Source code
import copy
import operator
import warnings
from contextlib import nullcontext
from functools import partial, reduce
from itertools import chain, islice
from weakref import ref as weak_ref
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, Max, sql
from django.db.models.constants import LOOKUP_SEP, OnConflict
from django.db.models.deletion import Collector
from django.db.models.expressions import ( Case, Col, ColPairs, DatabaseDefault, F,
OrderBy,
Value,
When, )
from django.db.models.fetch_modes import FETCH_ONE
from django.db.models.functions import Cast, Trunc
from django.db.models.query_utils import PROHIBITED_FILTER_KWARGS, FilteredRelation, Q
from django.db.models.sql.constants import GET_ITERATOR_CHUNK_SIZE, ROW_COUNT
from django.db.models.utils import (
AltersData,
create_namedtuple_class,
resolve_callables,
)
from django.utils import timezone
from django.utils.deprecation import ( RemovedInDjango70Warning,
RemovedInDjango71Warning, warn_about_external_use, )
from django.utils.functional import cached_property
from django.utils.inspect import func_accepts_kwargs, func_supports_parameter
from django.utils.warnings import django_file_prefixes
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._fetch_mode = DEFAULT_FETCH_MODE
self._fields = None
self._defer_next_filter = False
self._deferred_filter = None
self._cloning_enabled = True
@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:
raise ValueError(
"chunk_size must be provided when using QuerySet.iterator() after " "prefetch_related()." )
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=None):
"""
An asynchronous iterator over the results from applying this QuerySet
to the database.
"""
if chunk_size is None:
if self._prefetch_related_lookups:
# RemovedInDjango71Warning: Replace the warning with:
# raise ValueError(
# "chunk_size must be provided when using "
# "QuerySet.aiterator() after prefetch_related()."
# )
warnings.warn(
"Using QuerySet.aiterator() after prefetch_related() without "
"providing a chunk_size is deprecated and will raise a "
"ValueError in Django 7.1.",
category=RemovedInDjango71Warning, skip_file_prefixes=django_file_prefixes(),
)
# RemovedInDjango71Warning: When the deprecation ends, remove.
chunk_size = 2000
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"
)
iterable = self._iterable_class( self, chunked_fetch=use_chunked_fetch, chunk_size=chunk_size or 2000, )
if self._prefetch_related_lookups:
results = []
async for item in iterable:
results.append(item)
if len(results) >= chunk_size:
await aprefetch_related_objects(
results, *self._prefetch_related_lookups
)
for result in results:
yield result
results.clear()
if results:
await aprefetch_related_objects( results, *self._prefetch_related_lookups
)
for result in results:
yield result
else:
async for item in iterable:
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.
"""
reverse_one_to_one_fields = frozenset(kwargs).intersection( self.model._meta._reverse_one_to_one_field_names )
if reverse_one_to_one_fields:
raise ValueError(
"The following fields do not exist in this model: %s" % ", ".join(reverse_one_to_one_fields) )
obj = self.model(**kwargs)
self._for_write = True
obj.save(force_insert=True, using=self.db)
obj._state.fetch_mode = self._fetch_mode
return obj
create.alters_data = True
async def acreate(self, **kwargs):
return await sync_to_async(self.create)(**kwargs)
acreate.alters_data = True
def _prepare_for_bulk_create(self, objs):
objs_with_pk, objs_without_pk = [], []
for obj in objs:
obj._prepare_related_fields_for_save(operation_name="bulk_create")
if isinstance(obj.pk, DatabaseDefault):
objs_without_pk.append(obj)
elif obj._is_pk_set():
objs_with_pk.append(obj)
else:
obj.pk = obj._meta.pk.get_pk_value_on_save(obj)
if obj._is_pk_set():
objs_with_pk.append(obj)
else:
objs_without_pk.append(obj)
return objs_with_pk, objs_without_pk
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 for f in update_fields):
raise ValueError(
"bulk_create() can only be used with concrete fields in "
"update_fields."
