}
# Store annotation mask prior to temporarily adding aggregations for
# resolving purpose to facilitate their subsequent removal.
refs_subquery = False
replacements = {}
annotation_select_mask = self.annotation_select_mask
for alias, aggregate_expr in aggregate_exprs.items():
self.check_alias(alias)
aggregate = aggregate_expr.resolve_expression(
self, allow_joins=True, reuse=None, summarize=True
)
if not aggregate.contains_aggregate:
raise TypeError("%s is not an aggregate expression" % alias)
# Temporarily add aggregate to annotations to allow remaining
# members of `aggregates` to resolve against each others.
self.append_annotation_mask([alias])
refs_subquery |= any(
getattr(self.annotations[ref], "subquery", False)
for ref in aggregate.get_refs()
)
aggregate = aggregate.replace_expressions(replacements)
self.annotations[alias] = aggregate
replacements[Ref(alias, aggregate)] = aggregate
# Stash resolved aggregates now that they have been allowed to resolve
# against each other.
aggregates = {alias: self.annotations.pop(alias) for alias in aggregate_exprs}
self.set_annotation_mask(annotation_select_mask)
# Existing usage of aggregation can be determined by the presence of
# selected aggregates but also by filters against aliased aggregates.
_, having, qualify = self.where.split_having_qualify()
has_existing_aggregation = (
any(
getattr(annotation, "contains_aggregate", True)
for annotation in self.annotations.values()
)
or having
)
# Decide if we need to use a subquery.
#
# Existing aggregations would cause incorrect results as
# get_aggregation() must produce just one result and thus must not use
# GROUP BY.
#
# If the query has limit or distinct, or uses set operations, then
# those operations must be done in a subquery so that the query
# aggregates on the limit and/or distinct results instead of applying
# the distinct and limit after the aggregation.
if (
isinstance(self.group_by, tuple)
or self.is_sliced
or has_existing_aggregation
or refs_subquery
or qualify
or self.distinct
or self.combinator
):
from django.db.models.sql.subqueries import AggregateQuery
inner_query = self.clone()
inner_query.subquery = True
outer_query = AggregateQuery(self.model, inner_query)
inner_query.select_for_update = False
inner_query.select_related = False
inner_query.set_annotation_mask(self.annotation_select)
# Queries with distinct_fields need ordering and when a limit is
# applied we must take the slice from the ordered query. Otherwise
# no need for ordering.
inner_query.clear_ordering(force=False)
if not inner_query.distinct:
# If the inner query uses default select and it has some
# aggregate annotations, then we must make sure the inner
# query is grouped by the main model's primary key. However,
# clearing the select clause can alter results if distinct is
# used.
if inner_query.default_cols and has_existing_aggregation:
inner_query.group_by = (
self.model._meta.pk.get_col(inner_query.get_initial_alias()),
)
inner_query.default_cols = False
if not qualify:
# Mask existing annotations that are not referenced by
# aggregates to be pushed to the outer query unless
# filtering against window functions is involved as it
# requires complex realising.
annotation_mask = set()
if isinstance(self.group_by, tuple):
for expr in self.group_by:
annotation_mask |= expr.get_refs()
for aggregate in aggregates.values():
annotation_mask |= aggregate.get_refs()
inner_query.set_annotation_mask(annotation_mask)
# Add aggregates to the outer AggregateQuery. This requires making
# sure all columns referenced by the aggregates are selected in the
# inner query. It is achieved by retrieving all column references
# by the aggregates, explicitly selecting them in the inner query,
# and making sure the aggregates are repointed to them.
col_refs = {}
for alias, aggregate in aggregates.items():
replacements = {}
for col in self._gen_cols([aggregate], resolve_refs=False):
if not (col_ref := col_refs.get(col)):
index = len(col_refs) + 1
col_alias = f"__col{index}"
col_ref = Ref(col_alias, col)
col_refs[col] = col_ref
inner_query.annotations[col_alias] = col
inner_query.append_annotation_mask([col_alias])
replacements[col] = col_ref
outer_query.annotations[alias] = aggregate.replace_expressions(
replacements
)
if (
inner_query.select == ()
and not inner_query.default_cols
and not inner_query.annotation_select_mask
):
# In case of Model.objects[0:3].count(), there would be no
# field selected in the inner query, yet we must use a subquery.
# So, make sure at least one field is selected.
inner_query.select = (
self.model._meta.pk.get_col(inner_query.get_initial_alias()),
)
else:
outer_query = self
self.select = ()
self.default_cols = False
self.extra = {}
if self.annotations:
# Inline reference to existing annotations and mask them as
# they are unnecessary given only the summarized aggregations
# are requested.
replacements = {
Ref(alias, annotation): annotation
for alias, annotation in self.annotations.items()
}
self.annotations = {
alias: aggregate.replace_expressions(replacements)
for alias, aggregate in aggregates.items()
}
else:
self.annotations = aggregates
self.set_annotation_mask(aggregates)
empty_set_result = [
expression.empty_result_set_value
for expression in outer_query.annotation_select.values()
]
elide_empty = not any(result is NotImplemented for result in empty_set_result)
outer_query.clear_ordering(force=True)
outer_query.clear_limits()
outer_query.select_for_update = False
outer_query.select_related = False
compiler = outer_query.get_compiler(using, elide_empty=elide_empty)
result = compiler.execute_sql(SINGLE)
if result is None:
result = empty_set_result
else:
converters = compiler.get_converters(outer_query.annotation_select.values())
result = next(compiler.apply_converters((result,), converters))
return dict(zip(outer_query.annotation_select, result))
def get_count(self, using):
"""
Perform a COUNT() query using the current filter constraints.
"""
obj = self.clone()
return obj.get_aggregation(using, {"__count": Count("*")})["__count"]
def has_filters(self):
return self.where
def exists(self, limit=True):
q = self.clone()
if not (q.distinct and q.is_sliced):
if q.group_by is True:
q.add_fields(
(f.attname for f in self.model._meta.concrete_fields), False
)
# Disable GROUP BY aliases to avoid orphaning references to the
# SELECT clause which is about to be cleared.
q.set_group_by(allow_aliases=False)
q.clear_select_clause()
if q.combined_queries and q.combinator == "union":
q.combined_queries = tuple(
combined_query.exists(limit=False)
for combined_query in q.combined_queries
)
q.clear_ordering(force=True)
if limit:
q.set_limits(high=1)
q.add_annotation(Value(1), "a")
return q
def has_results(self, using):
q = self.exists(using)
compiler = q.get_compiler(using=using)
return compiler.has_results()
def explain(self, using, format=None, **options):
q = self.clone()
for option_name in options:
if (
not EXPLAIN_OPTIONS_PATTERN.fullmatch(option_name)
or "--" in option_name
):
raise ValueError(f"Invalid option name: {option_name!r}.")
q.explain_info = ExplainInfo(format, options)
compiler = q.get_compiler(using=using)
return "\n".join(compiler.explain_query())
def combine(self, rhs, connector):
"""
Merge the 'rhs' query into the current one (with any 'rhs' effects
being applied *after* (that is, "to the right of") anything in the
current query. 'rhs' is not modified during a call to this function.
The 'connector' parameter describes how to connect filters from the
'rhs' query.
"""
if self.model != rhs.model:
raise TypeError("Cannot combine queries on two different base models.")
if self.is_sliced:
raise TypeError("Cannot combine queries once a slice has been taken.")
if self.distinct != rhs.distinct:
raise TypeError("Cannot combine a unique query with a non-unique query.")
if self.distinct_fields != rhs.distinct_fields:
raise TypeError("Cannot combine queries with different distinct fields.")
# If lhs and rhs shares the same alias prefix, it is possible to have
# conflicting alias changes like T4 -> T5, T5 -> T6, which might end up
# as T4 -> T6 while combining two querysets. To prevent this, change an
# alias prefix of the rhs and update current aliases accordingly,
# except if the alias is the base table since it must be present in the
# query on both sides.
initial_alias = self.get_initial_alias()
rhs.bump_prefix(self, exclude={initial_alias})
# Work out how to relabel the rhs aliases, if necessary.
change_map = {}
conjunction = connector == AND
# Determine which existing joins can be reused. When combining the
# query with AND we must recreate all joins for m2m filters. When
# combining with OR we can reuse joins. The reason is that in AND
# case a single row can't fulfill a condition like:
# revrel__col=1 & revrel__col=2
# But, there might be two different related rows matching this
# condition. In OR case a single True is enough, so single row is
# enough, too.
#
# Note that we will be creating duplicate joins for non-m2m joins in
# the AND case. The results will be correct but this creates too many
# joins. This is something that could be fixed later on.
reuse = set() if conjunction else set(self.alias_map)
joinpromoter = JoinPromoter(connector, 2, False)
joinpromoter.add_votes(
j for j in self.alias_map if self.alias_map[j].join_type == INNER
)
rhs_votes = set()
# Now, add the joins from rhs query into the new query (skipping base
# table).
rhs_tables = list(rhs.alias_map)[1:]
for alias in rhs_tables:
join = rhs.alias_map[alias]
# If the left side of the join was already relabeled, use the
# updated alias.
join = join.relabeled_clone(change_map)
new_alias = self.join(join, reuse=reuse)
if join.join_type == INNER:
rhs_votes.add(new_alias)
# We can't reuse the same join again in the query. If we have two
# distinct joins for the same connection in rhs query, then the
# combined query must have two joins, too.
reuse.discard(new_alias)
if alias != new_alias:
change_map[alias] = new_alias
if not rhs.alias_refcount[alias]:
# The alias was unused in the rhs query. Unref it so that it
# will be unused in the new query, too. We have to add and
# unref the alias so that join promotion has information of
# the join type for the unused alias.
self.unref_alias(new_alias)
joinpromoter.add_votes(rhs_votes)
joinpromoter.update_join_types(self)
# Combine subqueries aliases to ensure aliases relabelling properly
# handle subqueries when combining where and select clauses.
self.subq_aliases |= rhs.subq_aliases
# Now relabel a copy of the rhs where-clause and add it to the current
# one.
w = rhs.where.clone()
w.relabel_aliases(change_map)
self.where.add(w, connector)
# Selection columns and extra extensions are those provided by 'rhs'.
if rhs.select:
self.set_select([col.relabeled_clone(change_map) for col in rhs.select])
else:
self.select = ()
if connector == OR:
# It would be nice to be able to handle this, but the queries don't
# really make sense (or return consistent value sets). Not worth
# the extra complexity when you can write a real query instead.
if self.extra and rhs.extra:
raise ValueError(
"When merging querysets using 'or', you cannot have "
"extra(select=...) on both sides."
)
self.extra.update(rhs.extra)
extra_select_mask = set()
if self.extra_select_mask is not None:
extra_select_mask.update(self.extra_select_mask)
if rhs.extra_select_mask is not None:
extra_select_mask.update(rhs.extra_select_mask)
if extra_select_mask:
self.set_extra_mask(extra_select_mask)
self.extra_tables += rhs.extra_tables
# Ordering uses the 'rhs' ordering, unless it has none, in which case
# the current ordering is used.
self.order_by = rhs.order_by or self.order_by
self.extra_order_by = rhs.extra_order_by or self.extra_order_by
def _get_defer_select_mask(self, opts, mask, select_mask=None):
if select_mask is None:
select_mask = {}
select_mask[opts.pk] = {}
# All concrete fields that are not part of the defer mask must be
# loaded. If a relational field is encountered it gets added to the
# mask for it be considered if `select_related` and the cycle continues
# by recursively caling this function.
for field in opts.concrete_fields:
field_mask = mask.pop(field.name, None)
field_att_mask = mask.pop(field.attname, None)
if field_mask is None and field_att_mask is None:
select_mask.setdefault(field, {})
elif field_mask:
if not field.is_relation:
raise FieldError(next(iter(field_mask)))
field_select_mask = select_mask.setdefault(field, {})
related_model = field.remote_field.model._meta.concrete_model
self._get_defer_select_mask(
related_model._meta, field_mask, field_select_mask
)
# Remaining defer entries must be references to reverse relationships.
# The following code is expected to raise FieldError if it encounters
# a malformed defer entry.
for field_name, field_mask in mask.items():
if filtered_relation := self._filtered_relations.get(field_name):
relation = opts.get_field(filtered_relation.relation_name)
field_select_mask = select_mask.setdefault((field_name, relation), {})
field = relation.field
else:
reverse_rel = opts.get_field(field_name)
# While virtual fields such as many-to-many and generic foreign
# keys cannot be effectively deferred we've historically
# allowed them to be passed to QuerySet.defer(). Ignore such
# field references until a layer of validation at mask
# alteration time will be implemented eventually.
if not hasattr(reverse_rel, "field"):
continue
field = reverse_rel.field
field_select_mask = select_mask.setdefault(field, {})
related_model = field.model._meta.concrete_model
self._get_defer_select_mask(
related_model._meta, field_mask, field_select_mask
)
return select_mask
def _get_only_select_mask(self, opts, mask, select_mask=None):
if select_mask is None:
select_mask = {}
select_mask[opts.pk] = {}
# Only include fields mentioned in the mask.
for field_name, field_mask in mask.items():
field = opts.get_field(field_name)
# Retrieve the actual field associated with reverse relationships
# as that's what is expected in the select mask.
if field in opts.related_objects:
field_key = field.field
else:
field_key = field
field_select_mask = select_mask.setdefault(field_key, {})
if field_mask:
if not field.is_relation:
raise FieldError(next(iter(field_mask)))
related_model = field.remote_field.model._meta.concrete_model
self._get_only_select_mask(
related_model._meta, field_mask, field_select_mask
)
return select_mask
def get_select_mask(self):
"""
Convert the self.deferred_loading data structure to an alternate data
structure, describing the field that *will* be loaded. This is used to
compute the columns to select from the database and also by the
QuerySet class to work out which fields are being initialized on each
model. Models that have all their fields included aren't mentioned in
the result, only those that have field restrictions in place.
"""
field_names, defer = self.deferred_loading
if not field_names:
return {}
mask = {}
for field_name in field_names:
part_mask = mask
for part in field_name.split(LOOKUP_SEP):
part_mask = part_mask.setdefault(part, {})
opts = self.get_meta()
if defer:
return self._get_defer_select_mask(opts, mask)
return self._get_only_select_mask(opts, mask)
def table_alias(self, table_name, create=False, filtered_relation=None):
"""
Return a table alias for the given table_name and whether this is a
new alias or not.
If 'create' is true, a new alias is always created. Otherwise, the
most recently created alias for the table (if one exists) is reused.
"""
alias_list = self.table_map.get(table_name)
if not create and alias_list:
alias = alias_list[0]
self.alias_refcount[alias] += 1
return alias, False
# Create a new alias for this table.
if alias_list:
alias = "%s%d" % (self.alias_prefix, len(self.alias_map) + 1)
alias_list.append(alias)
else:
# The first occurrence of a table uses the table name directly.
alias = (
filtered_relation.alias if filtered_relation is not None else table_name
)
self.table_map[table_name] = [alias]
self.alias_refcount[alias] = 1
return alias, True
def ref_alias(self, alias):
"""Increases the reference count for this alias."""
self.alias_refcount[alias] += 1
def unref_alias(self, alias, amount=1):
"""Decreases the reference count for this alias."""
self.alias_refcount[alias] -= amount
def promote_joins(self, aliases):
"""
Promote recursively the join type of given aliases and its children to
an outer join. If 'unconditional' is False, only promote the join if
it is nullable or the parent join is an outer join.
The children promotion is done to avoid join chains that contain a LOUTER
b INNER c. So, if we have currently a INNER b INNER c and a->b is promoted,
then we must also promote b->c automatically, or otherwise the promotion
of a->b doesn't actually change anything in the query results.
"""
aliases = list(aliases)
while aliases:
alias = aliases.pop(0)
if self.alias_map[alias].join_type is None:
# This is the base table (first FROM entry) - this table
# isn't really joined at all in the query, so we should not
# alter its join type.
continue
# Only the first alias (skipped above) should have None join_type
assert self.alias_map[alias].join_type is not None
parent_alias = self.alias_map[alias].parent_alias
parent_louter = (
parent_alias and self.alias_map[parent_alias].join_type == LOUTER
)
already_louter = self.alias_map[alias].join_type == LOUTER
if (self.alias_map[alias].nullable or parent_louter) and not already_louter:
self.alias_map[alias] = self.alias_map[alias].promote()
# Join type of 'alias' changed, so re-examine all aliases that
# refer to this one.
aliases.extend(
join
for join in self.alias_map
if self.alias_map[join].parent_alias == alias
and join not in aliases
)
def demote_joins(self, aliases):
"""
Change join type from LOUTER to INNER for all joins in aliases.
Similarly to promote_joins(), this method must ensure no join chains
containing first an outer, then an inner join are generated. If we
are demoting b->c join in chain a LOUTER b LOUTER c then we must
demote a->b automatically, or otherwise the demotion of b->c doesn't
actually change anything in the query results. .
"""
aliases = list(aliases)
while aliases:
alias = aliases.pop(0)
if self.alias_map[alias].join_type == LOUTER:
self.alias_map[alias] = self.alias_map[alias].demote()
parent_alias = self.alias_map[alias].parent_alias
if self.alias_map[parent_alias].join_type == INNER:
aliases.append(parent_alias)
def reset_refcounts(self, to_counts):
"""
Reset reference counts for aliases so that they match the value passed
in `to_counts`.
"""
for alias, cur_refcount in self.alias_refcount.copy().items():
unref_amount = cur_refcount - to_counts.get(alias, 0)
self.unref_alias(alias, unref_amount)
def change_aliases(self, change_map):
"""
Change the aliases in change_map (which maps old-alias -> new-alias),
relabelling any references to them in select columns and the where
clause.
"""
# If keys and values of change_map were to intersect, an alias might be
# updated twice (e.g. T4 -> T5, T5 -> T6, so also T4 -> T6) depending
# on their order in change_map.
assert set(change_map).isdisjoint(change_map.values())
# 1. Update references in "select" (normal columns plus aliases),
# "group by" and "where".
self.where.relabel_aliases(change_map)
if isinstance(self.group_by, tuple):
self.group_by = tuple(
[col.relabeled_clone(change_map) for col in self.group_by]
)
self.select = tuple([col.relabeled_clone(change_map) for col in self.select])
self.annotations = self.annotations and {
key: col.relabeled_clone(change_map)
for key, col in self.annotations.items()
}
# 2. Rename the alias in the internal table/alias datastructures.
for old_alias, new_alias in change_map.items():
if old_alias not in self.alias_map:
continue
alias_data = self.alias_map[old_alias].relabeled_clone(change_map)
self.alias_map[new_alias] = alias_data
self.alias_refcount[new_alias] = self.alias_refcount[old_alias]
del self.alias_refcount[old_alias]
del self.alias_map[old_alias]
table_aliases = self.table_map[alias_data.table_name]
for pos, alias in enumerate(table_aliases):
if alias == old_alias:
table_aliases[pos] = new_alias
break
self.external_aliases = {
# Table is aliased or it's being changed and thus is aliased.
change_map.get(alias, alias): (aliased or alias in change_map)
for alias, aliased in self.external_aliases.items()
}
def bump_prefix(self, other_query, exclude=None):
"""
Change the alias prefix to the next letter in the alphabet in a way
that the other query's aliases and this query's aliases will not
conflict. Even tables that previously had no alias will get an alias
after this call. To prevent changing aliases use the exclude parameter.
"""
def prefix_gen():
"""
Generate a sequence of characters in alphabetical order:
-> 'A', 'B', 'C', ...
When the alphabet is finished, the sequence will continue with the
Cartesian product:
-> 'AA', 'AB', 'AC', ...
"""
alphabet = ascii_uppercase
prefix = chr(ord(self.alias_prefix) + 1)
yield prefix
for n in count(1):
seq = alphabet[alphabet.index(prefix) :] if prefix else alphabet
for s in product(seq, repeat=n):
yield "".join(s)
prefix = None
if self.alias_prefix != other_query.alias_prefix:
# No clashes between self and outer query should be possible.
return
# Explicitly avoid infinite loop. The constant divider is based on how
# much depth recursive subquery references add to the stack. This value
# might need to be adjusted when adding or removing function calls from
# the code path in charge of performing these operations.
local_recursion_limit = sys.getrecursionlimit() // 16
for pos, prefix in enumerate(prefix_gen()):
if prefix not in self.subq_aliases:
self.alias_prefix = prefix
break
if pos > local_recursion_limit:
raise RecursionError(
"Maximum recursion depth exceeded: too many subqueries."
)
self.subq_aliases = self.subq_aliases.union([self.alias_prefix])
other_query.subq_aliases = other_query.subq_aliases.union(self.subq_aliases)
if exclude is None:
exclude = {}
self.change_aliases(
{
alias: "%s%d" % (self.alias_prefix, pos)
for pos, alias in enumerate(self.alias_map)
if alias not in exclude
}
)
def get_initial_alias(self):
"""
Return the first alias for this query, after increasing its reference
count.
"""
if self.alias_map:
alias = self.base_table
self.ref_alias(alias)
elif self.model:
alias = self.join(self.base_table_class(self.get_meta().db_table, None))
else:
alias = None
return alias
def count_active_tables(self):
"""
Return the number of tables in this query with a non-zero reference
count. After execution, the reference counts are zeroed, so tables
added in compiler will not be seen by this method.
"""
return len([1 for count in self.alias_refcount.values() if count])
def join(self, join, reuse=None, reuse_with_filtered_relation=False):
"""
Return an alias for the 'join', either reusing an existing alias for
that join or creating a new one. 'join' is either a base_table_class or
join_class.
The 'reuse' parameter can be either None which means all joins are
reusable, or it can be a set containing the aliases that can be reused.
The 'reuse_with_filtered_relation' parameter is used when computing
FilteredRelation instances.
A join is always created as LOUTER if the lhs alias is LOUTER to make
sure chains like t1 LOUTER t2 INNER t3 aren't generated. All new
joins are created as LOUTER if the join is nullable.
"""
if reuse_with_filtered_relation and reuse:
reuse_aliases = [
a for a, j in self.alias_map.items() if a in reuse and j.equals(join)
]
else:
reuse_aliases = [
a
for a, j in self.alias_map.items()
if (reuse is None or a in reuse) and j == join
]
if reuse_aliases:
if join.table_alias in reuse_aliases:
reuse_alias = join.table_alias
else:
# Reuse the most recent alias of the joined table
# (a many-to-many relation may be joined multiple times).
reuse_alias = reuse_aliases[-1]
self.ref_alias(reuse_alias)
return reuse_alias
# No reuse is possible, so we need a new alias.
alias, _ = self.table_alias(
join.table_name, create=True, filtered_relation=join.filtered_relation
)
if join.join_type:
if self.alias_map[join.parent_alias].join_type == LOUTER or join.nullable:
join_type = LOUTER
else:
join_type = INNER
join.join_type = join_type
join.table_alias = alias
self.alias_map[alias] = join
return alias
def join_parent_model(self, opts, model, alias, seen):
"""
Make sure the given 'model' is joined in the query. If 'model' isn't
a parent of 'opts' or if it is None this method is a no-op.
The 'alias' is the root alias for starting the join, 'seen' is a dict
of model -> alias of existing joins. It must also contain a mapping
of None -> some alias. This will be returned in the no-op case.
"""
if model in seen:
return seen[model]
chain = opts.get_base_chain(model)
if not chain:
return alias
curr_opts = opts
for int_model in chain:
if int_model in seen:
curr_opts = int_model._meta
alias = seen[int_model]
continue
# Proxy model have elements in base chain
# with no parents, assign the new options
# object and skip to the next base in that
# case
if not curr_opts.parents[int_model]:
curr_opts = int_model._meta
continue
link_field = curr_opts.get_ancestor_link(int_model)
join_info = self.setup_joins([link_field.name], curr_opts, alias)
curr_opts = int_model._meta
alias = seen[int_model] = join_info.joins[-1]
return alias or seen[None]
def check_alias(self, alias):
if FORBIDDEN_ALIAS_PATTERN.search(alias):
raise ValueError(
"Column aliases cannot contain whitespace characters, quotation marks, "
"semicolons, or SQL comments."