)
if any(f in self.model._meta.pk_fields 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 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.all_parents:
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 = [f for f in opts.concrete_fields if not f.generated]
objs = list(objs)
objs_with_pk, objs_without_pk = self._prepare_for_bulk_create(objs)
if objs_with_pk and objs_without_pk:
context = transaction.atomic(using=self.db, savepoint=False)
else:
context = nullcontext()
with context:
self._handle_order_with_respect_to(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):
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
def _handle_order_with_respect_to(self, objs):
if objs and (order_wrt := self.model._meta.order_with_respect_to):
get_filter_kwargs_for_object = order_wrt.get_filter_kwargs_for_object
attnames = list(get_filter_kwargs_for_object(objs[0]))
group_keys = set()
obj_groups = []
for obj in objs:
group_key = tuple(get_filter_kwargs_for_object(obj).values())
group_keys.add(group_key)
obj_groups.append((obj, group_key))
filters = [ Q.create(list(zip(attnames, group_key))) for group_key in group_keys
]
next_orders = (
self.model._base_manager.using(self.db) .filter(reduce(operator.or_, filters))
.values_list(*attnames)
.annotate(_order__max=Max("_order") + 1)
)
# Create mapping of group values to max order.
group_next_orders = dict.fromkeys(group_keys, 0)
group_next_orders.update( (tuple(group_key), next_order) for *group_key, next_order in next_orders
)
# Assign _order values to new objects.
for obj, group_key in obj_groups:
if getattr(obj, "_order", None) is None:
group_next_order = group_next_orders[group_key]
obj._order = group_next_order
group_next_orders[group_key] += 1
bulk_create.alters_data = True
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, )
abulk_create.alters_data = True
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 not all(obj._is_pk_set() for obj in objs):
raise ValueError("All bulk_update() objects must have a primary key set.")
opts = self.model._meta
fields = [opts.get_field(name) for name in fields]
if any(not f.concrete for f in fields):
raise ValueError("bulk_update() can only be used with concrete fields.")
all_pk_fields = set(opts.pk_fields)
for parent in opts.all_parents:
all_pk_fields.update(parent._meta.pk_fields)
if any(f in all_pk_fields 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(
[opts.pk, opts.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
get_or_create.alters_data = True
async def aget_or_create(self, defaults=None, **kwargs):
return await sync_to_async(self.get_or_create)( defaults=defaults,
**kwargs, )
aget_or_create.alters_data = True
def update_or_create(self, defaults=None, create_defaults=None, **kwargs):
"""
Look up an object with the given kwargs, updating one with defaults
if it exists, otherwise create a new one. Optionally, an object can
be created with different values than defaults by using
create_defaults.
Return a tuple (object, created), where created is a boolean
specifying whether an object was created.
"""
update_defaults = defaults or {}
if create_defaults is None:
create_defaults = update_defaults
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(
create_defaults, **kwargs )
if created:
return obj, created
for k, v in resolve_callables(update_defaults):
setattr(obj, k, v)
update_fields = set(update_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.
pk_fields = self.model._meta.pk_fields
for field in self.model._meta.local_concrete_fields:
if not (
field in pk_fields 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
update_or_create.alters_data = True
async def aupdate_or_create(self, defaults=None, create_defaults=None, **kwargs):
return await sync_to_async(self.update_or_create)( defaults=defaults,
create_defaults=create_defaults,
**kwargs,
)
aupdate_or_create.alters_data = True
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 or not self.query.default_ordering:
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 or not self.query.default_ordering:
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().")
if id_list is not None and not id_list:
return {}
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
)
qs = self
def get_obj(obj):
return obj
if issubclass(self._iterable_class, ModelIterable):
# Raise an AttributeError if field_name is deferred.
get_key = operator.attrgetter(field_name)
elif issubclass(self._iterable_class, ValuesIterable):
if field_name not in self.query.values_select:
qs = qs.values(field_name, *self.query.values_select)
def get_obj(obj): # noqa: F811
# We can safely mutate the dictionaries returned by
# ValuesIterable here, since they are limited to the scope
# of this function, and get_key runs before get_obj.
del obj[field_name]
return obj
get_key = operator.itemgetter(field_name)
elif issubclass(self._iterable_class, ValuesListIterable):
try:
field_index = self.query.values_select.index(field_name)
except ValueError:
# field_name is missing from values_select, so add it.
field_index = 0
if issubclass(self._iterable_class, NamedValuesListIterable):
kwargs = {"named": True}
else:
kwargs = {}
get_obj = operator.itemgetter(slice(1, None))
qs = qs.values_list(field_name, *self.query.values_select, **kwargs)
get_key = operator.itemgetter(field_index)
elif issubclass(self._iterable_class, FlatValuesListIterable):
if self.query.values_select == (field_name,):