)
def add_annotation(self, annotation, alias, select=True):
"""Add a single annotation expression to the Query."""
self.check_alias(alias)
annotation = annotation.resolve_expression(self, allow_joins=True, reuse=None)
if select:
self.append_annotation_mask([alias])
else:
self.set_annotation_mask(set(self.annotation_select).difference({alias}))
self.annotations[alias] = annotation
def resolve_expression(self, query, *args, **kwargs):
clone = self.clone()
# Subqueries need to use a different set of aliases than the outer query.
clone.bump_prefix(query)
clone.subquery = True
clone.where.resolve_expression(query, *args, **kwargs)
# Resolve combined queries.
if clone.combinator:
clone.combined_queries = tuple(
[
combined_query.resolve_expression(query, *args, **kwargs)
for combined_query in clone.combined_queries
]
)
for key, value in clone.annotations.items():
resolved = value.resolve_expression(query, *args, **kwargs)
if hasattr(resolved, "external_aliases"):
resolved.external_aliases.update(clone.external_aliases)
clone.annotations[key] = resolved
# Outer query's aliases are considered external.
for alias, table in query.alias_map.items():
clone.external_aliases[alias] = (
isinstance(table, Join)
and table.join_field.related_model._meta.db_table != alias
) or (
isinstance(table, BaseTable) and table.table_name != table.table_alias
)
return clone
def get_external_cols(self):
exprs = chain(self.annotations.values(), self.where.children)
return [
col
for col in self._gen_cols(exprs, include_external=True)
if col.alias in self.external_aliases
]
def get_group_by_cols(self, wrapper=None):
# If wrapper is referenced by an alias for an explicit GROUP BY through
# values() a reference to this expression and not the self must be
# returned to ensure external column references are not grouped against
# as well.
external_cols = self.get_external_cols()
if any(col.possibly_multivalued for col in external_cols):
return [wrapper or self]
return external_cols
def as_sql(self, compiler, connection):
# Some backends (e.g. Oracle) raise an error when a subquery contains
# unnecessary ORDER BY clause.
if (
self.subquery
and not connection.features.ignores_unnecessary_order_by_in_subqueries
):
self.clear_ordering(force=False)
for query in self.combined_queries:
query.clear_ordering(force=False)
sql, params = self.get_compiler(connection=connection).as_sql()
if self.subquery:
sql = "(%s)" % sql
return sql, params
def resolve_lookup_value(self, value, can_reuse, allow_joins):
if hasattr(value, "resolve_expression"):
value = value.resolve_expression(
self,
reuse=can_reuse,
allow_joins=allow_joins,
)
elif isinstance(value, (list, tuple)):
# The items of the iterable may be expressions and therefore need
# to be resolved independently.
values = (
self.resolve_lookup_value(sub_value, can_reuse, allow_joins)
for sub_value in value
)
type_ = type(value)
if hasattr(type_, "_make"): # namedtuple
return type_(*values)
return type_(values)
return value
def solve_lookup_type(self, lookup, summarize=False):
"""
Solve the lookup type from the lookup (e.g.: 'foobar__id__icontains').
"""
lookup_splitted = lookup.split(LOOKUP_SEP)
if self.annotations:
annotation, expression_lookups = refs_expression(
lookup_splitted, self.annotations
)
if annotation:
expression = self.annotations[annotation]
if summarize:
expression = Ref(annotation, expression)
return expression_lookups, (), expression
_, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta())
field_parts = lookup_splitted[0 : len(lookup_splitted) - len(lookup_parts)]
if len(lookup_parts) > 1 and not field_parts:
raise FieldError(
'Invalid lookup "%s" for model %s".'
% (lookup, self.get_meta().model.__name__)
)
return lookup_parts, field_parts, False
def check_query_object_type(self, value, opts, field):
"""
Check whether the object passed while querying is of the correct type.
If not, raise a ValueError specifying the wrong object.
"""
if hasattr(value, "_meta"):
if not check_rel_lookup_compatibility(value._meta.model, opts, field):
raise ValueError(
'Cannot query "%s": Must be "%s" instance.'
% (value, opts.object_name)
)
def check_related_objects(self, field, value, opts):
"""Check the type of object passed to query relations."""
if field.is_relation:
# Check that the field and the queryset use the same model in a
# query like .filter(author=Author.objects.all()). For example, the
# opts would be Author's (from the author field) and value.model
# would be Author.objects.all() queryset's .model (Author also).
# The field is the related field on the lhs side.
if (
isinstance(value, Query)
and not value.has_select_fields
and not check_rel_lookup_compatibility(value.model, opts, field)
):
raise ValueError(
'Cannot use QuerySet for "%s": Use a QuerySet for "%s".'
% (value.model._meta.object_name, opts.object_name)
)
elif hasattr(value, "_meta"):
self.check_query_object_type(value, opts, field)
elif hasattr(value, "__iter__"):
for v in value:
self.check_query_object_type(v, opts, field)
def check_filterable(self, expression):
"""Raise an error if expression cannot be used in a WHERE clause."""
if hasattr(expression, "resolve_expression") and not getattr(
expression, "filterable", True
):
raise NotSupportedError(
expression.__class__.__name__ + " is disallowed in the filter "
"clause."
)
if hasattr(expression, "get_source_expressions"):
for expr in expression.get_source_expressions():
self.check_filterable(expr)
def build_lookup(self, lookups, lhs, rhs):
"""
Try to extract transforms and lookup from given lhs.
The lhs value is something that works like SQLExpression.
The rhs value is what the lookup is going to compare against.
The lookups is a list of names to extract using get_lookup()
and get_transform().
"""
# __exact is the default lookup if one isn't given.
*transforms, lookup_name = lookups or ["exact"]
for name in transforms:
lhs = self.try_transform(lhs, name)
# First try get_lookup() so that the lookup takes precedence if the lhs
# supports both transform and lookup for the name.
lookup_class = lhs.get_lookup(lookup_name)
if not lookup_class:
# A lookup wasn't found. Try to interpret the name as a transform
# and do an Exact lookup against it.
lhs = self.try_transform(lhs, lookup_name)
lookup_name = "exact"
lookup_class = lhs.get_lookup(lookup_name)
if not lookup_class:
return
lookup = lookup_class(lhs, rhs)
# Interpret '__exact=None' as the sql 'is NULL'; otherwise, reject all
# uses of None as a query value unless the lookup supports it.
if lookup.rhs is None and not lookup.can_use_none_as_rhs:
if lookup_name not in ("exact", "iexact"):
raise ValueError("Cannot use None as a query value")
return lhs.get_lookup("isnull")(lhs, True)
# For Oracle '' is equivalent to null. The check must be done at this
# stage because join promotion can't be done in the compiler. Using
# DEFAULT_DB_ALIAS isn't nice but it's the best that can be done here.
# A similar thing is done in is_nullable(), too.
if (
lookup_name == "exact"
and lookup.rhs == ""
and connections[DEFAULT_DB_ALIAS].features.interprets_empty_strings_as_nulls
):
return lhs.get_lookup("isnull")(lhs, True)
return lookup
def try_transform(self, lhs, name):
"""
Helper method for build_lookup(). Try to fetch and initialize
a transform for name parameter from lhs.
"""
transform_class = lhs.get_transform(name)
if transform_class:
return transform_class(lhs)
else:
output_field = lhs.output_field.__class__
suggested_lookups = difflib.get_close_matches(
name, lhs.output_field.get_lookups()
)
if suggested_lookups:
suggestion = ", perhaps you meant %s?" % " or ".join(suggested_lookups)
else:
suggestion = "."
raise FieldError(
"Unsupported lookup '%s' for %s or join on the field not "
"permitted%s" % (name, output_field.__name__, suggestion)
)
def build_filter(
self,
filter_expr,
branch_negated=False,
current_negated=False,
can_reuse=None,
allow_joins=True,
split_subq=True,
reuse_with_filtered_relation=False,
check_filterable=True,
summarize=False,
):
"""
Build a WhereNode for a single filter clause but don't add it
to this Query. Query.add_q() will then add this filter to the where
Node.
The 'branch_negated' tells us if the current branch contains any
negations. This will be used to determine if subqueries are needed.
The 'current_negated' is used to determine if the current filter is
negated or not and this will be used to determine if IS NULL filtering
is needed.
The difference between current_negated and branch_negated is that
branch_negated is set on first negation, but current_negated is
flipped for each negation.
Note that add_filter will not do any negating itself, that is done
upper in the code by add_q().
The 'can_reuse' is a set of reusable joins for multijoins.
If 'reuse_with_filtered_relation' is True, then only joins in can_reuse
will be reused.
The method will create a filter clause that can be added to the current
query. However, if the filter isn't added to the query then the caller
is responsible for unreffing the joins used.
"""
if isinstance(filter_expr, dict):
raise FieldError("Cannot parse keyword query as dict")
if isinstance(filter_expr, Q):
return self._add_q(
filter_expr,
branch_negated=branch_negated,
current_negated=current_negated,
used_aliases=can_reuse,
allow_joins=allow_joins,
split_subq=split_subq,
check_filterable=check_filterable,
summarize=summarize,
)
if hasattr(filter_expr, "resolve_expression"):
if not getattr(filter_expr, "conditional", False):
raise TypeError("Cannot filter against a non-conditional expression.")
condition = filter_expr.resolve_expression(
self, allow_joins=allow_joins, summarize=summarize
)
if not isinstance(condition, Lookup):
condition = self.build_lookup(["exact"], condition, True)
return WhereNode([condition], connector=AND), []
arg, value = filter_expr
if not arg:
raise FieldError("Cannot parse keyword query %r" % arg)
lookups, parts, reffed_expression = self.solve_lookup_type(arg, summarize)
if check_filterable:
self.check_filterable(reffed_expression)
if not allow_joins and len(parts) > 1:
raise FieldError("Joined field references are not permitted in this query")
pre_joins = self.alias_refcount.copy()
value = self.resolve_lookup_value(value, can_reuse, allow_joins)
used_joins = {
k for k, v in self.alias_refcount.items() if v > pre_joins.get(k, 0)
}
if check_filterable:
self.check_filterable(value)
if reffed_expression:
condition = self.build_lookup(lookups, reffed_expression, value)
return WhereNode([condition], connector=AND), []
opts = self.get_meta()
alias = self.get_initial_alias()
allow_many = not branch_negated or not split_subq
try:
join_info = self.setup_joins(
parts,
opts,
alias,
can_reuse=can_reuse,
allow_many=allow_many,
reuse_with_filtered_relation=reuse_with_filtered_relation,
)
# Prevent iterator from being consumed by check_related_objects()
if isinstance(value, Iterator):
value = list(value)
self.check_related_objects(join_info.final_field, value, join_info.opts)
# split_exclude() needs to know which joins were generated for the
# lookup parts
self._lookup_joins = join_info.joins
except MultiJoin as e:
return self.split_exclude(filter_expr, can_reuse, e.names_with_path)
# Update used_joins before trimming since they are reused to determine
# which joins could be later promoted to INNER.
used_joins.update(join_info.joins)
targets, alias, join_list = self.trim_joins(
join_info.targets, join_info.joins, join_info.path
)
if can_reuse is not None:
can_reuse.update(join_list)
if join_info.final_field.is_relation:
if len(targets) == 1:
col = self._get_col(targets[0], join_info.final_field, alias)
else:
col = MultiColSource(
alias, targets, join_info.targets, join_info.final_field
)
else:
col = self._get_col(targets[0], join_info.final_field, alias)
condition = self.build_lookup(lookups, col, value)
lookup_type = condition.lookup_name
clause = WhereNode([condition], connector=AND)
require_outer = (
lookup_type == "isnull" and condition.rhs is True and not current_negated
)
if (
current_negated
and (lookup_type != "isnull" or condition.rhs is False)
and condition.rhs is not None
):
require_outer = True
if lookup_type != "isnull":
# The condition added here will be SQL like this:
# NOT (col IS NOT NULL), where the first NOT is added in
# upper layers of code. The reason for addition is that if col
# is null, then col != someval will result in SQL "unknown"
# which isn't the same as in Python. The Python None handling
# is wanted, and it can be gotten by
# (col IS NULL OR col != someval)
# <=>
# NOT (col IS NOT NULL AND col = someval).
if (
self.is_nullable(targets[0])
or self.alias_map[join_list[-1]].join_type == LOUTER
):
lookup_class = targets[0].get_lookup("isnull")
col = self._get_col(targets[0], join_info.targets[0], alias)
clause.add(lookup_class(col, False), AND)
# If someval is a nullable column, someval IS NOT NULL is
# added.
if isinstance(value, Col) and self.is_nullable(value.target):
lookup_class = value.target.get_lookup("isnull")
clause.add(lookup_class(value, False), AND)
return clause, used_joins if not require_outer else ()
def add_filter(self, filter_lhs, filter_rhs):
self.add_q(Q((filter_lhs, filter_rhs)))
def add_q(self, q_object):
"""
A preprocessor for the internal _add_q(). Responsible for doing final
join promotion.
"""
# For join promotion this case is doing an AND for the added q_object
# and existing conditions. So, any existing inner join forces the join
# type to remain inner. Existing outer joins can however be demoted.
# (Consider case where rel_a is LOUTER and rel_a__col=1 is added - if
# rel_a doesn't produce any rows, then the whole condition must fail.
# So, demotion is OK.
existing_inner = {
a for a in self.alias_map if self.alias_map[a].join_type == INNER
}
clause, _ = self._add_q(q_object, self.used_aliases)
if clause:
self.where.add(clause, AND)
self.demote_joins(existing_inner)
def build_where(self, filter_expr):
return self.build_filter(filter_expr, allow_joins=False)[0]
def clear_where(self):
self.where = WhereNode()
def _add_q(
self,
q_object,
used_aliases,
branch_negated=False,
current_negated=False,
allow_joins=True,
split_subq=True,
check_filterable=True,
summarize=False,
):
"""Add a Q-object to the current filter."""
connector = q_object.connector
current_negated ^= q_object.negated
branch_negated = branch_negated or q_object.negated
target_clause = WhereNode(connector=connector, negated=q_object.negated)
joinpromoter = JoinPromoter(
q_object.connector, len(q_object.children), current_negated
)
for child in q_object.children:
child_clause, needed_inner = self.build_filter(
child,
can_reuse=used_aliases,
branch_negated=branch_negated,
current_negated=current_negated,
allow_joins=allow_joins,
split_subq=split_subq,
check_filterable=check_filterable,
summarize=summarize,
)
joinpromoter.add_votes(needed_inner)
if child_clause:
target_clause.add(child_clause, connector)
needed_inner = joinpromoter.update_join_types(self)
return target_clause, needed_inner
def build_filtered_relation_q(
self, q_object, reuse, branch_negated=False, current_negated=False
):
"""Add a FilteredRelation object to the current filter."""
connector = q_object.connector
current_negated ^= q_object.negated
branch_negated = branch_negated or q_object.negated
target_clause = WhereNode(connector=connector, negated=q_object.negated)
for child in q_object.children:
if isinstance(child, Node):
child_clause = self.build_filtered_relation_q(
child,
reuse=reuse,
branch_negated=branch_negated,
current_negated=current_negated,
)
else:
child_clause, _ = self.build_filter(
child,
can_reuse=reuse,
branch_negated=branch_negated,
current_negated=current_negated,
allow_joins=True,
split_subq=False,
reuse_with_filtered_relation=True,
)
target_clause.add(child_clause, connector)
return target_clause
def add_filtered_relation(self, filtered_relation, alias):
filtered_relation.alias = alias
lookups = dict(get_children_from_q(filtered_relation.condition))
relation_lookup_parts, relation_field_parts, _ = self.solve_lookup_type(
filtered_relation.relation_name
)
if relation_lookup_parts:
raise ValueError(
"FilteredRelation's relation_name cannot contain lookups "
"(got %r)." % filtered_relation.relation_name
)
for lookup in chain(lookups):
lookup_parts, lookup_field_parts, _ = self.solve_lookup_type(lookup)
shift = 2 if not lookup_parts else 1
lookup_field_path = lookup_field_parts[:-shift]
for idx, lookup_field_part in enumerate(lookup_field_path):
if len(relation_field_parts) > idx:
if relation_field_parts[idx] != lookup_field_part:
raise ValueError(
"FilteredRelation's condition doesn't support "
"relations outside the %r (got %r)."
% (filtered_relation.relation_name, lookup)
)
else:
raise ValueError(
"FilteredRelation's condition doesn't support nested "
"relations deeper than the relation_name (got %r for "
"%r)." % (lookup, filtered_relation.relation_name)
)
self._filtered_relations[filtered_relation.alias] = filtered_relation
def names_to_path(self, names, opts, allow_many=True, fail_on_missing=False):
"""
Walk the list of names and turns them into PathInfo tuples. A single
name in 'names' can generate multiple PathInfos (m2m, for example).
'names' is the path of names to travel, 'opts' is the model Options we
start the name resolving from, 'allow_many' is as for setup_joins().
If fail_on_missing is set to True, then a name that can't be resolved
will generate a FieldError.
Return a list of PathInfo tuples. In addition return the final field
(the last used join field) and target (which is a field guaranteed to
contain the same value as the final field). Finally, return those names
that weren't found (which are likely transforms and the final lookup).
"""
path, names_with_path = [], []
for pos, name in enumerate(names):
cur_names_with_path = (name, [])
if name == "pk":
name = opts.pk.name
field = None
filtered_relation = None
try:
if opts is None:
raise FieldDoesNotExist
field = opts.get_field(name)
except FieldDoesNotExist:
if name in self.annotation_select:
field = self.annotation_select[name].output_field
elif name in self._filtered_relations and pos == 0:
filtered_relation = self._filtered_relations[name]
if LOOKUP_SEP in filtered_relation.relation_name:
parts = filtered_relation.relation_name.split(LOOKUP_SEP)
filtered_relation_path, field, _, _ = self.names_to_path(
parts,
opts,
allow_many,
fail_on_missing,
)
path.extend(filtered_relation_path[:-1])
else:
field = opts.get_field(filtered_relation.relation_name)
if field is not None:
# Fields that contain one-to-many relations with a generic
# model (like a GenericForeignKey) cannot generate reverse
# relations and therefore cannot be used for reverse querying.
if field.is_relation and not field.related_model:
raise FieldError(
"Field %r does not generate an automatic reverse "
"relation and therefore cannot be used for reverse "
"querying. If it is a GenericForeignKey, consider "
"adding a GenericRelation." % name
)
try:
model = field.model._meta.concrete_model
except AttributeError:
# QuerySet.annotate() may introduce fields that aren't
# attached to a model.
model = None
else:
# We didn't find the current field, so move position back
# one step.
pos -= 1
if pos == -1 or fail_on_missing:
available = sorted(
[
*get_field_names_from_opts(opts),
*self.annotation_select,
*self._filtered_relations,
]
)
raise FieldError(
"Cannot resolve keyword '%s' into field. "
"Choices are: %s" % (name, ", ".join(available))
)
break
# Check if we need any joins for concrete inheritance cases (the
# field lives in parent, but we are currently in one of its
# children)
if opts is not None and model is not opts.model:
path_to_parent = opts.get_path_to_parent(model)
if path_to_parent:
path.extend(path_to_parent)
cur_names_with_path[1].extend(path_to_parent)
opts = path_to_parent[-1].to_opts
if hasattr(field, "path_infos"):
if filtered_relation:
pathinfos = field.get_path_info(filtered_relation)
else:
pathinfos = field.path_infos
if not allow_many:
for inner_pos, p in enumerate(pathinfos):
if p.m2m:
cur_names_with_path[1].extend(pathinfos[0 : inner_pos + 1])
names_with_path.append(cur_names_with_path)
raise MultiJoin(pos + 1, names_with_path)
last = pathinfos[-1]
path.extend(pathinfos)
final_field = last.join_field
opts = last.to_opts
targets = last.target_fields
cur_names_with_path[1].extend(pathinfos)
names_with_path.append(cur_names_with_path)
else:
# Local non-relational field.
final_field = field
targets = (field,)
if fail_on_missing and pos + 1 != len(names):
raise FieldError(
"Cannot resolve keyword %r into field. Join on '%s'"
" not permitted." % (names[pos + 1], name)
)
break
return path, final_field, targets, names[pos + 1 :]
def setup_joins(
self,
names,
opts,
alias,
can_reuse=None,
allow_many=True,
reuse_with_filtered_relation=False,
):
"""
Compute the necessary table joins for the passage through the fields
given in 'names'. 'opts' is the Options class for the current model
(which gives the table we are starting from), 'alias' is the alias for
the table to start the joining from.
The 'can_reuse' defines the reverse foreign key joins we can reuse. It
can be None in which case all joins are reusable or a set of aliases
that can be reused. Note that non-reverse foreign keys are always
reusable when using setup_joins().
The 'reuse_with_filtered_relation' can be used to force 'can_reuse'
parameter and force the relation on the given connections.
If 'allow_many' is False, then any reverse foreign key seen will
generate a MultiJoin exception.
Return the final field involved in the joins, the target field (used
for any 'where' constraint), the final 'opts' value, the joins, the
field path traveled to generate the joins, and a transform function
that takes a field and alias and is equivalent to `field.get_col(alias)`
in the simple case but wraps field transforms if they were included in
names.
The target field is the field containing the concrete value. Final
field can be something different, for example foreign key pointing to
that value. Final field is needed for example in some value
conversions (convert 'obj' in fk__id=obj to pk val using the foreign
key field for example).
"""
joins = [alias]
# The transform can't be applied yet, as joins must be trimmed later.
# To avoid making every caller of this method look up transforms
# directly, compute transforms here and create a partial that converts
# fields to the appropriate wrapped version.
def final_transformer(field, alias):
if not self.alias_cols:
alias = None
return field.get_col(alias)
# Try resolving all the names as fields first. If there's an error,
# treat trailing names as lookups until a field can be resolved.
last_field_exception = None
for pivot in range(len(names), 0, -1):
try:
path, final_field, targets, rest = self.names_to_path(
names[:pivot],
opts,
allow_many,
fail_on_missing=True,
)
except FieldError as exc:
if pivot == 1:
# The first item cannot be a lookup, so it's safe
# to raise the field error here.
raise
else:
last_field_exception = exc
else:
# The transforms are the remaining items that couldn't be
# resolved into fields.
transforms = names[pivot:]
break
for name in transforms:
def transform(field, alias, *, name, previous):
try:
wrapped = previous(field, alias)
return self.try_transform(wrapped, name)
except FieldError:
# FieldError is raised if the transform doesn't exist.
if isinstance(final_field, Field) and last_field_exception:
raise last_field_exception
else:
raise
final_transformer = functools.partial(
transform, name=name, previous=final_transformer
)
final_transformer.has_transforms = True
# Then, add the path to the query's joins. Note that we can't trim
# joins at this stage - we will need the information about join type
# of the trimmed joins.
for join in path:
if join.filtered_relation:
filtered_relation = join.filtered_relation.clone()
table_alias = filtered_relation.alias
else:
filtered_relation = None
table_alias = None
opts = join.to_opts
if join.direct:
nullable = self.is_nullable(join.join_field)
else:
nullable = True
connection = self.join_class(
opts.db_table,
alias,
table_alias,
INNER,
join.join_field,
nullable,
filtered_relation=filtered_relation,
)
reuse = can_reuse if join.m2m or reuse_with_filtered_relation else None
alias = self.join(
connection,
reuse=reuse,
reuse_with_filtered_relation=reuse_with_filtered_relation,
)
joins.append(alias)
if filtered_relation:
filtered_relation.path = joins[:]
return JoinInfo(final_field, targets, opts, joins, path, final_transformer)
def trim_joins(self, targets, joins, path):
"""
The 'target' parameter is the final field being joined to, 'joins'
is the full list of join aliases. The 'path' contain the PathInfos
used to create the joins.
Return the final target field and table alias and the new active
joins.
Always trim any direct join if the target column is already in the
previous table. Can't trim reverse joins as it's unknown if there's
anything on the other side of the join.
"""
joins = joins[:]
for pos, info in enumerate(reversed(path)):
if len(joins) == 1 or not info.direct:
break
if info.filtered_relation:
break
join_targets = {t.column for t in info.join_field.foreign_related_fields}
cur_targets = {t.column for t in targets}
if not cur_targets.issubset(join_targets):
break
targets_dict = {
r[1].column: r[0]
for r in info.join_field.related_fields
if r[1].column in cur_targets
}
targets = tuple(targets_dict[t.column] for t in targets)
self.unref_alias(joins.pop())
return targets, joins[-1], joins
@classmethod
def _gen_cols(cls, exprs, include_external=False, resolve_refs=True):
for expr in exprs:
if isinstance(expr, Col):
yield expr
elif include_external and callable(
getattr(expr, "get_external_cols", None)
):
yield from expr.get_external_cols()
elif hasattr(expr, "get_source_expressions"):
if not resolve_refs and isinstance(expr, Ref):
continue
yield from cls._gen_cols(
expr.get_source_expressions(),
include_external=include_external,
resolve_refs=resolve_refs,
)
@classmethod
def _gen_col_aliases(cls, exprs):
yield from (expr.alias for expr in cls._gen_cols(exprs))
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
annotation = self.annotations.get(name)
if annotation is not None:
if not allow_joins:
for alias in self._gen_col_aliases([annotation]):
if isinstance(self.alias_map[alias], Join):
raise FieldError(
"Joined field references are not permitted in this query"
)
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
if name not in self.annotation_select:
raise FieldError(
"Cannot aggregate over the '%s' alias. Use annotate() "
"to promote it." % name
)
return Ref(name, self.annotation_select[name])
else:
return annotation
else:
field_list = name.split(LOOKUP_SEP)
annotation = self.annotations.get(field_list[0])
if annotation is not None:
for transform in field_list[1:]:
annotation = self.try_transform(annotation, transform)
return annotation
join_info = self.setup_joins(
field_list, self.get_meta(), self.get_initial_alias(), can_reuse=reuse
)
targets, final_alias, join_list = self.trim_joins(
join_info.targets, join_info.joins, join_info.path
)
if not allow_joins and len(join_list) > 1:
raise FieldError(
"Joined field references are not permitted in this query"
)
if len(targets) > 1:
raise FieldError(
"Referencing multicolumn fields with F() objects isn't supported"
)
# Verify that the last lookup in name is a field or a transform:
# transform_function() raises FieldError if not.
transform = join_info.transform_function(targets[0], final_alias)
if reuse is not None:
reuse.update(join_list)
return transform
def split_exclude(self, filter_expr, can_reuse, names_with_path):
"""
When doing an exclude against any kind of N-to-many relation, we need
to use a subquery. This method constructs the nested query, given the
original exclude filter (filter_expr) and the portion up to the first
N-to-many relation field.
For example, if the origin filter is ~Q(child__name='foo'), filter_expr
is ('child__name', 'foo') and can_reuse is a set of joins usable for
filters in the original query.
We will turn this into equivalent of:
WHERE NOT EXISTS(
SELECT 1
FROM child
WHERE name = 'foo' AND child.parent_id = parent.id
LIMIT 1
)
"""
# Generate the inner query.
query = self.__class__(self.model)
query._filtered_relations = self._filtered_relations
filter_lhs, filter_rhs = filter_expr
if isinstance(filter_rhs, OuterRef):
filter_rhs = OuterRef(filter_rhs)
elif isinstance(filter_rhs, F):
filter_rhs = OuterRef(filter_rhs.name)
query.add_filter(filter_lhs, filter_rhs)
query.clear_ordering(force=True)
# Try to have as simple as possible subquery -> trim leading joins from
# the subquery.
trimmed_prefix, contains_louter = query.trim_start(names_with_path)
col = query.select[0]
select_field = col.target
alias = col.alias
if alias in can_reuse:
pk = select_field.model._meta.pk
# Need to add a restriction so that outer query's filters are in effect for
# the subquery, too.
query.bump_prefix(self)
lookup_class = select_field.get_lookup("exact")
# Note that the query.select[0].alias is different from alias
# due to bump_prefix above.
lookup = lookup_class(pk.get_col(query.select[0].alias), pk.get_col(alias))
query.where.add(lookup, AND)
query.external_aliases[alias] = True
lookup_class = select_field.get_lookup("exact")
lookup = lookup_class(col, ResolvedOuterRef(trimmed_prefix))
query.where.add(lookup, AND)
condition, needed_inner = self.build_filter(Exists(query))
if contains_louter:
or_null_condition, _ = self.build_filter(
("%s__isnull" % trimmed_prefix, True),
current_negated=True,
branch_negated=True,
can_reuse=can_reuse,
)
condition.add(or_null_condition, OR)
# Note that the end result will be:
# (outercol NOT IN innerq AND outercol IS NOT NULL) OR outercol IS NULL.
# This might look crazy but due to how IN works, this seems to be
# correct. If the IS NOT NULL check is removed then outercol NOT
# IN will return UNKNOWN. If the IS NULL check is removed, then if
# outercol IS NULL we will not match the row.
return condition, needed_inner
def set_empty(self):
self.where.add(NothingNode(), AND)
for query in self.combined_queries:
query.set_empty()
def is_empty(self):
return any(isinstance(c, NothingNode) for c in self.where.children)
def set_limits(self, low=None, high=None):
"""
Adjust the limits on the rows retrieved. Use low/high to set these,
as it makes it more Pythonic to read and write. When the SQL query is
created, convert them to the appropriate offset and limit values.
Apply any limits passed in here to the existing constraints. Add low
to the current low value and clamp both to any existing high value.
"""
if high is not None:
if self.high_mark is not None:
self.high_mark = min(self.high_mark, self.low_mark + high)
else:
self.high_mark = self.low_mark + high
if low is not None:
if self.high_mark is not None:
self.low_mark = min(self.high_mark, self.low_mark + low)
else:
self.low_mark = self.low_mark + low
if self.low_mark == self.high_mark:
self.set_empty()
def clear_limits(self):
"""Clear any existing limits."""
self.low_mark, self.high_mark = 0, None
@property
def is_sliced(self):
return self.low_mark != 0 or self.high_mark is not None
def has_limit_one(self):
return self.high_mark is not None and (self.high_mark - self.low_mark) == 1
def can_filter(self):
"""
Return True if adding filters to this instance is still possible.
Typically, this means no limits or offsets have been put on the results.
"""
return not self.is_sliced
def clear_select_clause(self):
"""Remove all fields from SELECT clause."""
self.select = ()
self.default_cols = False
self.select_related = False
self.set_extra_mask(())
self.set_annotation_mask(())
def clear_select_fields(self):
"""
Clear the list of fields to select (but not extra_select columns).
Some queryset types completely replace any existing list of select
columns.
"""
self.select = ()
self.values_select = ()
def add_select_col(self, col, name):
self.select += (col,)
self.values_select += (name,)
def set_select(self, cols):
self.default_cols = False
self.select = tuple(cols)
def add_distinct_fields(self, *field_names):
"""
Add and resolve the given fields to the query's "distinct on" clause.
"""
self.distinct_fields = field_names
self.distinct = True
def add_fields(self, field_names, allow_m2m=True):
"""
Add the given (model) fields to the select set. Add the field names in
the order specified.
"""
alias = self.get_initial_alias()
opts = self.get_meta()
try:
cols = []
for name in field_names:
# Join promotion note - we must not remove any rows here, so
# if there is no existing joins, use outer join.
join_info = self.setup_joins(
name.split(LOOKUP_SEP), opts, alias, allow_many=allow_m2m
)
targets, final_alias, joins = self.trim_joins(
join_info.targets,
join_info.joins,
join_info.path,
)
for target in targets:
cols.append(join_info.transform_function(target, final_alias))
if cols:
self.set_select(cols)
except MultiJoin:
raise FieldError("Invalid field name: '%s'" % name)
except FieldError:
if LOOKUP_SEP in name:
# For lookups spanning over relationships, show the error
# from the model on which the lookup failed.
raise
elif name in self.annotations:
raise FieldError(
"Cannot select the '%s' alias. Use annotate() to promote "
"it." % name
)
else:
names = sorted(
[
*get_field_names_from_opts(opts),
*self.extra,
*self.annotation_select,
*self._filtered_relations,
]
)
raise FieldError(
"Cannot resolve keyword %r into field. "
"Choices are: %s" % (name, ", ".join(names))
)
def add_ordering(self, *ordering):
"""
Add items from the 'ordering' sequence to the query's "order by"
clause. These items are either field names (not column names) --
possibly with a direction prefix ('-' or '?') -- or OrderBy
expressions.
If 'ordering' is empty, clear all ordering from the query.
"""
errors = []
for item in ordering:
if isinstance(item, str):
if item == "?":
continue
if item.startswith("-"):
item = item[1:]
if item in self.annotations:
continue
if self.extra and item in self.extra:
continue
# names_to_path() validates the lookup. A descriptive
# FieldError will be raise if it's not.
self.names_to_path(item.split(LOOKUP_SEP), self.model._meta)
elif not hasattr(item, "resolve_expression"):
errors.append(item)
if getattr(item, "contains_aggregate", False):
raise FieldError(
"Using an aggregate in order_by() without also including "
"it in annotate() is not allowed: %s" % item
)
if errors:
raise FieldError("Invalid order_by arguments: %s" % errors)
if ordering:
self.order_by += ordering
else:
self.default_ordering = False
def clear_ordering(self, force=False, clear_default=True):
"""
Remove any ordering settings if the current query allows it without
side effects, set 'force' to True to clear the ordering regardless.
If 'clear_default' is True, there will be no ordering in the resulting
query (not even the model's default).
"""
if not force and (
self.is_sliced or self.distinct_fields or self.select_for_update
):
return
self.order_by = ()
self.extra_order_by = ()
if clear_default:
self.default_ordering = False
def set_group_by(self, allow_aliases=True):
"""
Expand the GROUP BY clause required by the query.
This will usually be the set of all non-aggregate fields in the
return data. If the database backend supports grouping by the
primary key, and the query would be equivalent, the optimization
will be made automatically.
"""
if allow_aliases and self.values_select:
# If grouping by aliases is allowed assign selected value aliases
# by moving them to annotations.
group_by_annotations = {}
values_select = {}
for alias, expr in zip(self.values_select, self.select):
if isinstance(expr, Col):
values_select[alias] = expr
else:
group_by_annotations[alias] = expr
self.annotations = {**group_by_annotations, **self.annotations}
self.append_annotation_mask(group_by_annotations)
self.select = tuple(values_select.values())
self.values_select = tuple(values_select)
group_by = list(self.select)
for alias, annotation in self.annotation_select.items():
if not (group_by_cols := annotation.get_group_by_cols()):
continue
if allow_aliases and not annotation.contains_aggregate:
group_by.append(Ref(alias, annotation))
else:
group_by.extend(group_by_cols)
self.group_by = tuple(group_by)
def add_select_related(self, fields):
"""
Set up the select_related data structure so that we only select
certain related models (as opposed to all models, when
self.select_related=True).
"""
if isinstance(self.select_related, bool):
field_dict = {}
else:
field_dict = self.select_related
for field in fields:
d = field_dict
for part in field.split(LOOKUP_SEP):
d = d.setdefault(part, {})
self.select_related = field_dict
def add_extra(self, select, select_params, where, params, tables, order_by):
"""
Add data to the various extra_* attributes for user-created additions
to the query.
"""
if select:
# We need to pair any placeholder markers in the 'select'
# dictionary with their parameters in 'select_params' so that
# subsequent updates to the select dictionary also adjust the
# parameters appropriately.
select_pairs = {}
if select_params:
param_iter = iter(select_params)
else:
param_iter = iter([])
for name, entry in select.items():
self.check_alias(name)
entry = str(entry)
entry_params = []
pos = entry.find("%s")
while pos != -1:
if pos == 0 or entry[pos - 1] != "%":
entry_params.append(next(param_iter))
pos = entry.find("%s", pos + 2)
select_pairs[name] = (entry, entry_params)
self.extra.update(select_pairs)
if where or params:
self.where.add(ExtraWhere(where, params), AND)
if tables:
self.extra_tables += tuple(tables)
if order_by:
self.extra_order_by = order_by
def clear_deferred_loading(self):
"""Remove any fields from the deferred loading set."""
self.deferred_loading = (frozenset(), True)
def add_deferred_loading(self, field_names):
"""
Add the given list of model field names to the set of fields to
exclude from loading from the database when automatic column selection
is done. Add the new field names to any existing field names that
are deferred (or removed from any existing field names that are marked
as the only ones for immediate loading).
"""
# Fields on related models are stored in the literal double-underscore
# format, so that we can use a set datastructure. We do the foo__bar
# splitting and handling when computing the SQL column names (as part of
# get_columns()).
existing, defer = self.deferred_loading
if defer:
# Add to existing deferred names.
self.deferred_loading = existing.union(field_names), True
else:
# Remove names from the set of any existing "immediate load" names.
if new_existing := existing.difference(field_names):
self.deferred_loading = new_existing, False
else:
self.clear_deferred_loading()
if new_only := set(field_names).difference(existing):
self.deferred_loading = new_only, True
def add_immediate_loading(self, field_names):
"""
Add the given list of model field names to the set of fields to
retrieve when the SQL is executed ("immediate loading" fields). The
field names replace any existing immediate loading field names. If
there are field names already specified for deferred loading, remove
those names from the new field_names before storing the new names
for immediate loading. (That is, immediate loading overrides any
existing immediate values, but respects existing deferrals.)
"""
existing, defer = self.deferred_loading
field_names = set(field_names)
if "pk" in field_names:
field_names.remove("pk")
field_names.add(self.get_meta().pk.name)
if defer:
# Remove any existing deferred names from the current set before
# setting the new names.
self.deferred_loading = field_names.difference(existing), False
else:
# Replace any existing "immediate load" field names.
self.deferred_loading = frozenset(field_names), False
def set_annotation_mask(self, names):
"""Set the mask of annotations that will be returned by the SELECT."""
if names is None:
self.annotation_select_mask = None
else:
self.annotation_select_mask = set(names)
self._annotation_select_cache = None
def append_annotation_mask(self, names):
if self.annotation_select_mask is not None:
self.set_annotation_mask(self.annotation_select_mask.union(names))
def set_extra_mask(self, names):
"""
Set the mask of extra select items that will be returned by SELECT.
Don't remove them from the Query since they might be used later.
"""
if names is None:
self.extra_select_mask = None
else:
self.extra_select_mask = set(names)
self._extra_select_cache = None
def set_values(self, fields):
self.select_related = False
self.clear_deferred_loading()
self.clear_select_fields()
self.has_select_fields = True
if fields:
field_names = []
extra_names = []
annotation_names = []
if not self.extra and not self.annotations:
# Shortcut - if there are no extra or annotations, then
# the values() clause must be just field names.
field_names = list(fields)
else:
self.default_cols = False
for f in fields:
if f in self.extra_select:
extra_names.append(f)
elif f in self.annotation_select:
annotation_names.append(f)
else:
field_names.append(f)
self.set_extra_mask(extra_names)
self.set_annotation_mask(annotation_names)
selected = frozenset(field_names + extra_names + annotation_names)
else:
field_names = [f.attname for f in self.model._meta.concrete_fields]
selected = frozenset(field_names)
# Selected annotations must be known before setting the GROUP BY
# clause.
if self.group_by is True:
self.add_fields(
(f.attname for f in self.model._meta.concrete_fields), False
)
# Disable GROUP BY aliases to avoid orphaning references to the
# SELECT clause which is about to be cleared.
self.set_group_by(allow_aliases=False)
self.clear_select_fields()
elif self.group_by:
# Resolve GROUP BY annotation references if they are not part of
# the selected fields anymore.
group_by = []
for expr in self.group_by:
if isinstance(expr, Ref) and expr.refs not in selected:
expr = self.annotations[expr.refs]
group_by.append(expr)
self.group_by = tuple(group_by)
self.values_select = tuple(field_names)
self.add_fields(field_names, True)
@property
def annotation_select(self):
"""
Return the dictionary of aggregate columns that are not masked and
should be used in the SELECT clause. Cache this result for performance.
"""
if self._annotation_select_cache is not None:
return self._annotation_select_cache
elif not self.annotations:
return {}
elif self.annotation_select_mask is not None:
self._annotation_select_cache = {
k: v
for k, v in self.annotations.items()
if k in self.annotation_select_mask
}
return self._annotation_select_cache
else:
return self.annotations
@property
def extra_select(self):
if self._extra_select_cache is not None:
return self._extra_select_cache
if not self.extra:
return {}
elif self.extra_select_mask is not None:
self._extra_select_cache = {
k: v for k, v in self.extra.items() if k in self.extra_select_mask
}
return self._extra_select_cache
else:
return self.extra
def trim_start(self, names_with_path):
"""
Trim joins from the start of the join path. The candidates for trim
are the PathInfos in names_with_path structure that are m2m joins.
Also set the select column so the start matches the join.
This method is meant to be used for generating the subquery joins &
cols in split_exclude().
Return a lookup usable for doing outerq.filter(lookup=self) and a
boolean indicating if the joins in the prefix contain a LEFT OUTER join.
_"""
all_paths = []
for _, paths in names_with_path:
all_paths.extend(paths)
contains_louter = False
# Trim and operate only on tables that were generated for
# the lookup part of the query. That is, avoid trimming
# joins generated for F() expressions.
lookup_tables = [
t for t in self.alias_map if t in self._lookup_joins or t == self.base_table
]
for trimmed_paths, path in enumerate(all_paths):
if path.m2m:
break
if self.alias_map[lookup_tables[trimmed_paths + 1]].join_type == LOUTER:
contains_louter = True
alias = lookup_tables[trimmed_paths]
self.unref_alias(alias)
# The path.join_field is a Rel, lets get the other side's field
join_field = path.join_field.field
# Build the filter prefix.
paths_in_prefix = trimmed_paths
trimmed_prefix = []
for name, path in names_with_path:
if paths_in_prefix - len(path) < 0:
break
trimmed_prefix.append(name)
paths_in_prefix -= len(path)
trimmed_prefix.append(join_field.foreign_related_fields[0].name)
trimmed_prefix = LOOKUP_SEP.join(trimmed_prefix)
# Lets still see if we can trim the first join from the inner query
# (that is, self). We can't do this for:
# - LEFT JOINs because we would miss those rows that have nothing on
# the outer side,
# - INNER JOINs from filtered relations because we would miss their
# filters.
first_join = self.alias_map[lookup_tables[trimmed_paths + 1]]
if first_join.join_type != LOUTER and not first_join.filtered_relation:
select_fields = [r[0] for r in join_field.related_fields]
select_alias = lookup_tables[trimmed_paths + 1]
self.unref_alias(lookup_tables[trimmed_paths])
extra_restriction = join_field.get_extra_restriction(
None, lookup_tables[trimmed_paths + 1]
)
if extra_restriction:
self.where.add(extra_restriction, AND)
else:
# TODO: It might be possible to trim more joins from the start of the
# inner query if it happens to have a longer join chain containing the
# values in select_fields. Lets punt this one for now.
select_fields = [r[1] for r in join_field.related_fields]
select_alias = lookup_tables[trimmed_paths]
# The found starting point is likely a join_class instead of a
# base_table_class reference. But the first entry in the query's FROM
# clause must not be a JOIN.
for table in self.alias_map:
if self.alias_refcount[table] > 0:
self.alias_map[table] = self.base_table_class(
self.alias_map[table].table_name,
table,
)
break
self.set_select([f.get_col(select_alias) for f in select_fields])
return trimmed_prefix, contains_louter
def is_nullable(self, field):
"""
Check if the given field should be treated as nullable.
Some backends treat '' as null and Django treats such fields as
nullable for those backends. In such situations field.null can be
False even if we should treat the field as nullable.
"""
# We need to use DEFAULT_DB_ALIAS here, as QuerySet does not have
# (nor should it have) knowledge of which connection is going to be
# used. The proper fix would be to defer all decisions where
# is_nullable() is needed to the compiler stage, but that is not easy
# to do currently.
return field.null or (
field.empty_strings_allowed
and connections[DEFAULT_DB_ALIAS].features.interprets_empty_strings_as_nulls
)
def get_order_dir(field, default="ASC"):
"""
Return the field name and direction for an order specification. For
example, '-foo' is returned as ('foo', 'DESC').
The 'default' param is used to indicate which way no prefix (or a '+'
prefix) should sort. The '-' prefix always sorts the opposite way.
"""
dirn = ORDER_DIR[default]
if field[0] == "-":
return field[1:], dirn[1]
return field, dirn[0]
class JoinPromoter:
"""
A class to abstract away join promotion problems for complex filter
conditions.
"""
def __init__(self, connector, num_children, negated):
self.connector = connector
self.negated = negated
if self.negated:
if connector == AND:
self.effective_connector = OR
else:
self.effective_connector = AND
else:
self.effective_connector = self.connector
self.num_children = num_children
# Maps of table alias to how many times it is seen as required for
# inner and/or outer joins.
self.votes = Counter()
def __repr__(self):
return (
f"{self.__class__.__qualname__}(connector={self.connector!r}, "
f"num_children={self.num_children!r}, negated={self.negated!r})"
)
def add_votes(self, votes):
"""
Add single vote per item to self.votes. Parameter can be any
iterable.
"""
self.votes.update(votes)
def update_join_types(self, query):
"""
Change join types so that the generated query is as efficient as
possible, but still correct. So, change as many joins as possible
to INNER, but don't make OUTER joins INNER if that could remove
results from the query.
"""
to_promote = set()
to_demote = set()
# The effective_connector is used so that NOT (a AND b) is treated
# similarly to (a OR b) for join promotion.
for table, votes in self.votes.items():
# We must use outer joins in OR case when the join isn't contained
# in all of the joins. Otherwise the INNER JOIN itself could remove
# valid results. Consider the case where a model with rel_a and
# rel_b relations is queried with rel_a__col=1 | rel_b__col=2. Now,
# if rel_a join doesn't produce any results is null (for example
# reverse foreign key or null value in direct foreign key), and
# there is a matching row in rel_b with col=2, then an INNER join
# to rel_a would remove a valid match from the query. So, we need
# to promote any existing INNER to LOUTER (it is possible this
# promotion in turn will be demoted later on).
if self.effective_connector == OR and votes < self.num_children:
to_promote.add(table)
# If connector is AND and there is a filter that can match only
# when there is a joinable row, then use INNER. For example, in
# rel_a__col=1 & rel_b__col=2, if either of the rels produce NULL
# as join output, then the col=1 or col=2 can't match (as
# NULL=anything is always false).
# For the OR case, if all children voted for a join to be inner,
# then we can use INNER for the join. For example:
# (rel_a__col__icontains=Alex | rel_a__col__icontains=Russell)
# then if rel_a doesn't produce any rows, the whole condition
# can't match. Hence we can safely use INNER join.
if self.effective_connector == AND or (
self.effective_connector == OR and votes == self.num_children
):
to_demote.add(table)
# Finally, what happens in cases where we have:
# (rel_a__col=1|rel_b__col=2) & rel_a__col__gte=0
# Now, we first generate the OR clause, and promote joins for it
# in the first if branch above. Both rel_a and rel_b are promoted
# to LOUTER joins. After that we do the AND case. The OR case
# voted no inner joins but the rel_a__col__gte=0 votes inner join
# for rel_a. We demote it back to INNER join (in AND case a single
# vote is enough). The demotion is OK, if rel_a doesn't produce
# rows, then the rel_a__col__gte=0 clause can't be true, and thus
# the whole clause must be false. So, it is safe to use INNER
# join.
# Note that in this example we could just as well have the __gte
# clause and the OR clause swapped. Or we could replace the __gte
# clause with an OR clause containing rel_a__col=1|rel_a__col=2,
# and again we could safely demote to INNER.
query.promote_joins(to_promote)
query.demote_joins(to_demote)
return to_demote
|
castiel248/Convert
|
Lib/site-packages/django/db/models/sql/query.py
|
Python
|
mit
| 114,554 |
"""
Query subclasses which provide extra functionality beyond simple data retrieval.
"""
from django.core.exceptions import FieldError
from django.db.models.sql.constants import CURSOR, GET_ITERATOR_CHUNK_SIZE, NO_RESULTS
from django.db.models.sql.query import Query
__all__ = ["DeleteQuery", "UpdateQuery", "InsertQuery", "AggregateQuery"]
class DeleteQuery(Query):
"""A DELETE SQL query."""
compiler = "SQLDeleteCompiler"
def do_query(self, table, where, using):
self.alias_map = {table: self.alias_map[table]}
self.where = where
cursor = self.get_compiler(using).execute_sql(CURSOR)
if cursor:
with cursor:
return cursor.rowcount
return 0
def delete_batch(self, pk_list, using):
"""
Set up and execute delete queries for all the objects in pk_list.
More than one physical query may be executed if there are a
lot of values in pk_list.