# Mapping field_name to itself.
get_key = get_obj
else:
# Transform it back into a non-flat values_list().
qs = qs.values_list(field_name, *self.query.values_select)
get_key = operator.itemgetter(0)
get_obj = operator.itemgetter(1)
else:
raise TypeError( f"in_bulk() cannot be used with {self._iterable_class.__name__}." )
if id_list is not None:
filter_key = "{}__in".format(field_name)
id_list = tuple(id_list)
batch_size = connections[self.db].ops.bulk_batch_size([opts.pk], 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):
results = ()
for offset in range(0, len(id_list), batch_size):
batch = id_list[offset : offset + batch_size]
results += tuple(qs.filter(**{filter_key: batch}))
qs = results
else:
qs = qs.filter(**{filter_key: id_list})
else:
qs = qs._chain()
return {get_key(obj): get_obj(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_fields:
raise TypeError("Cannot call delete() after .distinct(*fields).")
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)
num_deleted, num_deleted_per_model = collector.delete()
# Clear the result cache, in case this QuerySet gets reused.
self._result_cache = None
return num_deleted, num_deleted_per_model
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
return query.get_compiler(using).execute_sql(ROW_COUNT)
_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.")
if self.query.distinct_fields:
raise TypeError("Cannot call update() after .distinct(*fields).")
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:
alias = col
descending = False
if isinstance(alias, str) and alias.startswith("-"):
alias = alias.removeprefix("-")
descending = True
if annotation := query.annotations.get(alias):
if getattr(annotation, "contains_aggregate", False):
raise exceptions.FieldError(
f"Cannot update when ordering by an aggregate: {annotation}" )
if descending:
annotation = annotation.desc()
new_order_by.append(annotation)
else:
new_order_by.append(col)
query.order_by = tuple(new_order_by)
# Clear SELECT clause as all annotation references were inlined by
# add_update_values() already.
query.clear_select_clause()
with transaction.mark_for_rollback_on_error(using=self.db):
rows = query.get_compiler(self.db).execute_sql(ROW_COUNT)
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, returning_fields=None):
"""
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
if returning_fields is None:
return query.get_compiler(self.db).execute_sql(ROW_COUNT)
return query.get_compiler(self.db).execute_returning_sql(returning_fields)
_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 not obj._is_pk_set():
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,
fetch_mode=self._fetch_mode,
)
qs._prefetch_related_lookups = self._prefetch_related_lookups[:]
return qs
def _values(self, *fields, **expressions):
clone = self._chain()
if expressions:
# RemovedInDjango70Warning: When the deprecation ends, deindent as:
# clone = clone.annotate(**expressions)
with warnings.catch_warnings(
action="ignore", category=RemovedInDjango70Warning ):
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:
if len(fields) > 1:
raise TypeError( "'flat' is not valid when values_list is called with more than one " "field." )
elif not fields:
# RemovedInDjango70Warning: When the deprecation ends, replace
# with:
# raise TypeError(
# "'flat' is not valid when values_list is called with no "
# "fields."
# )
warnings.warn( "Calling values_list() with no field name and flat=True "
"is deprecated. Pass an explicit field name instead, like "
"'pk'.",
RemovedInDjango70Warning,
)
fields = [self.model._meta.concrete_fields[0].attname]
field_names = {f: False for f in fields if not hasattr(f, "resolve_expression")}
_fields = []
expressions = {}
counter = 1
for field in fields:
field_name = field
expression = None
if hasattr(field, "resolve_expression"):
field_name = getattr( field, "default_alias", field.__class__.__name__.lower()
)