"""
# number of objects deleted
num_deleted = 0
field = self.get_meta().pk
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
self.clear_where()
self.add_filter(
f"{field.attname}__in",
pk_list[offset : offset + GET_ITERATOR_CHUNK_SIZE],
)
num_deleted += self.do_query(
self.get_meta().db_table, self.where, using=using
)
return num_deleted
class UpdateQuery(Query):
"""An UPDATE SQL query."""
compiler = "SQLUpdateCompiler"
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._setup_query()
def _setup_query(self):
"""
Run on initialization and at the end of chaining. Any attributes that
would normally be set in __init__() should go here instead.
"""
self.values = []
self.related_ids = None
self.related_updates = {}
def clone(self):
obj = super().clone()
obj.related_updates = self.related_updates.copy()
return obj
def update_batch(self, pk_list, values, using):
self.add_update_values(values)
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
self.clear_where()
self.add_filter(
"pk__in", pk_list[offset : offset + GET_ITERATOR_CHUNK_SIZE]
)
self.get_compiler(using).execute_sql(NO_RESULTS)
def add_update_values(self, values):
"""
Convert a dictionary of field name to value mappings into an update
query. This is the entry point for the public update() method on
querysets.
"""
values_seq = []
for name, val in values.items():
field = self.get_meta().get_field(name)
direct = (
not (field.auto_created and not field.concrete) or not field.concrete
)
model = field.model._meta.concrete_model
if not direct or (field.is_relation and field.many_to_many):
raise FieldError(
"Cannot update model field %r (only non-relations and "
"foreign keys permitted)." % field
)
if model is not self.get_meta().concrete_model:
self.add_related_update(model, field, val)
continue
values_seq.append((field, model, val))
return self.add_update_fields(values_seq)
def add_update_fields(self, values_seq):
"""
Append a sequence of (field, model, value) triples to the internal list
that will be used to generate the UPDATE query. Might be more usefully
called add_update_targets() to hint at the extra information here.
"""
for field, model, val in values_seq:
if hasattr(val, "resolve_expression"):
# Resolve expressions here so that annotations are no longer needed
val = val.resolve_expression(self, allow_joins=False, for_save=True)
self.values.append((field, model, val))
def add_related_update(self, model, field, value):
"""
Add (name, value) to an update query for an ancestor model.
Update are coalesced so that only one update query per ancestor is run.
"""
self.related_updates.setdefault(model, []).append((field, None, value))
def get_related_updates(self):
"""
Return a list of query objects: one for each update required to an
ancestor model. Each query will have the same filtering conditions as
the current query but will only update a single table.
"""
if not self.related_updates:
return []
result = []
for model, values in self.related_updates.items():
query = UpdateQuery(model)
query.values = values
if self.related_ids is not None:
query.add_filter("pk__in", self.related_ids[model])
result.append(query)
return result
class InsertQuery(Query):
compiler = "SQLInsertCompiler"
def __init__(
self, *args, on_conflict=None, update_fields=None, unique_fields=None, **kwargs
):
super().__init__(*args, **kwargs)
self.fields = []
self.objs = []
self.on_conflict = on_conflict
self.update_fields = update_fields or []
self.unique_fields = unique_fields or []
def insert_values(self, fields, objs, raw=False):
self.fields = fields
self.objs = objs
self.raw = raw
class AggregateQuery(Query):
"""
Take another query as a parameter to the FROM clause and only select the
elements in the provided list.
"""
compiler = "SQLAggregateCompiler"
def __init__(self, model, inner_query):
self.inner_query = inner_query
super().__init__(model)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/sql/subqueries.py
|
Python
|
mit
| 5,935 |
"""
Code to manage the creation and SQL rendering of 'where' constraints.
"""
import operator
from functools import reduce
from django.core.exceptions import EmptyResultSet, FullResultSet
from django.db.models.expressions import Case, When
from django.db.models.lookups import Exact
from django.utils import tree
from django.utils.functional import cached_property
# Connection types
AND = "AND"
OR = "OR"
XOR = "XOR"
class WhereNode(tree.Node):
"""
An SQL WHERE clause.
The class is tied to the Query class that created it (in order to create
the correct SQL).
A child is usually an expression producing boolean values. Most likely the
expression is a Lookup instance.
However, a child could also be any class with as_sql() and either
relabeled_clone() method or relabel_aliases() and clone() methods and
contains_aggregate attribute.
"""
default = AND
resolved = False
conditional = True
def split_having_qualify(self, negated=False, must_group_by=False):
"""
Return three possibly None nodes: one for those parts of self that
should be included in the WHERE clause, one for those parts of self
that must be included in the HAVING clause, and one for those parts
that refer to window functions.
"""
if not self.contains_aggregate and not self.contains_over_clause:
return self, None, None
in_negated = negated ^ self.negated
# Whether or not children must be connected in the same filtering
# clause (WHERE > HAVING > QUALIFY) to maintain logical semantic.
must_remain_connected = (
(in_negated and self.connector == AND)
or (not in_negated and self.connector == OR)
or self.connector == XOR
)
if (
must_remain_connected
and self.contains_aggregate
and not self.contains_over_clause
):
# It's must cheaper to short-circuit and stash everything in the
# HAVING clause than split children if possible.
return None, self, None
where_parts = []
having_parts = []
qualify_parts = []
for c in self.children:
if hasattr(c, "split_having_qualify"):
where_part, having_part, qualify_part = c.split_having_qualify(
in_negated, must_group_by
)
if where_part is not None:
where_parts.append(where_part)
if having_part is not None:
having_parts.append(having_part)
if qualify_part is not None:
qualify_parts.append(qualify_part)
elif c.contains_over_clause:
qualify_parts.append(c)
elif c.contains_aggregate:
having_parts.append(c)
else:
where_parts.append(c)
if must_remain_connected and qualify_parts:
# Disjunctive heterogeneous predicates can be pushed down to
# qualify as long as no conditional aggregation is involved.
if not where_parts or (where_parts and not must_group_by):
return None, None, self
elif where_parts:
# In theory this should only be enforced when dealing with
# where_parts containing predicates against multi-valued
# relationships that could affect aggregation results but this
# is complex to infer properly.
raise NotImplementedError(
"Heterogeneous disjunctive predicates against window functions are "
"not implemented when performing conditional aggregation."
)
where_node = (
self.create(where_parts, self.connector, self.negated)
if where_parts
else None
)
having_node = (
self.create(having_parts, self.connector, self.negated)
if having_parts
else None
)
qualify_node = (
self.create(qualify_parts, self.connector, self.negated)
if qualify_parts
else None
)
return where_node, having_node, qualify_node
def as_sql(self, compiler, connection):
"""
Return the SQL version of the where clause and the value to be
substituted in. Return '', [] if this node matches everything,
None, [] if this node is empty, and raise EmptyResultSet if this
node can't match anything.
"""
result = []
result_params = []
if self.connector == AND:
full_needed, empty_needed = len(self.children), 1
else:
full_needed, empty_needed = 1, len(self.children)
if self.connector == XOR and not connection.features.supports_logical_xor:
# Convert if the database doesn't support XOR:
# a XOR b XOR c XOR ...
# to:
# (a OR b OR c OR ...) AND (a + b + c + ...) == 1
lhs = self.__class__(self.children, OR)
rhs_sum = reduce(
operator.add,
(Case(When(c, then=1), default=0) for c in self.children),
)
rhs = Exact(1, rhs_sum)
return self.__class__([lhs, rhs], AND, self.negated).as_sql(
compiler, connection
)
for child in self.children:
try:
sql, params = compiler.compile(child)
except EmptyResultSet:
empty_needed -= 1
except FullResultSet:
full_needed -= 1
else:
if sql:
result.append(sql)
result_params.extend(params)
else:
full_needed -= 1
# Check if this node matches nothing or everything.
# First check the amount of full nodes and empty nodes
# to make this node empty/full.
# Now, check if this node is full/empty using the
# counts.
if empty_needed == 0:
if self.negated:
raise FullResultSet
else:
raise EmptyResultSet
if full_needed == 0:
if self.negated:
raise EmptyResultSet
else:
raise FullResultSet
conn = " %s " % self.connector
sql_string = conn.join(result)
if not sql_string:
raise FullResultSet
if self.negated:
# Some backends (Oracle at least) need parentheses around the inner
# SQL in the negated case, even if the inner SQL contains just a
# single expression.
sql_string = "NOT (%s)" % sql_string
elif len(result) > 1 or self.resolved:
sql_string = "(%s)" % sql_string
return sql_string, result_params
def get_group_by_cols(self):
cols = []
for child in self.children:
cols.extend(child.get_group_by_cols())
return cols
def get_source_expressions(self):
return self.children[:]
def set_source_expressions(self, children):
assert len(children) == len(self.children)
self.children = children
def relabel_aliases(self, change_map):
"""
Relabel the alias values of any children. 'change_map' is a dictionary
mapping old (current) alias values to the new values.
"""
for pos, child in enumerate(self.children):
if hasattr(child, "relabel_aliases"):
# For example another WhereNode
child.relabel_aliases(change_map)
elif hasattr(child, "relabeled_clone"):
self.children[pos] = child.relabeled_clone(change_map)
def clone(self):
clone = self.create(connector=self.connector, negated=self.negated)
for child in self.children:
if hasattr(child, "clone"):
child = child.clone()
clone.children.append(child)
return clone
def relabeled_clone(self, change_map):
clone = self.clone()
clone.relabel_aliases(change_map)
return clone
def replace_expressions(self, replacements):
if replacement := replacements.get(self):
return replacement
clone = self.create(connector=self.connector, negated=self.negated)
for child in self.children:
clone.children.append(child.replace_expressions(replacements))
return clone
def get_refs(self):
refs = set()
for child in self.children:
refs |= child.get_refs()
return refs
@classmethod
def _contains_aggregate(cls, obj):
if isinstance(obj, tree.Node):
return any(cls._contains_aggregate(c) for c in obj.children)
return obj.contains_aggregate
@cached_property
def contains_aggregate(self):
return self._contains_aggregate(self)
@classmethod
def _contains_over_clause(cls, obj):
if isinstance(obj, tree.Node):
return any(cls._contains_over_clause(c) for c in obj.children)
return obj.contains_over_clause
@cached_property
def contains_over_clause(self):
return self._contains_over_clause(self)
@property
def is_summary(self):
return any(child.is_summary for child in self.children)
@staticmethod
def _resolve_leaf(expr, query, *args, **kwargs):
if hasattr(expr, "resolve_expression"):
expr = expr.resolve_expression(query, *args, **kwargs)
return expr
@classmethod
def _resolve_node(cls, node, query, *args, **kwargs):
if hasattr(node, "children"):
for child in node.children:
cls._resolve_node(child, query, *args, **kwargs)
if hasattr(node, "lhs"):
node.lhs = cls._resolve_leaf(node.lhs, query, *args, **kwargs)
if hasattr(node, "rhs"):
node.rhs = cls._resolve_leaf(node.rhs, query, *args, **kwargs)
def resolve_expression(self, *args, **kwargs):
clone = self.clone()
clone._resolve_node(clone, *args, **kwargs)
clone.resolved = True
return clone
@cached_property
def output_field(self):
from django.db.models import BooleanField
return BooleanField()
@property
def _output_field_or_none(self):
return self.output_field
def select_format(self, compiler, sql, params):
# Wrap filters with a CASE WHEN expression if a database backend
# (e.g. Oracle) doesn't support boolean expression in SELECT or GROUP
# BY list.
if not compiler.connection.features.supports_boolean_expr_in_select_clause:
sql = f"CASE WHEN {sql} THEN 1 ELSE 0 END"
return sql, params
def get_db_converters(self, connection):
return self.output_field.get_db_converters(connection)
def get_lookup(self, lookup):
return self.output_field.get_lookup(lookup)
def leaves(self):
for child in self.children:
if isinstance(child, WhereNode):
yield from child.leaves()
else:
yield child
class NothingNode:
"""A node that matches nothing."""
contains_aggregate = False
contains_over_clause = False
def as_sql(self, compiler=None, connection=None):
raise EmptyResultSet
class ExtraWhere:
# The contents are a black box - assume no aggregates or windows are used.
contains_aggregate = False
contains_over_clause = False
def __init__(self, sqls, params):
self.sqls = sqls
self.params = params
def as_sql(self, compiler=None, connection=None):
sqls = ["(%s)" % sql for sql in self.sqls]
return " AND ".join(sqls), list(self.params or ())
class SubqueryConstraint:
# Even if aggregates or windows would be used in a subquery,
# the outer query isn't interested about those.
contains_aggregate = False
contains_over_clause = False
def __init__(self, alias, columns, targets, query_object):
self.alias = alias
self.columns = columns
self.targets = targets
query_object.clear_ordering(clear_default=True)
self.query_object = query_object
def as_sql(self, compiler, connection):
query = self.query_object
query.set_values(self.targets)
query_compiler = query.get_compiler(connection=connection)
return query_compiler.as_subquery_condition(self.alias, self.columns, compiler)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/sql/where.py
|
Python
|
mit
| 12,710 |
import functools
from collections import namedtuple
def make_model_tuple(model):
"""
Take a model or a string of the form "app_label.ModelName" and return a
corresponding ("app_label", "modelname") tuple. If a tuple is passed in,
assume it's a valid model tuple already and return it unchanged.
"""
try:
if isinstance(model, tuple):
model_tuple = model
elif isinstance(model, str):
app_label, model_name = model.split(".")
model_tuple = app_label, model_name.lower()
else:
model_tuple = model._meta.app_label, model._meta.model_name
assert len(model_tuple) == 2
return model_tuple
except (ValueError, AssertionError):
raise ValueError(
"Invalid model reference '%s'. String model references "
"must be of the form 'app_label.ModelName'." % model
)
def resolve_callables(mapping):
"""
Generate key/value pairs for the given mapping where the values are
evaluated if they're callable.
"""
for k, v in mapping.items():
yield k, v() if callable(v) else v
def unpickle_named_row(names, values):
return create_namedtuple_class(*names)(*values)
@functools.lru_cache
def create_namedtuple_class(*names):
# Cache type() with @lru_cache since it's too slow to be called for every
# QuerySet evaluation.
def __reduce__(self):
return unpickle_named_row, (names, tuple(self))
return type(
"Row",
(namedtuple("Row", names),),
{"__reduce__": __reduce__, "__slots__": ()},
)
class AltersData:
"""
Make subclasses preserve the alters_data attribute on overridden methods.
"""
def __init_subclass__(cls, **kwargs):
for fn_name, fn in vars(cls).items():
if callable(fn) and not hasattr(fn, "alters_data"):
for base in cls.__bases__:
if base_fn := getattr(base, fn_name, None):
if hasattr(base_fn, "alters_data"):
fn.alters_data = base_fn.alters_data
break
super().__init_subclass__(**kwargs)
|
castiel248/Convert
|
Lib/site-packages/django/db/models/utils.py
|
Python
|
mit
| 2,182 |
from contextlib import ContextDecorator, contextmanager
from django.db import (
DEFAULT_DB_ALIAS,
DatabaseError,
Error,
ProgrammingError,
connections,
)
class TransactionManagementError(ProgrammingError):
"""Transaction management is used improperly."""
pass
def get_connection(using=None):
"""
Get a database connection by name, or the default database connection
if no name is provided. This is a private API.
"""
if using is None:
using = DEFAULT_DB_ALIAS
return connections[using]
def get_autocommit(using=None):
"""Get the autocommit status of the connection."""
return get_connection(using).get_autocommit()
def set_autocommit(autocommit, using=None):
"""Set the autocommit status of the connection."""
return get_connection(using).set_autocommit(autocommit)
def commit(using=None):
"""Commit a transaction."""
get_connection(using).commit()
def rollback(using=None):
"""Roll back a transaction."""
get_connection(using).rollback()
def savepoint(using=None):
"""
Create a savepoint (if supported and required by the backend) inside the
current transaction. Return an identifier for the savepoint that will be
used for the subsequent rollback or commit.
"""
return get_connection(using).savepoint()
def savepoint_rollback(sid, using=None):
"""
Roll back the most recent savepoint (if one exists). Do nothing if
savepoints are not supported.
"""
get_connection(using).savepoint_rollback(sid)
def savepoint_commit(sid, using=None):
"""
Commit the most recent savepoint (if one exists). Do nothing if
savepoints are not supported.
"""
get_connection(using).savepoint_commit(sid)
def clean_savepoints(using=None):
"""
Reset the counter used to generate unique savepoint ids in this thread.
"""
get_connection(using).clean_savepoints()
def get_rollback(using=None):
"""Get the "needs rollback" flag -- for *advanced use* only."""
return get_connection(using).get_rollback()
def set_rollback(rollback, using=None):
"""
Set or unset the "needs rollback" flag -- for *advanced use* only.
When `rollback` is `True`, trigger a rollback when exiting the innermost
enclosing atomic block that has `savepoint=True` (that's the default). Use
this to force a rollback without raising an exception.
When `rollback` is `False`, prevent such a rollback. Use this only after
rolling back to a known-good state! Otherwise, you break the atomic block
and data corruption may occur.
"""
return get_connection(using).set_rollback(rollback)
@contextmanager
def mark_for_rollback_on_error(using=None):
"""
Internal low-level utility to mark a transaction as "needs rollback" when
an exception is raised while not enforcing the enclosed block to be in a
transaction. This is needed by Model.save() and friends to avoid starting a
transaction when in autocommit mode and a single query is executed.
It's equivalent to:
connection = get_connection(using)
if connection.get_autocommit():
yield
else:
with transaction.atomic(using=using, savepoint=False):
yield
but it uses low-level utilities to avoid performance overhead.
"""
try:
yield
except Exception as exc:
connection = get_connection(using)
if connection.in_atomic_block:
connection.needs_rollback = True
connection.rollback_exc = exc
raise
def on_commit(func, using=None, robust=False):
"""
Register `func` to be called when the current transaction is committed.
If the current transaction is rolled back, `func` will not be called.
"""
get_connection(using).on_commit(func, robust)
#################################
# Decorators / context managers #
#################################
class Atomic(ContextDecorator):
"""
Guarantee the atomic execution of a given block.
An instance can be used either as a decorator or as a context manager.
When it's used as a decorator, __call__ wraps the execution of the
decorated function in the instance itself, used as a context manager.
When it's used as a context manager, __enter__ creates a transaction or a
savepoint, depending on whether a transaction is already in progress, and
__exit__ commits the transaction or releases the savepoint on normal exit,
and rolls back the transaction or to the savepoint on exceptions.
It's possible to disable the creation of savepoints if the goal is to
ensure that some code runs within a transaction without creating overhead.
A stack of savepoints identifiers is maintained as an attribute of the
connection. None denotes the absence of a savepoint.
This allows reentrancy even if the same AtomicWrapper is reused. For
example, it's possible to define `oa = atomic('other')` and use `@oa` or
`with oa:` multiple times.
Since database connections are thread-local, this is thread-safe.
An atomic block can be tagged as durable. In this case, raise a
RuntimeError if it's nested within another atomic block. This guarantees
that database changes in a durable block are committed to the database when
the block exists without error.
This is a private API.
"""
def __init__(self, using, savepoint, durable):
self.using = using
self.savepoint = savepoint
self.durable = durable
self._from_testcase = False
def __enter__(self):
connection = get_connection(self.using)
if (
self.durable
and connection.atomic_blocks
and not connection.atomic_blocks[-1]._from_testcase
):
raise RuntimeError(
"A durable atomic block cannot be nested within another "
"atomic block."
)
if not connection.in_atomic_block:
# Reset state when entering an outermost atomic block.
connection.commit_on_exit = True
connection.needs_rollback = False
if not connection.get_autocommit():
# Pretend we're already in an atomic block to bypass the code
# that disables autocommit to enter a transaction, and make a
# note to deal with this case in __exit__.
connection.in_atomic_block = True
connection.commit_on_exit = False
if connection.in_atomic_block:
# We're already in a transaction; create a savepoint, unless we
# were told not to or we're already waiting for a rollback. The
# second condition avoids creating useless savepoints and prevents
# overwriting needs_rollback until the rollback is performed.
if self.savepoint and not connection.needs_rollback:
sid = connection.savepoint()
connection.savepoint_ids.append(sid)
else:
connection.savepoint_ids.append(None)
else:
connection.set_autocommit(
False, force_begin_transaction_with_broken_autocommit=True
)
connection.in_atomic_block = True
if connection.in_atomic_block:
connection.atomic_blocks.append(self)
def __exit__(self, exc_type, exc_value, traceback):
connection = get_connection(self.using)
if connection.in_atomic_block:
connection.atomic_blocks.pop()
if connection.savepoint_ids:
sid = connection.savepoint_ids.pop()
else:
# Prematurely unset this flag to allow using commit or rollback.
connection.in_atomic_block = False
try:
if connection.closed_in_transaction:
# The database will perform a rollback by itself.
# Wait until we exit the outermost block.
pass
elif exc_type is None and not connection.needs_rollback:
if connection.in_atomic_block:
# Release savepoint if there is one
if sid is not None:
try:
connection.savepoint_commit(sid)
except DatabaseError:
try:
connection.savepoint_rollback(sid)
# The savepoint won't be reused. Release it to
# minimize overhead for the database server.
connection.savepoint_commit(sid)
except Error:
# If rolling back to a savepoint fails, mark for
# rollback at a higher level and avoid shadowing
# the original exception.
connection.needs_rollback = True
raise
else:
# Commit transaction
try:
connection.commit()
except DatabaseError:
try:
connection.rollback()
except Error:
# An error during rollback means that something
# went wrong with the connection. Drop it.
connection.close()
raise
else:
# This flag will be set to True again if there isn't a savepoint
# allowing to perform the rollback at this level.
connection.needs_rollback = False
if connection.in_atomic_block:
# Roll back to savepoint if there is one, mark for rollback
# otherwise.
if sid is None:
connection.needs_rollback = True
else:
try:
connection.savepoint_rollback(sid)
# The savepoint won't be reused. Release it to
# minimize overhead for the database server.
connection.savepoint_commit(sid)
except Error:
# If rolling back to a savepoint fails, mark for
# rollback at a higher level and avoid shadowing
# the original exception.
connection.needs_rollback = True
else:
# Roll back transaction
try:
connection.rollback()
except Error:
# An error during rollback means that something
# went wrong with the connection. Drop it.
connection.close()
finally:
# Outermost block exit when autocommit was enabled.
if not connection.in_atomic_block:
if connection.closed_in_transaction:
connection.connection = None
else:
connection.set_autocommit(True)
# Outermost block exit when autocommit was disabled.
elif not connection.savepoint_ids and not connection.commit_on_exit:
if connection.closed_in_transaction:
connection.connection = None
else:
connection.in_atomic_block = False
def atomic(using=None, savepoint=True, durable=False):
# Bare decorator: @atomic -- although the first argument is called
# `using`, it's actually the function being decorated.
if callable(using):
return Atomic(DEFAULT_DB_ALIAS, savepoint, durable)(using)
# Decorator: @atomic(...) or context manager: with atomic(...): ...
else:
return Atomic(using, savepoint, durable)
def _non_atomic_requests(view, using):
try:
view._non_atomic_requests.add(using)
except AttributeError:
view._non_atomic_requests = {using}
return view
def non_atomic_requests(using=None):
if callable(using):
return _non_atomic_requests(using, DEFAULT_DB_ALIAS)
else:
if using is None:
using = DEFAULT_DB_ALIAS
return lambda view: _non_atomic_requests(view, using)
|
castiel248/Convert
|
Lib/site-packages/django/db/transaction.py
|
Python
|
mit
| 12,504 |
import pkgutil
from importlib import import_module
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
# For backwards compatibility with Django < 3.2
from django.utils.connection import ConnectionDoesNotExist # NOQA: F401
from django.utils.connection import BaseConnectionHandler
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
DEFAULT_DB_ALIAS = "default"
DJANGO_VERSION_PICKLE_KEY = "_django_version"
class Error(Exception):
pass
class InterfaceError(Error):
pass
class DatabaseError(Error):
pass
class DataError(DatabaseError):
pass
class OperationalError(DatabaseError):
pass
class IntegrityError(DatabaseError):
pass
class InternalError(DatabaseError):
pass
class ProgrammingError(DatabaseError):
pass
class NotSupportedError(DatabaseError):
pass
class DatabaseErrorWrapper:
"""
Context manager and decorator that reraises backend-specific database
exceptions using Django's common wrappers.
"""
def __init__(self, wrapper):
"""
wrapper is a database wrapper.
It must have a Database attribute defining PEP-249 exceptions.
"""
self.wrapper = wrapper
def __enter__(self):
pass
def __exit__(self, exc_type, exc_value, traceback):
if exc_type is None:
return
for dj_exc_type in (
DataError,
OperationalError,
IntegrityError,
InternalError,
ProgrammingError,
NotSupportedError,
DatabaseError,
InterfaceError,
Error,
):
db_exc_type = getattr(self.wrapper.Database, dj_exc_type.__name__)
if issubclass(exc_type, db_exc_type):
dj_exc_value = dj_exc_type(*exc_value.args)
# Only set the 'errors_occurred' flag for errors that may make
# the connection unusable.
if dj_exc_type not in (DataError, IntegrityError):
self.wrapper.errors_occurred = True
raise dj_exc_value.with_traceback(traceback) from exc_value
def __call__(self, func):
# Note that we are intentionally not using @wraps here for performance
# reasons. Refs #21109.
def inner(*args, **kwargs):
with self:
return func(*args, **kwargs)
return inner
def load_backend(backend_name):
"""
Return a database backend's "base" module given a fully qualified database
backend name, or raise an error if it doesn't exist.
"""
# This backend was renamed in Django 1.9.
if backend_name == "django.db.backends.postgresql_psycopg2":
backend_name = "django.db.backends.postgresql"
try:
return import_module("%s.base" % backend_name)
except ImportError as e_user:
# The database backend wasn't found. Display a helpful error message
# listing all built-in database backends.
import django.db.backends
builtin_backends = [
name
for _, name, ispkg in pkgutil.iter_modules(django.db.backends.__path__)
if ispkg and name not in {"base", "dummy"}
]
if backend_name not in ["django.db.backends.%s" % b for b in builtin_backends]:
backend_reprs = map(repr, sorted(builtin_backends))
raise ImproperlyConfigured(
"%r isn't an available database backend or couldn't be "
"imported. Check the above exception. To use one of the "
"built-in backends, use 'django.db.backends.XXX', where XXX "
"is one of:\n"
" %s" % (backend_name, ", ".join(backend_reprs))
) from e_user
else:
# If there's some other error, this must be an error in Django
raise
class ConnectionHandler(BaseConnectionHandler):
settings_name = "DATABASES"
# Connections needs to still be an actual thread local, as it's truly
# thread-critical. Database backends should use @async_unsafe to protect
# their code from async contexts, but this will give those contexts
# separate connections in case it's needed as well. There's no cleanup
# after async contexts, though, so we don't allow that if we can help it.
thread_critical = True
def configure_settings(self, databases):
databases = super().configure_settings(databases)
if databases == {}:
databases[DEFAULT_DB_ALIAS] = {"ENGINE": "django.db.backends.dummy"}
elif DEFAULT_DB_ALIAS not in databases:
raise ImproperlyConfigured(
f"You must define a '{DEFAULT_DB_ALIAS}' database."
)
elif databases[DEFAULT_DB_ALIAS] == {}:
databases[DEFAULT_DB_ALIAS]["ENGINE"] = "django.db.backends.dummy"
# Configure default settings.
for conn in databases.values():
conn.setdefault("ATOMIC_REQUESTS", False)
conn.setdefault("AUTOCOMMIT", True)
conn.setdefault("ENGINE", "django.db.backends.dummy")
if conn["ENGINE"] == "django.db.backends." or not conn["ENGINE"]:
conn["ENGINE"] = "django.db.backends.dummy"
conn.setdefault("CONN_MAX_AGE", 0)
conn.setdefault("CONN_HEALTH_CHECKS", False)
conn.setdefault("OPTIONS", {})
conn.setdefault("TIME_ZONE", None)
for setting in ["NAME", "USER", "PASSWORD", "HOST", "PORT"]:
conn.setdefault(setting, "")
test_settings = conn.setdefault("TEST", {})
default_test_settings = [
("CHARSET", None),
("COLLATION", None),
("MIGRATE", True),
("MIRROR", None),
("NAME", None),
]
for key, value in default_test_settings:
test_settings.setdefault(key, value)
return databases
@property
def databases(self):
# Maintained for backward compatibility as some 3rd party packages have
# made use of this private API in the past. It is no longer used within
# Django itself.
return self.settings
def create_connection(self, alias):
db = self.settings[alias]
backend = load_backend(db["ENGINE"])
return backend.DatabaseWrapper(db, alias)
class ConnectionRouter:
def __init__(self, routers=None):
"""
If routers is not specified, default to settings.DATABASE_ROUTERS.
"""
self._routers = routers
@cached_property
def routers(self):
if self._routers is None:
self._routers = settings.DATABASE_ROUTERS
routers = []
for r in self._routers:
if isinstance(r, str):
router = import_string(r)()
else:
router = r
routers.append(router)
return routers
def _router_func(action):
def _route_db(self, model, **hints):
chosen_db = None
for router in self.routers:
try:
method = getattr(router, action)
except AttributeError:
# If the router doesn't have a method, skip to the next one.
pass
else:
chosen_db = method(model, **hints)
if chosen_db:
return chosen_db
instance = hints.get("instance")
if instance is not None and instance._state.db:
return instance._state.db
return DEFAULT_DB_ALIAS
return _route_db
db_for_read = _router_func("db_for_read")
db_for_write = _router_func("db_for_write")
def allow_relation(self, obj1, obj2, **hints):
for router in self.routers:
try:
method = router.allow_relation
except AttributeError:
# If the router doesn't have a method, skip to the next one.
pass
else:
allow = method(obj1, obj2, **hints)
if allow is not None:
return allow
return obj1._state.db == obj2._state.db
def allow_migrate(self, db, app_label, **hints):
for router in self.routers:
try:
method = router.allow_migrate
except AttributeError:
# If the router doesn't have a method, skip to the next one.
continue
allow = method(db, app_label, **hints)
if allow is not None:
return allow
return True
def allow_migrate_model(self, db, model):
return self.allow_migrate(
db,
model._meta.app_label,
model_name=model._meta.model_name,
model=model,
)
def get_migratable_models(self, app_config, db, include_auto_created=False):
"""Return app models allowed to be migrated on provided db."""
models = app_config.get_models(include_auto_created=include_auto_created)
return [model for model in models if self.allow_migrate_model(db, model)]
|
castiel248/Convert
|
Lib/site-packages/django/db/utils.py
|
Python
|
mit
| 9,279 |
"""Multi-consumer multi-producer dispatching mechanism
Originally based on pydispatch (BSD) https://pypi.org/project/PyDispatcher/2.0.1/
See license.txt for original license.
Heavily modified for Django's purposes.
"""
from django.dispatch.dispatcher import Signal, receiver # NOQA
|
castiel248/Convert
|
Lib/site-packages/django/dispatch/__init__.py
|
Python
|
mit
| 286 |
import logging
import threading
import weakref
from django.utils.inspect import func_accepts_kwargs
logger = logging.getLogger("django.dispatch")
def _make_id(target):
if hasattr(target, "__func__"):
return (id(target.__self__), id(target.__func__))
return id(target)
NONE_ID = _make_id(None)
# A marker for caching
NO_RECEIVERS = object()
class Signal:
"""
Base class for all signals
Internal attributes:
receivers
{ receiverkey (id) : weakref(receiver) }
"""
def __init__(self, use_caching=False):
"""
Create a new signal.
"""
self.receivers = []
self.lock = threading.Lock()
self.use_caching = use_caching
# For convenience we create empty caches even if they are not used.
# A note about caching: if use_caching is defined, then for each
# distinct sender we cache the receivers that sender has in
# 'sender_receivers_cache'. The cache is cleaned when .connect() or
# .disconnect() is called and populated on send().
self.sender_receivers_cache = weakref.WeakKeyDictionary() if use_caching else {}
self._dead_receivers = False
def connect(self, receiver, sender=None, weak=True, dispatch_uid=None):
"""
Connect receiver to sender for signal.
Arguments:
receiver
A function or an instance method which is to receive signals.
Receivers must be hashable objects.
If weak is True, then receiver must be weak referenceable.
Receivers must be able to accept keyword arguments.
If a receiver is connected with a dispatch_uid argument, it
will not be added if another receiver was already connected
with that dispatch_uid.
sender
The sender to which the receiver should respond. Must either be
a Python object, or None to receive events from any sender.
weak
Whether to use weak references to the receiver. By default, the
module will attempt to use weak references to the receiver
objects. If this parameter is false, then strong references will
be used.
dispatch_uid
An identifier used to uniquely identify a particular instance of
a receiver. This will usually be a string, though it may be
anything hashable.
"""
from django.conf import settings
# If DEBUG is on, check that we got a good receiver
if settings.configured and settings.DEBUG:
if not callable(receiver):
raise TypeError("Signal receivers must be callable.")
# Check for **kwargs
if not func_accepts_kwargs(receiver):
raise ValueError(
"Signal receivers must accept keyword arguments (**kwargs)."
)
if dispatch_uid:
lookup_key = (dispatch_uid, _make_id(sender))
else:
lookup_key = (_make_id(receiver), _make_id(sender))
if weak:
ref = weakref.ref
receiver_object = receiver
# Check for bound methods
if hasattr(receiver, "__self__") and hasattr(receiver, "__func__"):
ref = weakref.WeakMethod
receiver_object = receiver.__self__
receiver = ref(receiver)
weakref.finalize(receiver_object, self._remove_receiver)
with self.lock:
self._clear_dead_receivers()
if not any(r_key == lookup_key for r_key, _ in self.receivers):
self.receivers.append((lookup_key, receiver))
self.sender_receivers_cache.clear()
def disconnect(self, receiver=None, sender=None, dispatch_uid=None):
"""
Disconnect receiver from sender for signal.
If weak references are used, disconnect need not be called. The receiver
will be removed from dispatch automatically.
Arguments:
receiver
The registered receiver to disconnect. May be none if
dispatch_uid is specified.
sender
The registered sender to disconnect
dispatch_uid
the unique identifier of the receiver to disconnect
"""
if dispatch_uid:
lookup_key = (dispatch_uid, _make_id(sender))
else:
lookup_key = (_make_id(receiver), _make_id(sender))
disconnected = False
with self.lock:
self._clear_dead_receivers()
for index in range(len(self.receivers)):
(r_key, _) = self.receivers[index]
if r_key == lookup_key:
disconnected = True
del self.receivers[index]
break
self.sender_receivers_cache.clear()
return disconnected
def has_listeners(self, sender=None):
return bool(self._live_receivers(sender))
def send(self, sender, **named):
"""
Send signal from sender to all connected receivers.
If any receiver raises an error, the error propagates back through send,
terminating the dispatch loop. So it's possible that all receivers
won't be called if an error is raised.
Arguments:
sender
The sender of the signal. Either a specific object or None.
named
Named arguments which will be passed to receivers.
Return a list of tuple pairs [(receiver, response), ... ].
"""
if (
not self.receivers
or self.sender_receivers_cache.get(sender) is NO_RECEIVERS
):
return []
return [
(receiver, receiver(signal=self, sender=sender, **named))
for receiver in self._live_receivers(sender)
]
def send_robust(self, sender, **named):
"""
Send signal from sender to all connected receivers catching errors.
Arguments:
sender
The sender of the signal. Can be any Python object (normally one
registered with a connect if you actually want something to
occur).
named
Named arguments which will be passed to receivers.
Return a list of tuple pairs [(receiver, response), ... ].
If any receiver raises an error (specifically any subclass of
Exception), return the error instance as the result for that receiver.
"""
if (
not self.receivers
or self.sender_receivers_cache.get(sender) is NO_RECEIVERS
):
return []
# Call each receiver with whatever arguments it can accept.
# Return a list of tuple pairs [(receiver, response), ... ].
responses = []
for receiver in self._live_receivers(sender):
try:
response = receiver(signal=self, sender=sender, **named)
except Exception as err:
logger.error(
"Error calling %s in Signal.send_robust() (%s)",
receiver.__qualname__,
err,
exc_info=err,
)
responses.append((receiver, err))
else:
responses.append((receiver, response))
return responses
def _clear_dead_receivers(self):
# Note: caller is assumed to hold self.lock.
if self._dead_receivers:
self._dead_receivers = False
self.receivers = [
r
for r in self.receivers
if not (isinstance(r[1], weakref.ReferenceType) and r[1]() is None)
]
def _live_receivers(self, sender):
"""
Filter sequence of receivers to get resolved, live receivers.
This checks for weak references and resolves them, then returning only
live receivers.
"""
receivers = None
if self.use_caching and not self._dead_receivers:
receivers = self.sender_receivers_cache.get(sender)
# We could end up here with NO_RECEIVERS even if we do check this case in
# .send() prior to calling _live_receivers() due to concurrent .send() call.
if receivers is NO_RECEIVERS:
return []
if receivers is None:
with self.lock:
self._clear_dead_receivers()
senderkey = _make_id(sender)
receivers = []
for (receiverkey, r_senderkey), receiver in self.receivers:
if r_senderkey == NONE_ID or r_senderkey == senderkey:
receivers.append(receiver)
if self.use_caching:
if not receivers:
self.sender_receivers_cache[sender] = NO_RECEIVERS
else:
# Note, we must cache the weakref versions.
self.sender_receivers_cache[sender] = receivers
non_weak_receivers = []
for receiver in receivers:
if isinstance(receiver, weakref.ReferenceType):
# Dereference the weak reference.
receiver = receiver()
if receiver is not None:
non_weak_receivers.append(receiver)
else:
non_weak_receivers.append(receiver)
return non_weak_receivers
def _remove_receiver(self, receiver=None):
# Mark that the self.receivers list has dead weakrefs. If so, we will
# clean those up in connect, disconnect and _live_receivers while
# holding self.lock. Note that doing the cleanup here isn't a good
# idea, _remove_receiver() will be called as side effect of garbage
# collection, and so the call can happen while we are already holding
# self.lock.
self._dead_receivers = True
def receiver(signal, **kwargs):
"""
A decorator for connecting receivers to signals. Used by passing in the
signal (or list of signals) and keyword arguments to connect::
@receiver(post_save, sender=MyModel)
def signal_receiver(sender, **kwargs):
...
@receiver([post_save, post_delete], sender=MyModel)
def signals_receiver(sender, **kwargs):
...
"""
def _decorator(func):
if isinstance(signal, (list, tuple)):
for s in signal:
s.connect(func, **kwargs)
else:
signal.connect(func, **kwargs)
return func
return _decorator
|
castiel248/Convert
|
Lib/site-packages/django/dispatch/dispatcher.py
|
Python
|
mit
| 10,793 |
"""
Django validation and HTML form handling.
"""
from django.core.exceptions import ValidationError # NOQA
from django.forms.boundfield import * # NOQA
from django.forms.fields import * # NOQA
from django.forms.forms import * # NOQA
from django.forms.formsets import * # NOQA
from django.forms.models import * # NOQA
from django.forms.widgets import * # NOQA
|
castiel248/Convert
|
Lib/site-packages/django/forms/__init__.py
|
Python
|
mit
| 368 |
import re
from django.core.exceptions import ValidationError
from django.forms.utils import pretty_name
from django.forms.widgets import MultiWidget, Textarea, TextInput
from django.utils.functional import cached_property
from django.utils.html import format_html, html_safe
from django.utils.translation import gettext_lazy as _
__all__ = ("BoundField",)
@html_safe
class BoundField:
"A Field plus data"
def __init__(self, form, field, name):
self.form = form
self.field = field
self.name = name
self.html_name = form.add_prefix(name)
self.html_initial_name = form.add_initial_prefix(name)
self.html_initial_id = form.add_initial_prefix(self.auto_id)
if self.field.label is None:
self.label = pretty_name(name)
else:
self.label = self.field.label
self.help_text = field.help_text or ""
def __str__(self):
"""Render this field as an HTML widget."""
if self.field.show_hidden_initial:
return self.as_widget() + self.as_hidden(only_initial=True)
return self.as_widget()
@cached_property
def subwidgets(self):
"""
Most widgets yield a single subwidget, but others like RadioSelect and
CheckboxSelectMultiple produce one subwidget for each choice.
This property is cached so that only one database query occurs when
rendering ModelChoiceFields.
"""
id_ = self.field.widget.attrs.get("id") or self.auto_id
attrs = {"id": id_} if id_ else {}
attrs = self.build_widget_attrs(attrs)
return [
BoundWidget(self.field.widget, widget, self.form.renderer)
for widget in self.field.widget.subwidgets(
self.html_name, self.value(), attrs=attrs
)
]
def __bool__(self):
# BoundField evaluates to True even if it doesn't have subwidgets.
return True
def __iter__(self):
return iter(self.subwidgets)
def __len__(self):
return len(self.subwidgets)
def __getitem__(self, idx):
# Prevent unnecessary reevaluation when accessing BoundField's attrs
# from templates.
if not isinstance(idx, (int, slice)):
raise TypeError(
"BoundField indices must be integers or slices, not %s."
% type(idx).__name__
)
return self.subwidgets[idx]
@property
def errors(self):
"""
Return an ErrorList (empty if there are no errors) for this field.
"""
return self.form.errors.get(
self.name, self.form.error_class(renderer=self.form.renderer)
)
def as_widget(self, widget=None, attrs=None, only_initial=False):
"""
Render the field by rendering the passed widget, adding any HTML
attributes passed as attrs. If a widget isn't specified, use the
field's default widget.
"""
widget = widget or self.field.widget
if self.field.localize:
widget.is_localized = True
attrs = attrs or {}
attrs = self.build_widget_attrs(attrs, widget)
if self.auto_id and "id" not in widget.attrs:
attrs.setdefault(
"id", self.html_initial_id if only_initial else self.auto_id
)
if only_initial and self.html_initial_name in self.form.data:
# Propagate the hidden initial value.
value = self.form._widget_data_value(
self.field.hidden_widget(),
self.html_initial_name,
)
else:
value = self.value()
return widget.render(
name=self.html_initial_name if only_initial else self.html_name,
value=value,
attrs=attrs,
renderer=self.form.renderer,
)
def as_text(self, attrs=None, **kwargs):
"""
Return a string of HTML for representing this as an <input type="text">.
"""
return self.as_widget(TextInput(), attrs, **kwargs)
def as_textarea(self, attrs=None, **kwargs):
"""Return a string of HTML for representing this as a <textarea>."""
return self.as_widget(Textarea(), attrs, **kwargs)
def as_hidden(self, attrs=None, **kwargs):
"""
Return a string of HTML for representing this as an <input type="hidden">.
"""
return self.as_widget(self.field.hidden_widget(), attrs, **kwargs)
@property
def data(self):
"""
Return the data for this BoundField, or None if it wasn't given.
"""
return self.form._widget_data_value(self.field.widget, self.html_name)
def value(self):
"""
Return the value for this BoundField, using the initial value if
the form is not bound or the data otherwise.
"""
data = self.initial
if self.form.is_bound:
data = self.field.bound_data(self.data, data)
return self.field.prepare_value(data)
def _has_changed(self):
field = self.field
if field.show_hidden_initial:
hidden_widget = field.hidden_widget()
initial_value = self.form._widget_data_value(
hidden_widget,
self.html_initial_name,
)
try:
initial_value = field.to_python(initial_value)
except ValidationError:
# Always assume data has changed if validation fails.
return True
else:
initial_value = self.initial
return field.has_changed(initial_value, self.data)
def label_tag(self, contents=None, attrs=None, label_suffix=None, tag=None):
"""
Wrap the given contents in a <label>, if the field has an ID attribute.
contents should be mark_safe'd to avoid HTML escaping. If contents
aren't given, use the field's HTML-escaped label.
If attrs are given, use them as HTML attributes on the <label> tag.
label_suffix overrides the form's label_suffix.
"""
contents = contents or self.label
if label_suffix is None:
label_suffix = (
self.field.label_suffix
if self.field.label_suffix is not None
else self.form.label_suffix
)
# Only add the suffix if the label does not end in punctuation.
# Translators: If found as last label character, these punctuation
# characters will prevent the default label_suffix to be appended to the label
if label_suffix and contents and contents[-1] not in _(":?.!"):
contents = format_html("{}{}", contents, label_suffix)
widget = self.field.widget
id_ = widget.attrs.get("id") or self.auto_id
if id_:
id_for_label = widget.id_for_label(id_)
if id_for_label:
attrs = {**(attrs or {}), "for": id_for_label}
if self.field.required and hasattr(self.form, "required_css_class"):
attrs = attrs or {}
if "class" in attrs:
attrs["class"] += " " + self.form.required_css_class
else:
attrs["class"] = self.form.required_css_class
context = {
"field": self,
"label": contents,
"attrs": attrs,
"use_tag": bool(id_),
"tag": tag or "label",
}
return self.form.render(self.form.template_name_label, context)
def legend_tag(self, contents=None, attrs=None, label_suffix=None):
"""
Wrap the given contents in a <legend>, if the field has an ID
attribute. Contents should be mark_safe'd to avoid HTML escaping. If
contents aren't given, use the field's HTML-escaped label.
If attrs are given, use them as HTML attributes on the <legend> tag.
label_suffix overrides the form's label_suffix.
"""
return self.label_tag(contents, attrs, label_suffix, tag="legend")
def css_classes(self, extra_classes=None):
"""
Return a string of space-separated CSS classes for this field.
"""
if hasattr(extra_classes, "split"):
extra_classes = extra_classes.split()
extra_classes = set(extra_classes or [])
if self.errors and hasattr(self.form, "error_css_class"):
extra_classes.add(self.form.error_css_class)
if self.field.required and hasattr(self.form, "required_css_class"):
extra_classes.add(self.form.required_css_class)
return " ".join(extra_classes)
@property
def is_hidden(self):
"""Return True if this BoundField's widget is hidden."""
return self.field.widget.is_hidden
@property
def auto_id(self):
"""
Calculate and return the ID attribute for this BoundField, if the
associated Form has specified auto_id. Return an empty string otherwise.
"""
auto_id = self.form.auto_id # Boolean or string
if auto_id and "%s" in str(auto_id):
return auto_id % self.html_name
elif auto_id:
return self.html_name
return ""
@property
def id_for_label(self):
"""
Wrapper around the field widget's `id_for_label` method.
Useful, for example, for focusing on this field regardless of whether
it has a single widget or a MultiWidget.
"""
widget = self.field.widget
id_ = widget.attrs.get("id") or self.auto_id
return widget.id_for_label(id_)
@cached_property
def initial(self):
return self.form.get_initial_for_field(self.field, self.name)
def build_widget_attrs(self, attrs, widget=None):
widget = widget or self.field.widget
attrs = dict(attrs) # Copy attrs to avoid modifying the argument.
if (
widget.use_required_attribute(self.initial)
and self.field.required
and self.form.use_required_attribute
):
# MultiValueField has require_all_fields: if False, fall back
# on subfields.
if (
hasattr(self.field, "require_all_fields")
and not self.field.require_all_fields
and isinstance(self.field.widget, MultiWidget)
):
for subfield, subwidget in zip(self.field.fields, widget.widgets):
subwidget.attrs["required"] = (
subwidget.use_required_attribute(self.initial)
and subfield.required
)
else:
attrs["required"] = True
if self.field.disabled:
attrs["disabled"] = True
return attrs
@property
def widget_type(self):
return re.sub(
r"widget$|input$", "", self.field.widget.__class__.__name__.lower()
)
@property
def use_fieldset(self):
"""
Return the value of this BoundField widget's use_fieldset attribute.
"""
return self.field.widget.use_fieldset
@html_safe
class BoundWidget:
"""
A container class used for iterating over widgets. This is useful for
widgets that have choices. For example, the following can be used in a
template:
{% for radio in myform.beatles %}
<label for="{{ radio.id_for_label }}">
{{ radio.choice_label }}
<span class="radio">{{ radio.tag }}</span>
</label>
{% endfor %}
"""
def __init__(self, parent_widget, data, renderer):
self.parent_widget = parent_widget
self.data = data
self.renderer = renderer
def __str__(self):
return self.tag(wrap_label=True)
def tag(self, wrap_label=False):
context = {"widget": {**self.data, "wrap_label": wrap_label}}
return self.parent_widget._render(self.template_name, context, self.renderer)
@property
def template_name(self):
if "template_name" in self.data:
return self.data["template_name"]
return self.parent_widget.template_name
@property
def id_for_label(self):
return self.data["attrs"].get("id")
@property
def choice_label(self):
return self.data["label"]
|
castiel248/Convert
|
Lib/site-packages/django/forms/boundfield.py
|
Python
|
mit
| 12,344 |
"""
Field classes.
"""
import copy
import datetime
import json
import math
import operator
import os
import re
import uuid
from decimal import Decimal, DecimalException
from io import BytesIO
from urllib.parse import urlsplit, urlunsplit
from django.core import validators
from django.core.exceptions import ValidationError
from django.forms.boundfield import BoundField
from django.forms.utils import from_current_timezone, to_current_timezone
from django.forms.widgets import (
FILE_INPUT_CONTRADICTION,
CheckboxInput,
ClearableFileInput,
DateInput,
DateTimeInput,
EmailInput,
FileInput,
HiddenInput,
MultipleHiddenInput,
NullBooleanSelect,
NumberInput,
Select,
SelectMultiple,
SplitDateTimeWidget,
SplitHiddenDateTimeWidget,
Textarea,
TextInput,
TimeInput,
URLInput,
)
from django.utils import formats
from django.utils.dateparse import parse_datetime, parse_duration
from django.utils.duration import duration_string
from django.utils.ipv6 import clean_ipv6_address
from django.utils.regex_helper import _lazy_re_compile
from django.utils.translation import gettext_lazy as _
from django.utils.translation import ngettext_lazy
__all__ = (
"Field",
"CharField",
"IntegerField",
"DateField",
"TimeField",
"DateTimeField",
"DurationField",
"RegexField",
"EmailField",
"FileField",
"ImageField",
"URLField",
"BooleanField",
"NullBooleanField",
"ChoiceField",
"MultipleChoiceField",
"ComboField",
"MultiValueField",
"FloatField",
"DecimalField",
"SplitDateTimeField",
"GenericIPAddressField",
"FilePathField",
"JSONField",
"SlugField",
"TypedChoiceField",
"TypedMultipleChoiceField",
"UUIDField",
)
class Field:
widget = TextInput # Default widget to use when rendering this type of Field.
hidden_widget = (
HiddenInput # Default widget to use when rendering this as "hidden".
)
default_validators = [] # Default set of validators
# Add an 'invalid' entry to default_error_message if you want a specific
# field error message not raised by the field validators.
default_error_messages = {
"required": _("This field is required."),
}
empty_values = list(validators.EMPTY_VALUES)
def __init__(
self,
*,
required=True,
widget=None,
label=None,
initial=None,
help_text="",
error_messages=None,
show_hidden_initial=False,
validators=(),
localize=False,
disabled=False,
label_suffix=None,
):
# required -- Boolean that specifies whether the field is required.
# True by default.
# widget -- A Widget class, or instance of a Widget class, that should
# be used for this Field when displaying it. Each Field has a
# default Widget that it'll use if you don't specify this. In
# most cases, the default widget is TextInput.
# label -- A verbose name for this field, for use in displaying this
# field in a form. By default, Django will use a "pretty"
# version of the form field name, if the Field is part of a
# Form.
# initial -- A value to use in this Field's initial display. This value
# is *not* used as a fallback if data isn't given.
# help_text -- An optional string to use as "help text" for this Field.
# error_messages -- An optional dictionary to override the default
# messages that the field will raise.
# show_hidden_initial -- Boolean that specifies if it is needed to render a
# hidden widget with initial value after widget.
# validators -- List of additional validators to use
# localize -- Boolean that specifies if the field should be localized.
# disabled -- Boolean that specifies whether the field is disabled, that
# is its widget is shown in the form but not editable.
# label_suffix -- Suffix to be added to the label. Overrides
# form's label_suffix.
self.required, self.label, self.initial = required, label, initial
self.show_hidden_initial = show_hidden_initial
self.help_text = help_text
self.disabled = disabled
self.label_suffix = label_suffix
widget = widget or self.widget
if isinstance(widget, type):
widget = widget()
else:
widget = copy.deepcopy(widget)
# Trigger the localization machinery if needed.
self.localize = localize
if self.localize:
widget.is_localized = True
# Let the widget know whether it should display as required.
widget.is_required = self.required
# Hook into self.widget_attrs() for any Field-specific HTML attributes.
extra_attrs = self.widget_attrs(widget)
if extra_attrs:
widget.attrs.update(extra_attrs)
self.widget = widget
messages = {}
for c in reversed(self.__class__.__mro__):
messages.update(getattr(c, "default_error_messages", {}))
messages.update(error_messages or {})
self.error_messages = messages
self.validators = [*self.default_validators, *validators]
super().__init__()
def prepare_value(self, value):
return value
def to_python(self, value):
return value
def validate(self, value):
if value in self.empty_values and self.required:
raise ValidationError(self.error_messages["required"], code="required")
def run_validators(self, value):
if value in self.empty_values:
return
errors = []
for v in self.validators:
try:
v(value)
except ValidationError as e:
if hasattr(e, "code") and e.code in self.error_messages:
e.message = self.error_messages[e.code]
errors.extend(e.error_list)
if errors:
raise ValidationError(errors)
def clean(self, value):
"""
Validate the given value and return its "cleaned" value as an
appropriate Python object. Raise ValidationError for any errors.
"""
value = self.to_python(value)
self.validate(value)
self.run_validators(value)
return value
def bound_data(self, data, initial):
"""
Return the value that should be shown for this field on render of a
bound form, given the submitted POST data for the field and the initial
data, if any.
For most fields, this will simply be data; FileFields need to handle it
a bit differently.
"""
if self.disabled:
return initial
return data
def widget_attrs(self, widget):
"""
Given a Widget instance (*not* a Widget class), return a dictionary of
any HTML attributes that should be added to the Widget, based on this
Field.
"""
return {}
def has_changed(self, initial, data):
"""Return True if data differs from initial."""
# Always return False if the field is disabled since self.bound_data
# always uses the initial value in this case.
if self.disabled:
return False
try:
data = self.to_python(data)
if hasattr(self, "_coerce"):
return self._coerce(data) != self._coerce(initial)
except ValidationError:
return True
# For purposes of seeing whether something has changed, None is
# the same as an empty string, if the data or initial value we get
# is None, replace it with ''.
initial_value = initial if initial is not None else ""
data_value = data if data is not None else ""
return initial_value != data_value
def get_bound_field(self, form, field_name):
"""
Return a BoundField instance that will be used when accessing the form
field in a template.
"""
return BoundField(form, self, field_name)
def __deepcopy__(self, memo):
result = copy.copy(self)
memo[id(self)] = result
result.widget = copy.deepcopy(self.widget, memo)
result.error_messages = self.error_messages.copy()
result.validators = self.validators[:]
return result
class CharField(Field):
def __init__(
self, *, max_length=None, min_length=None, strip=True, empty_value="", **kwargs
):
self.max_length = max_length
self.min_length = min_length
self.strip = strip
self.empty_value = empty_value
super().__init__(**kwargs)
if min_length is not None:
self.validators.append(validators.MinLengthValidator(int(min_length)))
if max_length is not None:
self.validators.append(validators.MaxLengthValidator(int(max_length)))
self.validators.append(validators.ProhibitNullCharactersValidator())
def to_python(self, value):
"""Return a string."""
if value not in self.empty_values:
value = str(value)
if self.strip:
value = value.strip()
if value in self.empty_values:
return self.empty_value
return value
def widget_attrs(self, widget):
attrs = super().widget_attrs(widget)
if self.max_length is not None and not widget.is_hidden:
# The HTML attribute is maxlength, not max_length.
attrs["maxlength"] = str(self.max_length)
if self.min_length is not None and not widget.is_hidden:
# The HTML attribute is minlength, not min_length.
attrs["minlength"] = str(self.min_length)
return attrs
class IntegerField(Field):
widget = NumberInput
default_error_messages = {
"invalid": _("Enter a whole number."),
}
re_decimal = _lazy_re_compile(r"\.0*\s*$")
def __init__(self, *, max_value=None, min_value=None, step_size=None, **kwargs):
self.max_value, self.min_value, self.step_size = max_value, min_value, step_size
if kwargs.get("localize") and self.widget == NumberInput:
# Localized number input is not well supported on most browsers
kwargs.setdefault("widget", super().widget)
super().__init__(**kwargs)
if max_value is not None:
self.validators.append(validators.MaxValueValidator(max_value))
if min_value is not None:
self.validators.append(validators.MinValueValidator(min_value))
if step_size is not None:
self.validators.append(validators.StepValueValidator(step_size))
def to_python(self, value):
"""
Validate that int() can be called on the input. Return the result
of int() or None for empty values.
"""
value = super().to_python(value)
if value in self.empty_values:
return None
if self.localize:
value = formats.sanitize_separators(value)
# Strip trailing decimal and zeros.
try:
value = int(self.re_decimal.sub("", str(value)))
except (ValueError, TypeError):
raise ValidationError(self.error_messages["invalid"], code="invalid")
return value
def widget_attrs(self, widget):
attrs = super().widget_attrs(widget)
if isinstance(widget, NumberInput):
if self.min_value is not None:
attrs["min"] = self.min_value
if self.max_value is not None:
attrs["max"] = self.max_value
if self.step_size is not None:
attrs["step"] = self.step_size
return attrs
class FloatField(IntegerField):
default_error_messages = {
"invalid": _("Enter a number."),
}
def to_python(self, value):
"""
Validate that float() can be called on the input. Return the result
of float() or None for empty values.
"""
value = super(IntegerField, self).to_python(value)
if value in self.empty_values:
return None
if self.localize:
value = formats.sanitize_separators(value)
try:
value = float(value)
except (ValueError, TypeError):
raise ValidationError(self.error_messages["invalid"], code="invalid")
return value
def validate(self, value):
super().validate(value)
if value in self.empty_values:
return
if not math.isfinite(value):
raise ValidationError(self.error_messages["invalid"], code="invalid")
def widget_attrs(self, widget):
attrs = super().widget_attrs(widget)
if isinstance(widget, NumberInput) and "step" not in widget.attrs:
if self.step_size is not None:
step = str(self.step_size)
else:
step = "any"
attrs.setdefault("step", step)
return attrs
class DecimalField(IntegerField):
default_error_messages = {
"invalid": _("Enter a number."),
}
def __init__(
self,
*,
max_value=None,
min_value=None,
max_digits=None,
decimal_places=None,
**kwargs,
):
self.max_digits, self.decimal_places = max_digits, decimal_places
super().__init__(max_value=max_value, min_value=min_value, **kwargs)
self.validators.append(validators.DecimalValidator(max_digits, decimal_places))
def to_python(self, value):
"""
Validate that the input is a decimal number. Return a Decimal
instance or None for empty values. Ensure that there are no more
than max_digits in the number and no more than decimal_places digits
after the decimal point.
"""
if value in self.empty_values:
return None
if self.localize:
value = formats.sanitize_separators(value)
try:
value = Decimal(str(value))
except DecimalException:
raise ValidationError(self.error_messages["invalid"], code="invalid")
return value
def validate(self, value):
super().validate(value)
if value in self.empty_values:
return
if not value.is_finite():
raise ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def widget_attrs(self, widget):
attrs = super().widget_attrs(widget)
if isinstance(widget, NumberInput) and "step" not in widget.attrs:
if self.decimal_places is not None:
# Use exponential notation for small values since they might
# be parsed as 0 otherwise. ref #20765
step = str(Decimal(1).scaleb(-self.decimal_places)).lower()
else:
step = "any"
attrs.setdefault("step", step)
return attrs
class BaseTemporalField(Field):
def __init__(self, *, input_formats=None, **kwargs):
super().__init__(**kwargs)
if input_formats is not None:
self.input_formats = input_formats
def to_python(self, value):
value = value.strip()
# Try to strptime against each input format.
for format in self.input_formats:
try:
return self.strptime(value, format)
except (ValueError, TypeError):
continue
raise ValidationError(self.error_messages["invalid"], code="invalid")
def strptime(self, value, format):
raise NotImplementedError("Subclasses must define this method.")
class DateField(BaseTemporalField):
widget = DateInput
input_formats = formats.get_format_lazy("DATE_INPUT_FORMATS")
default_error_messages = {
"invalid": _("Enter a valid date."),
}
def to_python(self, value):
"""
Validate that the input can be converted to a date. Return a Python
datetime.date object.
"""
if value in self.empty_values:
return None
if isinstance(value, datetime.datetime):
return value.date()
if isinstance(value, datetime.date):
return value
return super().to_python(value)
def strptime(self, value, format):
return datetime.datetime.strptime(value, format).date()
class TimeField(BaseTemporalField):
widget = TimeInput
input_formats = formats.get_format_lazy("TIME_INPUT_FORMATS")
default_error_messages = {"invalid": _("Enter a valid time.")}
def to_python(self, value):
"""
Validate that the input can be converted to a time. Return a Python
datetime.time object.
"""
if value in self.empty_values:
return None
if isinstance(value, datetime.time):
return value
return super().to_python(value)
def strptime(self, value, format):
return datetime.datetime.strptime(value, format).time()
class DateTimeFormatsIterator:
def __iter__(self):
yield from formats.get_format("DATETIME_INPUT_FORMATS")
yield from formats.get_format("DATE_INPUT_FORMATS")
class DateTimeField(BaseTemporalField):
widget = DateTimeInput
input_formats = DateTimeFormatsIterator()
default_error_messages = {
"invalid": _("Enter a valid date/time."),
}
def prepare_value(self, value):
if isinstance(value, datetime.datetime):
value = to_current_timezone(value)
return value
def to_python(self, value):
"""
Validate that the input can be converted to a datetime. Return a
Python datetime.datetime object.
"""
if value in self.empty_values:
return None
if isinstance(value, datetime.datetime):
return from_current_timezone(value)
if isinstance(value, datetime.date):
result = datetime.datetime(value.year, value.month, value.day)
return from_current_timezone(result)
try:
result = parse_datetime(value.strip())
except ValueError:
raise ValidationError(self.error_messages["invalid"], code="invalid")
if not result:
result = super().to_python(value)
return from_current_timezone(result)
def strptime(self, value, format):
return datetime.datetime.strptime(value, format)
class DurationField(Field):
default_error_messages = {
"invalid": _("Enter a valid duration."),
"overflow": _("The number of days must be between {min_days} and {max_days}."),
}
def prepare_value(self, value):
if isinstance(value, datetime.timedelta):
return duration_string(value)
return value
def to_python(self, value):
if value in self.empty_values:
return None
if isinstance(value, datetime.timedelta):
return value
try:
value = parse_duration(str(value))
except OverflowError:
raise ValidationError(
self.error_messages["overflow"].format(
min_days=datetime.timedelta.min.days,
max_days=datetime.timedelta.max.days,
),
code="overflow",
)
if value is None:
raise ValidationError(self.error_messages["invalid"], code="invalid")
return value
class RegexField(CharField):
def __init__(self, regex, **kwargs):
"""
regex can be either a string or a compiled regular expression object.
"""
kwargs.setdefault("strip", False)
super().__init__(**kwargs)
self._set_regex(regex)
def _get_regex(self):
return self._regex
def _set_regex(self, regex):
if isinstance(regex, str):
regex = re.compile(regex)
self._regex = regex
if (
hasattr(self, "_regex_validator")
and self._regex_validator in self.validators
):
self.validators.remove(self._regex_validator)
self._regex_validator = validators.RegexValidator(regex=regex)
self.validators.append(self._regex_validator)
regex = property(_get_regex, _set_regex)
class EmailField(CharField):
widget = EmailInput
default_validators = [validators.validate_email]
def __init__(self, **kwargs):
super().__init__(strip=True, **kwargs)
class FileField(Field):
widget = ClearableFileInput
default_error_messages = {
"invalid": _("No file was submitted. Check the encoding type on the form."),
"missing": _("No file was submitted."),
"empty": _("The submitted file is empty."),
"max_length": ngettext_lazy(
"Ensure this filename has at most %(max)d character (it has %(length)d).",
"Ensure this filename has at most %(max)d characters (it has %(length)d).",
"max",
),
"contradiction": _(
"Please either submit a file or check the clear checkbox, not both."
),
}
def __init__(self, *, max_length=None, allow_empty_file=False, **kwargs):
self.max_length = max_length
self.allow_empty_file = allow_empty_file
super().__init__(**kwargs)
def to_python(self, data):
if data in self.empty_values:
return None
# UploadedFile objects should have name and size attributes.
try:
file_name = data.name
file_size = data.size
except AttributeError:
raise ValidationError(self.error_messages["invalid"], code="invalid")
if self.max_length is not None and len(file_name) > self.max_length:
params = {"max": self.max_length, "length": len(file_name)}
raise ValidationError(
self.error_messages["max_length"], code="max_length", params=params
)
if not file_name:
raise ValidationError(self.error_messages["invalid"], code="invalid")
if not self.allow_empty_file and not file_size:
raise ValidationError(self.error_messages["empty"], code="empty")
return data
def clean(self, data, initial=None):
# If the widget got contradictory inputs, we raise a validation error
if data is FILE_INPUT_CONTRADICTION:
raise ValidationError(
self.error_messages["contradiction"], code="contradiction"
)
# False means the field value should be cleared; further validation is
# not needed.
if data is False:
if not self.required:
return False
# If the field is required, clearing is not possible (the widget
# shouldn't return False data in that case anyway). False is not
# in self.empty_value; if a False value makes it this far
# it should be validated from here on out as None (so it will be
# caught by the required check).
data = None
if not data and initial:
return initial
return super().clean(data)
def bound_data(self, _, initial):
return initial
def has_changed(self, initial, data):
return not self.disabled and data is not None
class ImageField(FileField):
default_validators = [validators.validate_image_file_extension]
default_error_messages = {
"invalid_image": _(
"Upload a valid image. The file you uploaded was either not an "
"image or a corrupted image."
),
}
def to_python(self, data):
"""
Check that the file-upload field data contains a valid image (GIF, JPG,
PNG, etc. -- whatever Pillow supports).
"""
f = super().to_python(data)
if f is None:
return None
from PIL import Image
# We need to get a file object for Pillow. We might have a path or we might
# have to read the data into memory.
if hasattr(data, "temporary_file_path"):
file = data.temporary_file_path()
else:
if hasattr(data, "read"):
file = BytesIO(data.read())
else:
file = BytesIO(data["content"])
try:
# load() could spot a truncated JPEG, but it loads the entire
# image in memory, which is a DoS vector. See #3848 and #18520.
image = Image.open(file)
# verify() must be called immediately after the constructor.
image.verify()
# Annotating so subclasses can reuse it for their own validation
f.image = image
# Pillow doesn't detect the MIME type of all formats. In those
# cases, content_type will be None.
f.content_type = Image.MIME.get(image.format)
except Exception as exc:
# Pillow doesn't recognize it as an image.
raise ValidationError(
self.error_messages["invalid_image"],
code="invalid_image",
) from exc
if hasattr(f, "seek") and callable(f.seek):
f.seek(0)
return f
def widget_attrs(self, widget):
attrs = super().widget_attrs(widget)
if isinstance(widget, FileInput) and "accept" not in widget.attrs:
attrs.setdefault("accept", "image/*")
return attrs
class URLField(CharField):
widget = URLInput
default_error_messages = {
"invalid": _("Enter a valid URL."),
}
default_validators = [validators.URLValidator()]
def __init__(self, **kwargs):
super().__init__(strip=True, **kwargs)
def to_python(self, value):
def split_url(url):
"""
Return a list of url parts via urlparse.urlsplit(), or raise
ValidationError for some malformed URLs.
"""
try:
return list(urlsplit(url))
except ValueError:
# urlparse.urlsplit can raise a ValueError with some
# misformatted URLs.
raise ValidationError(self.error_messages["invalid"], code="invalid")
value = super().to_python(value)
if value:
url_fields = split_url(value)
if not url_fields[0]:
# If no URL scheme given, assume http://
url_fields[0] = "http"
if not url_fields[1]:
# Assume that if no domain is provided, that the path segment
# contains the domain.
url_fields[1] = url_fields[2]
url_fields[2] = ""
# Rebuild the url_fields list, since the domain segment may now
# contain the path too.
url_fields = split_url(urlunsplit(url_fields))
value = urlunsplit(url_fields)
return value
class BooleanField(Field):
widget = CheckboxInput
def to_python(self, value):
"""Return a Python boolean object."""
# Explicitly check for the string 'False', which is what a hidden field
# will submit for False. Also check for '0', since this is what
# RadioSelect will provide. Because bool("True") == bool('1') == True,
# we don't need to handle that explicitly.
if isinstance(value, str) and value.lower() in ("false", "0"):
value = False
else:
value = bool(value)
return super().to_python(value)
def validate(self, value):
if not value and self.required:
raise ValidationError(self.error_messages["required"], code="required")
def has_changed(self, initial, data):
if self.disabled:
return False
# Sometimes data or initial may be a string equivalent of a boolean
# so we should run it through to_python first to get a boolean value
return self.to_python(initial) != self.to_python(data)
class NullBooleanField(BooleanField):
"""
A field whose valid values are None, True, and False. Clean invalid values
to None.
"""
widget = NullBooleanSelect
def to_python(self, value):
"""
Explicitly check for the string 'True' and 'False', which is what a
hidden field will submit for True and False, for 'true' and 'false',
which are likely to be returned by JavaScript serializations of forms,
and for '1' and '0', which is what a RadioField will submit. Unlike
the Booleanfield, this field must check for True because it doesn't
use the bool() function.
"""
if value in (True, "True", "true", "1"):
return True
elif value in (False, "False", "false", "0"):
return False
else:
return None
def validate(self, value):
pass
class CallableChoiceIterator:
def __init__(self, choices_func):
self.choices_func = choices_func
def __iter__(self):
yield from self.choices_func()
class ChoiceField(Field):
widget = Select
default_error_messages = {
"invalid_choice": _(
"Select a valid choice. %(value)s is not one of the available choices."
),
}
def __init__(self, *, choices=(), **kwargs):
super().__init__(**kwargs)
self.choices = choices
def __deepcopy__(self, memo):
result = super().__deepcopy__(memo)
result._choices = copy.deepcopy(self._choices, memo)
return result
def _get_choices(self):
return self._choices
def _set_choices(self, value):
# Setting choices also sets the choices on the widget.
# choices can be any iterable, but we call list() on it because
# it will be consumed more than once.
if callable(value):
value = CallableChoiceIterator(value)
else:
value = list(value)
self._choices = self.widget.choices = value
choices = property(_get_choices, _set_choices)
def to_python(self, value):
"""Return a string."""
if value in self.empty_values:
return ""
return str(value)
def validate(self, value):
"""Validate that the input is in self.choices."""
super().validate(value)
if value and not self.valid_value(value):
raise ValidationError(
self.error_messages["invalid_choice"],
code="invalid_choice",
params={"value": value},
)
def valid_value(self, value):
"""Check to see if the provided value is a valid choice."""
text_value = str(value)
for k, v in self.choices:
if isinstance(v, (list, tuple)):
# This is an optgroup, so look inside the group for options
for k2, v2 in v:
if value == k2 or text_value == str(k2):
return True
else:
if value == k or text_value == str(k):
return True
return False
class TypedChoiceField(ChoiceField):
def __init__(self, *, coerce=lambda val: val, empty_value="", **kwargs):
self.coerce = coerce
self.empty_value = empty_value
super().__init__(**kwargs)
def _coerce(self, value):
"""
Validate that the value can be coerced to the right type (if not empty).
"""
if value == self.empty_value or value in self.empty_values:
return self.empty_value
try:
value = self.coerce(value)
except (ValueError, TypeError, ValidationError):
raise ValidationError(
self.error_messages["invalid_choice"],
code="invalid_choice",
params={"value": value},
)
return value
def clean(self, value):
value = super().clean(value)
return self._coerce(value)
class MultipleChoiceField(ChoiceField):
hidden_widget = MultipleHiddenInput
widget = SelectMultiple
default_error_messages = {
"invalid_choice": _(
"Select a valid choice. %(value)s is not one of the available choices."
),
"invalid_list": _("Enter a list of values."),
}
def to_python(self, value):
if not value:
return []
elif not isinstance(value, (list, tuple)):
raise ValidationError(
self.error_messages["invalid_list"], code="invalid_list"
)
return [str(val) for val in value]
def validate(self, value):
"""Validate that the input is a list or tuple."""
if self.required and not value:
raise ValidationError(self.error_messages["required"], code="required")
# Validate that each value in the value list is in self.choices.
for val in value:
if not self.valid_value(val):
raise ValidationError(
self.error_messages["invalid_choice"],
code="invalid_choice",
params={"value": val},
)
def has_changed(self, initial, data):
if self.disabled:
return False
if initial is None:
initial = []
if data is None:
data = []
if len(initial) != len(data):
return True
initial_set = {str(value) for value in initial}
data_set = {str(value) for value in data}
return data_set != initial_set
class TypedMultipleChoiceField(MultipleChoiceField):
def __init__(self, *, coerce=lambda val: val, **kwargs):
self.coerce = coerce
self.empty_value = kwargs.pop("empty_value", [])
super().__init__(**kwargs)
def _coerce(self, value):
"""
Validate that the values are in self.choices and can be coerced to the
right type.
"""
if value == self.empty_value or value in self.empty_values:
return self.empty_value
new_value = []
for choice in value:
try:
new_value.append(self.coerce(choice))
except (ValueError, TypeError, ValidationError):
raise ValidationError(
self.error_messages["invalid_choice"],
code="invalid_choice",
params={"value": choice},
)
return new_value
def clean(self, value):
value = super().clean(value)
return self._coerce(value)
def validate(self, value):
if value != self.empty_value:
super().validate(value)
elif self.required:
raise ValidationError(self.error_messages["required"], code="required")
class ComboField(Field):
"""
A Field whose clean() method calls multiple Field clean() methods.
"""
def __init__(self, fields, **kwargs):
super().__init__(**kwargs)
# Set 'required' to False on the individual fields, because the
# required validation will be handled by ComboField, not by those
# individual fields.
for f in fields:
f.required = False
self.fields = fields
def clean(self, value):
"""
Validate the given value against all of self.fields, which is a
list of Field instances.
"""
super().clean(value)
for field in self.fields:
value = field.clean(value)
return value
class MultiValueField(Field):
"""
Aggregate the logic of multiple Fields.
Its clean() method takes a "decompressed" list of values, which are then
cleaned into a single value according to self.fields. Each value in
this list is cleaned by the corresponding field -- the first value is
cleaned by the first field, the second value is cleaned by the second
field, etc. Once all fields are cleaned, the list of clean values is
"compressed" into a single value.
Subclasses should not have to implement clean(). Instead, they must
implement compress(), which takes a list of valid values and returns a
"compressed" version of those values -- a single value.
You'll probably want to use this with MultiWidget.
"""
default_error_messages = {
"invalid": _("Enter a list of values."),
"incomplete": _("Enter a complete value."),
}
def __init__(self, fields, *, require_all_fields=True, **kwargs):
self.require_all_fields = require_all_fields
super().__init__(**kwargs)
for f in fields:
f.error_messages.setdefault("incomplete", self.error_messages["incomplete"])
if self.disabled:
f.disabled = True
if self.require_all_fields:
# Set 'required' to False on the individual fields, because the
# required validation will be handled by MultiValueField, not
# by those individual fields.
f.required = False
self.fields = fields
def __deepcopy__(self, memo):
result = super().__deepcopy__(memo)
result.fields = tuple(x.__deepcopy__(memo) for x in self.fields)
return result
def validate(self, value):
pass
def clean(self, value):
"""
Validate every value in the given list. A value is validated against
the corresponding Field in self.fields.
For example, if this MultiValueField was instantiated with
fields=(DateField(), TimeField()), clean() would call
DateField.clean(value[0]) and TimeField.clean(value[1]).
"""
clean_data = []
errors = []
if self.disabled and not isinstance(value, list):
value = self.widget.decompress(value)
if not value or isinstance(value, (list, tuple)):
if not value or not [v for v in value if v not in self.empty_values]:
if self.required:
raise ValidationError(
self.error_messages["required"], code="required"
)
else:
return self.compress([])
else:
raise ValidationError(self.error_messages["invalid"], code="invalid")
for i, field in enumerate(self.fields):
try:
field_value = value[i]
except IndexError:
field_value = None
if field_value in self.empty_values:
if self.require_all_fields:
# Raise a 'required' error if the MultiValueField is
# required and any field is empty.
if self.required:
raise ValidationError(
self.error_messages["required"], code="required"
)
elif field.required:
# Otherwise, add an 'incomplete' error to the list of
# collected errors and skip field cleaning, if a required
# field is empty.
if field.error_messages["incomplete"] not in errors:
errors.append(field.error_messages["incomplete"])
continue
try:
clean_data.append(field.clean(field_value))
except ValidationError as e:
# Collect all validation errors in a single list, which we'll
# raise at the end of clean(), rather than raising a single
# exception for the first error we encounter. Skip duplicates.
errors.extend(m for m in e.error_list if m not in errors)
if errors:
raise ValidationError(errors)
out = self.compress(clean_data)
self.validate(out)
self.run_validators(out)
return out
def compress(self, data_list):
"""
Return a single value for the given list of values. The values can be
assumed to be valid.
For example, if this MultiValueField was instantiated with
fields=(DateField(), TimeField()), this might return a datetime
object created by combining the date and time in data_list.
"""
raise NotImplementedError("Subclasses must implement this method.")
def has_changed(self, initial, data):
if self.disabled:
return False
if initial is None:
initial = ["" for x in range(0, len(data))]
else:
if not isinstance(initial, list):
initial = self.widget.decompress(initial)
for field, initial, data in zip(self.fields, initial, data):
try:
initial = field.to_python(initial)
except ValidationError:
return True
if field.has_changed(initial, data):
return True
return False
class FilePathField(ChoiceField):
def __init__(
self,
path,
*,
match=None,
recursive=False,
allow_files=True,
allow_folders=False,
**kwargs,
):
self.path, self.match, self.recursive = path, match, recursive
self.allow_files, self.allow_folders = allow_files, allow_folders
super().__init__(choices=(), **kwargs)
if self.required:
self.choices = []
else:
self.choices = [("", "---------")]
if self.match is not None:
self.match_re = re.compile(self.match)
if recursive:
for root, dirs, files in sorted(os.walk(self.path)):
if self.allow_files:
for f in sorted(files):
if self.match is None or self.match_re.search(f):
f = os.path.join(root, f)
self.choices.append((f, f.replace(path, "", 1)))
if self.allow_folders:
for f in sorted(dirs):
if f == "__pycache__":
continue
if self.match is None or self.match_re.search(f):
f = os.path.join(root, f)
self.choices.append((f, f.replace(path, "", 1)))
else:
choices = []
with os.scandir(self.path) as entries:
for f in entries:
if f.name == "__pycache__":
continue
if (
(self.allow_files and f.is_file())
or (self.allow_folders and f.is_dir())
) and (self.match is None or self.match_re.search(f.name)):
choices.append((f.path, f.name))
choices.sort(key=operator.itemgetter(1))
self.choices.extend(choices)
self.widget.choices = self.choices
class SplitDateTimeField(MultiValueField):
widget = SplitDateTimeWidget
hidden_widget = SplitHiddenDateTimeWidget
default_error_messages = {
"invalid_date": _("Enter a valid date."),
"invalid_time": _("Enter a valid time."),
}
def __init__(self, *, input_date_formats=None, input_time_formats=None, **kwargs):
errors = self.default_error_messages.copy()
if "error_messages" in kwargs:
errors.update(kwargs["error_messages"])
localize = kwargs.get("localize", False)
fields = (
DateField(
input_formats=input_date_formats,
error_messages={"invalid": errors["invalid_date"]},
localize=localize,
),
TimeField(
input_formats=input_time_formats,
error_messages={"invalid": errors["invalid_time"]},
localize=localize,
),
)
super().__init__(fields, **kwargs)
def compress(self, data_list):
if data_list:
# Raise a validation error if time or date is empty
# (possible if SplitDateTimeField has required=False).
if data_list[0] in self.empty_values:
raise ValidationError(
self.error_messages["invalid_date"], code="invalid_date"
)
if data_list[1] in self.empty_values:
raise ValidationError(
self.error_messages["invalid_time"], code="invalid_time"
)
result = datetime.datetime.combine(*data_list)
return from_current_timezone(result)
return None
class GenericIPAddressField(CharField):
def __init__(self, *, protocol="both", unpack_ipv4=False, **kwargs):
self.unpack_ipv4 = unpack_ipv4
self.default_validators = validators.ip_address_validators(
protocol, unpack_ipv4
)[0]
super().__init__(**kwargs)
def to_python(self, value):
if value in self.empty_values:
return ""
value = value.strip()
if value and ":" in value:
return clean_ipv6_address(value, self.unpack_ipv4)
return value
class SlugField(CharField):
default_validators = [validators.validate_slug]
def __init__(self, *, allow_unicode=False, **kwargs):
self.allow_unicode = allow_unicode
if self.allow_unicode:
self.default_validators = [validators.validate_unicode_slug]
super().__init__(**kwargs)
class UUIDField(CharField):
default_error_messages = {
"invalid": _("Enter a valid UUID."),
}
def prepare_value(self, value):
if isinstance(value, uuid.UUID):
return str(value)
return value
def to_python(self, value):
value = super().to_python(value)
if value in self.empty_values:
return None
if not isinstance(value, uuid.UUID):
try:
value = uuid.UUID(value)
except ValueError:
raise ValidationError(self.error_messages["invalid"], code="invalid")
return value
class InvalidJSONInput(str):
pass
class JSONString(str):
pass
class JSONField(CharField):
default_error_messages = {
"invalid": _("Enter a valid JSON."),
}
widget = Textarea
def __init__(self, encoder=None, decoder=None, **kwargs):
self.encoder = encoder
self.decoder = decoder
super().__init__(**kwargs)
def to_python(self, value):
if self.disabled:
return value
if value in self.empty_values:
return None
elif isinstance(value, (list, dict, int, float, JSONString)):
return value
try:
converted = json.loads(value, cls=self.decoder)
except json.JSONDecodeError:
raise ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
if isinstance(converted, str):
return JSONString(converted)
else:
return converted
def bound_data(self, data, initial):
if self.disabled:
return initial
if data is None:
return None
try:
return json.loads(data, cls=self.decoder)
except json.JSONDecodeError:
return InvalidJSONInput(data)
def prepare_value(self, value):
if isinstance(value, InvalidJSONInput):
return value
return json.dumps(value, ensure_ascii=False, cls=self.encoder)
def has_changed(self, initial, data):
if super().has_changed(initial, data):
return True
# For purposes of seeing whether something has changed, True isn't the
# same as 1 and the order of keys doesn't matter.
return json.dumps(initial, sort_keys=True, cls=self.encoder) != json.dumps(
self.to_python(data), sort_keys=True, cls=self.encoder
)
|
castiel248/Convert
|
Lib/site-packages/django/forms/fields.py
|
Python
|
mit
| 48,253 |
"""
Form classes
"""
import copy
import datetime
import warnings
from django.core.exceptions import NON_FIELD_ERRORS, ValidationError
from django.forms.fields import Field, FileField
from django.forms.utils import ErrorDict, ErrorList, RenderableFormMixin
from django.forms.widgets import Media, MediaDefiningClass
from django.utils.datastructures import MultiValueDict
from django.utils.deprecation import RemovedInDjango50Warning
from django.utils.functional import cached_property
from django.utils.html import conditional_escape
from django.utils.safestring import SafeString, mark_safe
from django.utils.translation import gettext as _
from .renderers import get_default_renderer
__all__ = ("BaseForm", "Form")
class DeclarativeFieldsMetaclass(MediaDefiningClass):
"""Collect Fields declared on the base classes."""
def __new__(mcs, name, bases, attrs):
# Collect fields from current class and remove them from attrs.
attrs["declared_fields"] = {
key: attrs.pop(key)
for key, value in list(attrs.items())
if isinstance(value, Field)
}
new_class = super().__new__(mcs, name, bases, attrs)
# Walk through the MRO.
declared_fields = {}
for base in reversed(new_class.__mro__):
# Collect fields from base class.
if hasattr(base, "declared_fields"):
declared_fields.update(base.declared_fields)
# Field shadowing.
for attr, value in base.__dict__.items():
if value is None and attr in declared_fields:
declared_fields.pop(attr)
new_class.base_fields = declared_fields
new_class.declared_fields = declared_fields
return new_class
class BaseForm(RenderableFormMixin):
"""
The main implementation of all the Form logic. Note that this class is
different than Form. See the comments by the Form class for more info. Any
improvements to the form API should be made to this class, not to the Form
class.
"""
default_renderer = None
field_order = None
prefix = None
use_required_attribute = True
template_name_div = "django/forms/div.html"
template_name_p = "django/forms/p.html"
template_name_table = "django/forms/table.html"
template_name_ul = "django/forms/ul.html"
template_name_label = "django/forms/label.html"
def __init__(
self,
data=None,
files=None,
auto_id="id_%s",
prefix=None,
initial=None,
error_class=ErrorList,
label_suffix=None,
empty_permitted=False,
field_order=None,
use_required_attribute=None,
renderer=None,
):
self.is_bound = data is not None or files is not None
self.data = MultiValueDict() if data is None else data
self.files = MultiValueDict() if files is None else files
self.auto_id = auto_id
if prefix is not None:
self.prefix = prefix
self.initial = initial or {}
self.error_class = error_class
# Translators: This is the default suffix added to form field labels
self.label_suffix = label_suffix if label_suffix is not None else _(":")
self.empty_permitted = empty_permitted
self._errors = None # Stores the errors after clean() has been called.
# The base_fields class attribute is the *class-wide* definition of
# fields. Because a particular *instance* of the class might want to
# alter self.fields, we create self.fields here by copying base_fields.
# Instances should always modify self.fields; they should not modify
# self.base_fields.
self.fields = copy.deepcopy(self.base_fields)
self._bound_fields_cache = {}
self.order_fields(self.field_order if field_order is None else field_order)
if use_required_attribute is not None:
self.use_required_attribute = use_required_attribute
if self.empty_permitted and self.use_required_attribute:
raise ValueError(
"The empty_permitted and use_required_attribute arguments may "
"not both be True."
)
# Initialize form renderer. Use a global default if not specified
# either as an argument or as self.default_renderer.
if renderer is None:
if self.default_renderer is None:
renderer = get_default_renderer()
else:
renderer = self.default_renderer
if isinstance(self.default_renderer, type):
renderer = renderer()
self.renderer = renderer
def order_fields(self, field_order):
"""
Rearrange the fields according to field_order.
field_order is a list of field names specifying the order. Append fields
not included in the list in the default order for backward compatibility
with subclasses not overriding field_order. If field_order is None,
keep all fields in the order defined in the class. Ignore unknown
fields in field_order to allow disabling fields in form subclasses
without redefining ordering.
"""
if field_order is None:
return
fields = {}
for key in field_order:
try:
fields[key] = self.fields.pop(key)
except KeyError: # ignore unknown fields
pass
fields.update(self.fields) # add remaining fields in original order
self.fields = fields
def __repr__(self):
if self._errors is None:
is_valid = "Unknown"
else:
is_valid = self.is_bound and not self._errors
return "<%(cls)s bound=%(bound)s, valid=%(valid)s, fields=(%(fields)s)>" % {
"cls": self.__class__.__name__,
"bound": self.is_bound,
"valid": is_valid,
"fields": ";".join(self.fields),
}
def _bound_items(self):
"""Yield (name, bf) pairs, where bf is a BoundField object."""
for name in self.fields:
yield name, self[name]
def __iter__(self):
"""Yield the form's fields as BoundField objects."""
for name in self.fields:
yield self[name]
def __getitem__(self, name):
"""Return a BoundField with the given name."""
try:
field = self.fields[name]
except KeyError:
raise KeyError(
"Key '%s' not found in '%s'. Choices are: %s."
% (
name,
self.__class__.__name__,
", ".join(sorted(self.fields)),
)
)
if name not in self._bound_fields_cache:
self._bound_fields_cache[name] = field.get_bound_field(self, name)
return self._bound_fields_cache[name]
@property
def errors(self):
"""Return an ErrorDict for the data provided for the form."""
if self._errors is None:
self.full_clean()
return self._errors
def is_valid(self):
"""Return True if the form has no errors, or False otherwise."""
return self.is_bound and not self.errors
def add_prefix(self, field_name):
"""
Return the field name with a prefix appended, if this Form has a
prefix set.
Subclasses may wish to override.
"""
return "%s-%s" % (self.prefix, field_name) if self.prefix else field_name
def add_initial_prefix(self, field_name):
"""Add an 'initial' prefix for checking dynamic initial values."""
return "initial-%s" % self.add_prefix(field_name)
def _widget_data_value(self, widget, html_name):
# value_from_datadict() gets the data from the data dictionaries.
# Each widget type knows how to retrieve its own data, because some
# widgets split data over several HTML fields.
return widget.value_from_datadict(self.data, self.files, html_name)
def _html_output(
self, normal_row, error_row, row_ender, help_text_html, errors_on_separate_row
):
"Output HTML. Used by as_table(), as_ul(), as_p()."
warnings.warn(
"django.forms.BaseForm._html_output() is deprecated. "
"Please use .render() and .get_context() instead.",
RemovedInDjango50Warning,
stacklevel=2,
)
# Errors that should be displayed above all fields.
top_errors = self.non_field_errors().copy()
output, hidden_fields = [], []
for name, bf in self._bound_items():
field = bf.field
html_class_attr = ""
bf_errors = self.error_class(bf.errors)
if bf.is_hidden:
if bf_errors:
top_errors.extend(
[
_("(Hidden field %(name)s) %(error)s")
% {"name": name, "error": str(e)}
for e in bf_errors
]
)
hidden_fields.append(str(bf))
else:
# Create a 'class="..."' attribute if the row should have any
# CSS classes applied.
css_classes = bf.css_classes()
if css_classes:
html_class_attr = ' class="%s"' % css_classes
if errors_on_separate_row and bf_errors:
output.append(error_row % str(bf_errors))
if bf.label:
label = conditional_escape(bf.label)
label = bf.label_tag(label) or ""
else:
label = ""
if field.help_text:
help_text = help_text_html % field.help_text
else:
help_text = ""
output.append(
normal_row
% {
"errors": bf_errors,
"label": label,
"field": bf,
"help_text": help_text,
"html_class_attr": html_class_attr,
"css_classes": css_classes,
"field_name": bf.html_name,
}
)
if top_errors:
output.insert(0, error_row % top_errors)
if hidden_fields: # Insert any hidden fields in the last row.
str_hidden = "".join(hidden_fields)
if output:
last_row = output[-1]
# Chop off the trailing row_ender (e.g. '</td></tr>') and
# insert the hidden fields.
if not last_row.endswith(row_ender):
# This can happen in the as_p() case (and possibly others
# that users write): if there are only top errors, we may
# not be able to conscript the last row for our purposes,
# so insert a new, empty row.
last_row = normal_row % {
"errors": "",
"label": "",
"field": "",
"help_text": "",
"html_class_attr": html_class_attr,
"css_classes": "",
"field_name": "",
}
output.append(last_row)
output[-1] = last_row[: -len(row_ender)] + str_hidden + row_ender
else:
# If there aren't any rows in the output, just append the
# hidden fields.
output.append(str_hidden)
return mark_safe("\n".join(output))
@property
def template_name(self):
return self.renderer.form_template_name
def get_context(self):
fields = []
hidden_fields = []
top_errors = self.non_field_errors().copy()
for name, bf in self._bound_items():
bf_errors = self.error_class(bf.errors, renderer=self.renderer)
if bf.is_hidden:
if bf_errors:
top_errors += [
_("(Hidden field %(name)s) %(error)s")
% {"name": name, "error": str(e)}
for e in bf_errors
]
hidden_fields.append(bf)
else:
errors_str = str(bf_errors)
# RemovedInDjango50Warning.
if not isinstance(errors_str, SafeString):
warnings.warn(
f"Returning a plain string from "
f"{self.error_class.__name__} is deprecated. Please "
f"customize via the template system instead.",
RemovedInDjango50Warning,
)
errors_str = mark_safe(errors_str)
fields.append((bf, errors_str))
return {
"form": self,
"fields": fields,
"hidden_fields": hidden_fields,
"errors": top_errors,
}
def non_field_errors(self):
"""
Return an ErrorList of errors that aren't associated with a particular
field -- i.e., from Form.clean(). Return an empty ErrorList if there
are none.
"""
return self.errors.get(
NON_FIELD_ERRORS,
self.error_class(error_class="nonfield", renderer=self.renderer),
)
def add_error(self, field, error):
"""
Update the content of `self._errors`.
The `field` argument is the name of the field to which the errors
should be added. If it's None, treat the errors as NON_FIELD_ERRORS.
The `error` argument can be a single error, a list of errors, or a
dictionary that maps field names to lists of errors. An "error" can be
either a simple string or an instance of ValidationError with its
message attribute set and a "list or dictionary" can be an actual
`list` or `dict` or an instance of ValidationError with its
`error_list` or `error_dict` attribute set.
If `error` is a dictionary, the `field` argument *must* be None and
errors will be added to the fields that correspond to the keys of the
dictionary.
"""
if not isinstance(error, ValidationError):
# Normalize to ValidationError and let its constructor
# do the hard work of making sense of the input.
error = ValidationError(error)
if hasattr(error, "error_dict"):
if field is not None:
raise TypeError(
"The argument `field` must be `None` when the `error` "
"argument contains errors for multiple fields."
)
else:
error = error.error_dict
else:
error = {field or NON_FIELD_ERRORS: error.error_list}
for field, error_list in error.items():
if field not in self.errors:
if field != NON_FIELD_ERRORS and field not in self.fields:
raise ValueError(
"'%s' has no field named '%s'."
% (self.__class__.__name__, field)
)
if field == NON_FIELD_ERRORS:
self._errors[field] = self.error_class(
error_class="nonfield", renderer=self.renderer
)
else:
self._errors[field] = self.error_class(renderer=self.renderer)
self._errors[field].extend(error_list)
if field in self.cleaned_data:
del self.cleaned_data[field]
def has_error(self, field, code=None):
return field in self.errors and (
code is None
or any(error.code == code for error in self.errors.as_data()[field])
)
def full_clean(self):
"""
Clean all of self.data and populate self._errors and self.cleaned_data.
"""
self._errors = ErrorDict()
if not self.is_bound: # Stop further processing.
return
self.cleaned_data = {}
# If the form is permitted to be empty, and none of the form data has
# changed from the initial data, short circuit any validation.
if self.empty_permitted and not self.has_changed():
return
self._clean_fields()
self._clean_form()
self._post_clean()
def _clean_fields(self):
for name, bf in self._bound_items():
field = bf.field
value = bf.initial if field.disabled else bf.data
try:
if isinstance(field, FileField):
value = field.clean(value, bf.initial)
else:
value = field.clean(value)
self.cleaned_data[name] = value
if hasattr(self, "clean_%s" % name):
value = getattr(self, "clean_%s" % name)()
self.cleaned_data[name] = value
except ValidationError as e:
self.add_error(name, e)
def _clean_form(self):
try:
cleaned_data = self.clean()
except ValidationError as e:
self.add_error(None, e)
else:
if cleaned_data is not None:
self.cleaned_data = cleaned_data
def _post_clean(self):
"""
An internal hook for performing additional cleaning after form cleaning
is complete. Used for model validation in model forms.
"""
pass
def clean(self):
"""
Hook for doing any extra form-wide cleaning after Field.clean() has been
called on every field. Any ValidationError raised by this method will
not be associated with a particular field; it will have a special-case
association with the field named '__all__'.
"""
return self.cleaned_data
def has_changed(self):
"""Return True if data differs from initial."""
return bool(self.changed_data)
@cached_property
def changed_data(self):
return [name for name, bf in self._bound_items() if bf._has_changed()]
@property
def media(self):
"""Return all media required to render the widgets on this form."""
media = Media()
for field in self.fields.values():
media += field.widget.media
return media
def is_multipart(self):
"""
Return True if the form needs to be multipart-encoded, i.e. it has
FileInput, or False otherwise.
"""
return any(field.widget.needs_multipart_form for field in self.fields.values())
def hidden_fields(self):
"""
Return a list of all the BoundField objects that are hidden fields.
Useful for manual form layout in templates.
"""
return [field for field in self if field.is_hidden]
def visible_fields(self):
"""
Return a list of BoundField objects that aren't hidden fields.
The opposite of the hidden_fields() method.
"""
return [field for field in self if not field.is_hidden]
def get_initial_for_field(self, field, field_name):
"""
Return initial data for field on form. Use initial data from the form
or the field, in that order. Evaluate callable values.
"""
value = self.initial.get(field_name, field.initial)
if callable(value):
value = value()
# If this is an auto-generated default date, nix the microseconds
# for standardized handling. See #22502.
if (
isinstance(value, (datetime.datetime, datetime.time))
and not field.widget.supports_microseconds
):
value = value.replace(microsecond=0)
return value
class Form(BaseForm, metaclass=DeclarativeFieldsMetaclass):
"A collection of Fields, plus their associated data."
# This is a separate class from BaseForm in order to abstract the way
# self.fields is specified. This class (Form) is the one that does the
# fancy metaclass stuff purely for the semantic sugar -- it allows one
# to define a form using declarative syntax.
# BaseForm itself has no way of designating self.fields.
|
castiel248/Convert
|
Lib/site-packages/django/forms/forms.py
|
Python
|
mit
| 20,512 |
from django.core.exceptions import ValidationError
from django.forms import Form
from django.forms.fields import BooleanField, IntegerField
from django.forms.renderers import get_default_renderer
from django.forms.utils import ErrorList, RenderableFormMixin
from django.forms.widgets import CheckboxInput, HiddenInput, NumberInput
from django.utils.functional import cached_property
from django.utils.translation import gettext_lazy as _
from django.utils.translation import ngettext_lazy
__all__ = ("BaseFormSet", "formset_factory", "all_valid")
# special field names
TOTAL_FORM_COUNT = "TOTAL_FORMS"
INITIAL_FORM_COUNT = "INITIAL_FORMS"
MIN_NUM_FORM_COUNT = "MIN_NUM_FORMS"
MAX_NUM_FORM_COUNT = "MAX_NUM_FORMS"
ORDERING_FIELD_NAME = "ORDER"
DELETION_FIELD_NAME = "DELETE"
# default minimum number of forms in a formset
DEFAULT_MIN_NUM = 0
# default maximum number of forms in a formset, to prevent memory exhaustion
DEFAULT_MAX_NUM = 1000
class ManagementForm(Form):
"""
Keep track of how many form instances are displayed on the page. If adding
new forms via JavaScript, you should increment the count field of this form
as well.
"""
template_name = "django/forms/div.html" # RemovedInDjango50Warning.
TOTAL_FORMS = IntegerField(widget=HiddenInput)
INITIAL_FORMS = IntegerField(widget=HiddenInput)
# MIN_NUM_FORM_COUNT and MAX_NUM_FORM_COUNT are output with the rest of the
# management form, but only for the convenience of client-side code. The
# POST value of them returned from the client is not checked.
MIN_NUM_FORMS = IntegerField(required=False, widget=HiddenInput)
MAX_NUM_FORMS = IntegerField(required=False, widget=HiddenInput)
def clean(self):
cleaned_data = super().clean()
# When the management form is invalid, we don't know how many forms
# were submitted.
cleaned_data.setdefault(TOTAL_FORM_COUNT, 0)
cleaned_data.setdefault(INITIAL_FORM_COUNT, 0)
return cleaned_data
class BaseFormSet(RenderableFormMixin):
"""
A collection of instances of the same Form class.
"""
deletion_widget = CheckboxInput
ordering_widget = NumberInput
default_error_messages = {
"missing_management_form": _(
"ManagementForm data is missing or has been tampered with. Missing fields: "
"%(field_names)s. You may need to file a bug report if the issue persists."
),
"too_many_forms": ngettext_lazy(
"Please submit at most %(num)d form.",
"Please submit at most %(num)d forms.",
"num",
),
"too_few_forms": ngettext_lazy(
"Please submit at least %(num)d form.",
"Please submit at least %(num)d forms.",
"num",
),
}
template_name_div = "django/forms/formsets/div.html"
template_name_p = "django/forms/formsets/p.html"
template_name_table = "django/forms/formsets/table.html"
template_name_ul = "django/forms/formsets/ul.html"
def __init__(
self,
data=None,
files=None,
auto_id="id_%s",
prefix=None,
initial=None,
error_class=ErrorList,
form_kwargs=None,
error_messages=None,
):
self.is_bound = data is not None or files is not None
self.prefix = prefix or self.get_default_prefix()
self.auto_id = auto_id
self.data = data or {}
self.files = files or {}
self.initial = initial
self.form_kwargs = form_kwargs or {}
self.error_class = error_class
self._errors = None
self._non_form_errors = None
messages = {}
for cls in reversed(type(self).__mro__):
messages.update(getattr(cls, "default_error_messages", {}))
if error_messages is not None:
messages.update(error_messages)
self.error_messages = messages
def __iter__(self):
"""Yield the forms in the order they should be rendered."""
return iter(self.forms)
def __getitem__(self, index):
"""Return the form at the given index, based on the rendering order."""
return self.forms[index]
def __len__(self):
return len(self.forms)
def __bool__(self):
"""
Return True since all formsets have a management form which is not
included in the length.
"""
return True
def __repr__(self):
if self._errors is None:
is_valid = "Unknown"
else:
is_valid = (
self.is_bound
and not self._non_form_errors
and not any(form_errors for form_errors in self._errors)
)
return "<%s: bound=%s valid=%s total_forms=%s>" % (
self.__class__.__qualname__,
self.is_bound,
is_valid,
self.total_form_count(),
)
@cached_property
def management_form(self):
"""Return the ManagementForm instance for this FormSet."""
if self.is_bound:
form = ManagementForm(
self.data,
auto_id=self.auto_id,
prefix=self.prefix,
renderer=self.renderer,
)
form.full_clean()
else:
form = ManagementForm(
auto_id=self.auto_id,
prefix=self.prefix,
initial={
TOTAL_FORM_COUNT: self.total_form_count(),
INITIAL_FORM_COUNT: self.initial_form_count(),
MIN_NUM_FORM_COUNT: self.min_num,
MAX_NUM_FORM_COUNT: self.max_num,
},
renderer=self.renderer,
)
return form
def total_form_count(self):
"""Return the total number of forms in this FormSet."""
if self.is_bound:
# return absolute_max if it is lower than the actual total form
# count in the data; this is DoS protection to prevent clients
# from forcing the server to instantiate arbitrary numbers of
# forms
return min(
self.management_form.cleaned_data[TOTAL_FORM_COUNT], self.absolute_max
)
else:
initial_forms = self.initial_form_count()
total_forms = max(initial_forms, self.min_num) + self.extra
# Allow all existing related objects/inlines to be displayed,
# but don't allow extra beyond max_num.
if initial_forms > self.max_num >= 0:
total_forms = initial_forms
elif total_forms > self.max_num >= 0:
total_forms = self.max_num
return total_forms
def initial_form_count(self):
"""Return the number of forms that are required in this FormSet."""
if self.is_bound:
return self.management_form.cleaned_data[INITIAL_FORM_COUNT]
else:
# Use the length of the initial data if it's there, 0 otherwise.
initial_forms = len(self.initial) if self.initial else 0
return initial_forms
@cached_property
def forms(self):
"""Instantiate forms at first property access."""
# DoS protection is included in total_form_count()
return [
self._construct_form(i, **self.get_form_kwargs(i))
for i in range(self.total_form_count())
]
def get_form_kwargs(self, index):
"""
Return additional keyword arguments for each individual formset form.
index will be None if the form being constructed is a new empty
form.
"""
return self.form_kwargs.copy()
def _construct_form(self, i, **kwargs):
"""Instantiate and return the i-th form instance in a formset."""
defaults = {
"auto_id": self.auto_id,
"prefix": self.add_prefix(i),
"error_class": self.error_class,
# Don't render the HTML 'required' attribute as it may cause
# incorrect validation for extra, optional, and deleted
# forms in the formset.
"use_required_attribute": False,
"renderer": self.renderer,
}
if self.is_bound:
defaults["data"] = self.data
defaults["files"] = self.files
if self.initial and "initial" not in kwargs:
try:
defaults["initial"] = self.initial[i]
except IndexError:
pass
# Allow extra forms to be empty, unless they're part of
# the minimum forms.
if i >= self.initial_form_count() and i >= self.min_num:
defaults["empty_permitted"] = True
defaults.update(kwargs)
form = self.form(**defaults)
self.add_fields(form, i)
return form
@property
def initial_forms(self):
"""Return a list of all the initial forms in this formset."""
return self.forms[: self.initial_form_count()]
@property
def extra_forms(self):
"""Return a list of all the extra forms in this formset."""
return self.forms[self.initial_form_count() :]
@property
def empty_form(self):
form_kwargs = {
**self.get_form_kwargs(None),
"auto_id": self.auto_id,
"prefix": self.add_prefix("__prefix__"),
"empty_permitted": True,
"use_required_attribute": False,
"renderer": self.renderer,
}
form = self.form(**form_kwargs)
self.add_fields(form, None)
return form
@property
def cleaned_data(self):
"""
Return a list of form.cleaned_data dicts for every form in self.forms.
"""
if not self.is_valid():
raise AttributeError(
"'%s' object has no attribute 'cleaned_data'" % self.__class__.__name__
)
return [form.cleaned_data for form in self.forms]
@property
def deleted_forms(self):
"""Return a list of forms that have been marked for deletion."""
if not self.is_valid() or not self.can_delete:
return []
# construct _deleted_form_indexes which is just a list of form indexes
# that have had their deletion widget set to True
if not hasattr(self, "_deleted_form_indexes"):
self._deleted_form_indexes = []
for i, form in enumerate(self.forms):
# if this is an extra form and hasn't changed, don't consider it
if i >= self.initial_form_count() and not form.has_changed():
continue
if self._should_delete_form(form):
self._deleted_form_indexes.append(i)
return [self.forms[i] for i in self._deleted_form_indexes]
@property
def ordered_forms(self):
"""
Return a list of form in the order specified by the incoming data.
Raise an AttributeError if ordering is not allowed.
"""
if not self.is_valid() or not self.can_order:
raise AttributeError(
"'%s' object has no attribute 'ordered_forms'" % self.__class__.__name__
)
# Construct _ordering, which is a list of (form_index, order_field_value)
# tuples. After constructing this list, we'll sort it by order_field_value
# so we have a way to get to the form indexes in the order specified
# by the form data.
if not hasattr(self, "_ordering"):
self._ordering = []
for i, form in enumerate(self.forms):
# if this is an extra form and hasn't changed, don't consider it
if i >= self.initial_form_count() and not form.has_changed():
continue
# don't add data marked for deletion to self.ordered_data
if self.can_delete and self._should_delete_form(form):
continue
self._ordering.append((i, form.cleaned_data[ORDERING_FIELD_NAME]))
# After we're done populating self._ordering, sort it.
# A sort function to order things numerically ascending, but
# None should be sorted below anything else. Allowing None as
# a comparison value makes it so we can leave ordering fields
# blank.
def compare_ordering_key(k):
if k[1] is None:
return (1, 0) # +infinity, larger than any number
return (0, k[1])
self._ordering.sort(key=compare_ordering_key)
# Return a list of form.cleaned_data dicts in the order specified by
# the form data.
return [self.forms[i[0]] for i in self._ordering]
@classmethod
def get_default_prefix(cls):
return "form"
@classmethod
def get_deletion_widget(cls):
return cls.deletion_widget
@classmethod
def get_ordering_widget(cls):
return cls.ordering_widget
def non_form_errors(self):
"""
Return an ErrorList of errors that aren't associated with a particular
form -- i.e., from formset.clean(). Return an empty ErrorList if there
are none.
"""
if self._non_form_errors is None:
self.full_clean()
return self._non_form_errors
@property
def errors(self):
"""Return a list of form.errors for every form in self.forms."""
if self._errors is None:
self.full_clean()
return self._errors
def total_error_count(self):
"""Return the number of errors across all forms in the formset."""
return len(self.non_form_errors()) + sum(
len(form_errors) for form_errors in self.errors
)
def _should_delete_form(self, form):
"""Return whether or not the form was marked for deletion."""
return form.cleaned_data.get(DELETION_FIELD_NAME, False)
def is_valid(self):
"""Return True if every form in self.forms is valid."""
if not self.is_bound:
return False
# Accessing errors triggers a full clean the first time only.
self.errors
# List comprehension ensures is_valid() is called for all forms.
# Forms due to be deleted shouldn't cause the formset to be invalid.
forms_valid = all(
[
form.is_valid()
for form in self.forms
if not (self.can_delete and self._should_delete_form(form))
]
)
return forms_valid and not self.non_form_errors()
def full_clean(self):
"""
Clean all of self.data and populate self._errors and
self._non_form_errors.
"""
self._errors = []
self._non_form_errors = self.error_class(
error_class="nonform", renderer=self.renderer
)
empty_forms_count = 0
if not self.is_bound: # Stop further processing.
return
if not self.management_form.is_valid():
error = ValidationError(
self.error_messages["missing_management_form"],
params={
"field_names": ", ".join(
self.management_form.add_prefix(field_name)
for field_name in self.management_form.errors
),
},
code="missing_management_form",
)
self._non_form_errors.append(error)
for i, form in enumerate(self.forms):
# Empty forms are unchanged forms beyond those with initial data.
if not form.has_changed() and i >= self.initial_form_count():
empty_forms_count += 1
# Accessing errors calls full_clean() if necessary.
# _should_delete_form() requires cleaned_data.
form_errors = form.errors
if self.can_delete and self._should_delete_form(form):
continue
self._errors.append(form_errors)
try:
if (
self.validate_max
and self.total_form_count() - len(self.deleted_forms) > self.max_num
) or self.management_form.cleaned_data[
TOTAL_FORM_COUNT
] > self.absolute_max:
raise ValidationError(
self.error_messages["too_many_forms"] % {"num": self.max_num},
code="too_many_forms",
)
if (
self.validate_min
and self.total_form_count()
- len(self.deleted_forms)
- empty_forms_count
< self.min_num
):
raise ValidationError(
self.error_messages["too_few_forms"] % {"num": self.min_num},
code="too_few_forms",
)
# Give self.clean() a chance to do cross-form validation.
self.clean()
except ValidationError as e:
self._non_form_errors = self.error_class(
e.error_list,
error_class="nonform",
renderer=self.renderer,
)
def clean(self):
"""
Hook for doing any extra formset-wide cleaning after Form.clean() has
been called on every form. Any ValidationError raised by this method
will not be associated with a particular form; it will be accessible
via formset.non_form_errors()
"""
pass
def has_changed(self):
"""Return True if data in any form differs from initial."""
return any(form.has_changed() for form in self)
def add_fields(self, form, index):
"""A hook for adding extra fields on to each form instance."""
initial_form_count = self.initial_form_count()
if self.can_order:
# Only pre-fill the ordering field for initial forms.
if index is not None and index < initial_form_count:
form.fields[ORDERING_FIELD_NAME] = IntegerField(
label=_("Order"),
initial=index + 1,
required=False,
widget=self.get_ordering_widget(),
)
else:
form.fields[ORDERING_FIELD_NAME] = IntegerField(
label=_("Order"),
required=False,
widget=self.get_ordering_widget(),
)
if self.can_delete and (
self.can_delete_extra or (index is not None and index < initial_form_count)
):
form.fields[DELETION_FIELD_NAME] = BooleanField(
label=_("Delete"),
required=False,
widget=self.get_deletion_widget(),
)
def add_prefix(self, index):
return "%s-%s" % (self.prefix, index)
def is_multipart(self):
"""
Return True if the formset needs to be multipart, i.e. it
has FileInput, or False otherwise.
"""
if self.forms:
return self.forms[0].is_multipart()
else:
return self.empty_form.is_multipart()
@property
def media(self):
# All the forms on a FormSet are the same, so you only need to
# interrogate the first form for media.
if self.forms:
return self.forms[0].media
else:
return self.empty_form.media
@property
def template_name(self):
return self.renderer.formset_template_name
def get_context(self):
return {"formset": self}
def formset_factory(
form,
formset=BaseFormSet,
extra=1,
can_order=False,
can_delete=False,
max_num=None,
validate_max=False,
min_num=None,
validate_min=False,
absolute_max=None,
can_delete_extra=True,
renderer=None,
):
"""Return a FormSet for the given form class."""
if min_num is None:
min_num = DEFAULT_MIN_NUM
if max_num is None:
max_num = DEFAULT_MAX_NUM
# absolute_max is a hard limit on forms instantiated, to prevent
# memory-exhaustion attacks. Default to max_num + DEFAULT_MAX_NUM
# (which is 2 * DEFAULT_MAX_NUM if max_num is None in the first place).
if absolute_max is None:
absolute_max = max_num + DEFAULT_MAX_NUM
if max_num > absolute_max:
raise ValueError("'absolute_max' must be greater or equal to 'max_num'.")
attrs = {
"form": form,
"extra": extra,
"can_order": can_order,
"can_delete": can_delete,
"can_delete_extra": can_delete_extra,
"min_num": min_num,
"max_num": max_num,
"absolute_max": absolute_max,
"validate_min": validate_min,
"validate_max": validate_max,
"renderer": renderer or get_default_renderer(),
}
return type(form.__name__ + "FormSet", (formset,), attrs)
def all_valid(formsets):
"""Validate every formset and return True if all are valid."""
# List comprehension ensures is_valid() is called for all formsets.
return all([formset.is_valid() for formset in formsets])
|
castiel248/Convert
|
Lib/site-packages/django/forms/formsets.py
|
Python
|
mit
| 21,167 |
{% for name, value in attrs.items() %}{% if value is not sameas False %} {{ name }}{% if value is not sameas True %}="{{ value }}"{% endif %}{% endif %}{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/attrs.html
|
HTML
|
mit
| 165 |
{% include "django/forms/table.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/default.html
|
HTML
|
mit
| 40 |
{{ errors }}
{% if errors and not fields %}
<div>{% for field in hidden_fields %}{{ field }}{% endfor %}</div>
{% endif %}
{% for field, errors in fields %}
<div{% set classes = field.css_classes() %}{% if classes %} class="{{ classes }}"{% endif %}>
{% if field.use_fieldset %}
<fieldset>
{% if field.label %}{{ field.legend_tag() }}{% endif %}
{% else %}
{% if field.label %}{{ field.label_tag() }}{% endif %}
{% endif %}
{% if field.help_text %}<div class="helptext">{{ field.help_text|safe }}</div>{% endif %}
{{ errors }}
{{ field }}
{% if field.use_fieldset %}</fieldset>{% endif %}
{% if loop.last %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
</div>
{% endfor %}
{% if not fields and not errors %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/div.html
|
HTML
|
mit
| 865 |
{% include "django/forms/errors/dict/ul.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/errors/dict/default.html
|
HTML
|
mit
| 49 |
{% for field, errors in errors %}* {{ field }}
{% for error in errors %} * {{ error }}
{% endfor %}{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/errors/dict/text.txt
|
Text
|
mit
| 113 |
{% if errors %}<ul class="{{ error_class }}">{% for field, error in errors %}<li>{{ field }}{{ error }}</li>{% endfor %}</ul>{% endif %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/errors/dict/ul.html
|
HTML
|
mit
| 137 |
{% include "django/forms/errors/list/ul.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/errors/list/default.html
|
HTML
|
mit
| 49 |
{% for error in errors %}* {{ error }}
{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/errors/list/text.txt
|
Text
|
mit
| 52 |
{% if errors %}<ul class="{{ error_class }}">{% for error in errors %}<li>{{ error }}</li>{% endfor %}</ul>{% endif %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/errors/list/ul.html
|
HTML
|
mit
| 119 |
{{ formset.management_form }}{% for form in formset %}{{ form }}{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/formsets/default.html
|
HTML
|
mit
| 77 |
{{ formset.management_form }}{% for form in formset %}{{ form.as_div() }}{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/formsets/div.html
|
HTML
|
mit
| 86 |
{{ formset.management_form }}{% for form in formset %}{{ form.as_p() }}{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/formsets/p.html
|
HTML
|
mit
| 84 |
{{ formset.management_form }}{% for form in formset %}{{ form.as_table() }}{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/formsets/table.html
|
HTML
|
mit
| 88 |
{{ formset.management_form }}{% for form in formset %}{{ form.as_ul() }}{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/formsets/ul.html
|
HTML
|
mit
| 85 |
{% if use_tag %}<{{ tag }}{% if attrs %}{% include 'django/forms/attrs.html' %}{% endif %}>{{ label }}</{{ tag }}>{% else %}{{ label }}{% endif %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/label.html
|
HTML
|
mit
| 147 |
{{ errors }}
{% if errors and not fields %}
<p>{% for field in hidden_fields %}{{ field }}{% endfor %}</p>
{% endif %}
{% for field, errors in fields %}
{{ errors }}
<p{% set classes = field.css_classes() %}{% if classes %} class="{{ classes }}"{% endif %}>
{% if field.label %}{{ field.label_tag() }}{% endif %}
{{ field }}
{% if field.help_text %}
<span class="helptext">{{ field.help_text|safe }}</span>
{% endif %}
{% if loop.last %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
</p>
{% endfor %}
{% if not fields and not errors %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/p.html
|
HTML
|
mit
| 673 |
{% if errors %}
<tr>
<td colspan="2">
{{ errors }}
{% if not fields %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
</td>
</tr>
{% endif %}
{% for field, errors in fields %}
<tr{% set classes = field.css_classes() %}{% if classes %} class="{{ classes }}"{% endif %}>
<th>{% if field.label %}{{ field.label_tag() }}{% endif %}</th>
<td>
{{ errors }}
{{ field }}
{% if field.help_text %}
<br>
<span class="helptext">{{ field.help_text|safe }}</span>
{% endif %}
{% if loop.last %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
</td>
</tr>
{% endfor %}
{% if not fields and not errors %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/table.html
|
HTML
|
mit
| 814 |
{% if errors %}
<li>
{{ errors }}
{% if not fields %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
</li>
{% endif %}
{% for field, errors in fields %}
<li{% set classes = field.css_classes() %}{% if classes %} class="{{ classes }}"{% endif %}>
{{ errors }}
{% if field.label %}{{ field.label_tag() }}{% endif %}
{{ field }}
{% if field.help_text %}
<span class="helptext">{{ field.help_text|safe }}</span>
{% endif %}
{% if loop.last %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
</li>
{% endfor %}
{% if not fields and not errors %}
{% for field in hidden_fields %}{{ field }}{% endfor %}
{% endif %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/ul.html
|
HTML
|
mit
| 712 |
{% for name, value in widget.attrs.items() %}{% if value is not sameas False %} {{ name }}{% if value is not sameas True %}="{{ value }}"{% endif %}{% endif %}{% endfor %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/attrs.html
|
HTML
|
mit
| 172 |
{% include "django/forms/widgets/input.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/checkbox.html
|
HTML
|
mit
| 48 |
{% include "django/forms/widgets/input_option.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/checkbox_option.html
|
HTML
|
mit
| 55 |
{% include "django/forms/widgets/multiple_input.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/checkbox_select.html
|
HTML
|
mit
| 57 |
{% if widget.is_initial %}{{ widget.initial_text }}: <a href="{{ widget.value.url }}">{{ widget.value }}</a>{% if not widget.required %}
<input type="checkbox" name="{{ widget.checkbox_name }}" id="{{ widget.checkbox_id }}"{% if widget.attrs.disabled %} disabled{% endif %}>
<label for="{{ widget.checkbox_id }}">{{ widget.clear_checkbox_label }}</label>{% endif %}<br>
{{ widget.input_text }}:{% endif %}
<input type="{{ widget.type }}" name="{{ widget.name }}"{% include "django/forms/widgets/attrs.html" %}>
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/clearable_file_input.html
|
HTML
|
mit
| 511 |
{% include "django/forms/widgets/input.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/date.html
|
HTML
|
mit
| 48 |
{% include "django/forms/widgets/input.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/datetime.html
|
HTML
|
mit
| 48 |
{% include "django/forms/widgets/input.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/email.html
|
HTML
|
mit
| 48 |
{% include "django/forms/widgets/input.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/file.html
|
HTML
|
mit
| 48 |
{% include "django/forms/widgets/input.html" %}
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/hidden.html
|
HTML
|
mit
| 48 |
<input type="{{ widget.type }}" name="{{ widget.name }}"{% if widget.value != None %} value="{{ widget.value }}"{% endif %}{% include "django/forms/widgets/attrs.html" %}>
|
castiel248/Convert
|
Lib/site-packages/django/forms/jinja2/django/forms/widgets/input.html
|
HTML
|
mit
| 172 |
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