expression = field
# For backward compatibility reasons expressions are always
# prefixed with the counter even if their default alias doesn't
# collide with field names. Changing this logic could break
# some usage of named=True.
seen = True
elif seen := field_names[field_name]:
expression = F(field_name)
if seen:
field_name_prefix = field_name
while (field_name := f"{field_name_prefix}{counter}") in field_names:
counter += 1
if expression is not None:
expressions[field_name] = expression
field_names[field_name] = True
_fields.append(field_name)
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") )
def datetimes(self, field_name, kind, order="ASC", tzinfo=None):
"""
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,
), 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 invalid_kwargs := PROHIBITED_FILTER_KWARGS.intersection(kwargs):
invalid_kwargs_str = ", ".join(f"'{k}'" for k in sorted(invalid_kwargs))
raise TypeError(f"The following kwargs are invalid: {invalid_kwargs_str}")
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.default_ordering = True
self._clear_ordering_in_combined_queries(clone.query, other_qs)
clone.query.clear_limits()
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)
elif not other_qs:
return self
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:
# RemovedInDjango70Warning: when the deprecation ends, raise a
# TypeError instead.
warn_about_external_use(
"Calling select_related() with no arguments is deprecated. " "Specify the fields to fetch instead.",
category=RemovedInDjango70Warning,
skip_name_prefixes=("django.db.models",), )
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 raises TypeError if default_alias
# can't be set automatically or AttributeError if it isn't an
# attribute.
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, AttributeError):
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 remove 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
def fetch_mode(self, fetch_mode):
"""Set the fetch mode for the QuerySet."""
clone = self._chain()
clone._fetch_mode = fetch_mode
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 totally_ordered(self):
"""
Returns True if the QuerySet is ordered and the ordering is
deterministic. This requires that the ordering includes a field
(or set of fields) that is unique and non-nullable.
For queries involving a GROUP BY clause, the model's default
ordering is ignored. Ordering specified via .extra(order_by=...)
is also ignored.
"""
if not self.ordered:
return False
ordering = self.query.order_by
if not ordering and self.query.default_ordering:
ordering = self.query.get_meta().ordering
if not ordering:
return False
opts = self.model._meta
pk_fields = {f.attname for f in opts.pk_fields}
candidate_fields = set()
for part in ordering:
# Search for single field providing a total ordering.
field_name = None
if isinstance(part, str):
field_name = part.lstrip("-")
elif isinstance(part, F):
field_name = part.name
elif isinstance(part, OrderBy) and isinstance(part.expression, F):
field_name = part.expression.name
if annotation_col := self.query.annotations.get(field_name):
if isinstance(annotation_col, Col):
if annotation_col.alias == self.query.base_table:
candidate_fields.add(annotation_col.target)
elif isinstance(annotation_col, ColPairs):
candidate_fields |= { c.target
for c in annotation_col.get_cols() if c.alias == self.query.base_table
}
elif field_name:
if field_name == "pk":
return True
# Normalize attname references by using get_field().
try:
field = opts.get_field(field_name)
except exceptions.FieldDoesNotExist:
# Could be "?" for random ordering or a related field
# lookup. Skip this part of introspection for now.
continue
else:
# Ordering by a related field name orders by the referenced
# model's ordering. Skip this introspection for now.
if field.remote_field and field_name == field.name:
continue
candidate_fields.add(field)
candidate_attnames = set()
for field in candidate_fields:
if field.unique and not field.null:
return True
candidate_attnames.add(field.attname)
# Account for members of a CompositePrimaryKey.
if candidate_attnames.issuperset(pk_fields):
return True
# No single total ordering field, try unique_together and total
# unique constraints.
constraint_field_names = (
*opts.unique_together,
*(constraint.fields for constraint in opts.total_unique_constraints), )
for field_names in constraint_field_names:
# Normalize attname references by using get_field().
try:
fields = [opts.get_field(field_name) for field_name in field_names]
except exceptions.FieldDoesNotExist:
continue
# Composite unique constraints containing a nullable column
# cannot ensure total ordering.
if any(field.null for field in fields):
continue
if candidate_attnames.issuperset(field.attname for field in fields):
return True
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 = []
returning_fields = ( self.model._meta.db_returning_fields
if ( connection.features.can_return_rows_from_bulk_insert and (on_conflict is None or on_conflict == OnConflict.UPDATE)
)
else None )
batches = [objs[i : i + batch_size] for i in range(0, len(objs), batch_size)]
if len(batches) > 1:
context = transaction.atomic(using=self.db, savepoint=False)
else:
context = nullcontext()
with context:
for item in batches:
inserted_rows.extend( self._insert(
item, fields=fields, using=self.db,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
returning_fields=returning_fields,
) )
return inserted_rows
def _disable_cloning(self):
"""
Prevent calls to _chain() from creating a new QuerySet via _clone().
All subsequent QuerySet mutations will occur on this instance until
_enable_cloning() is used.
"""
self._cloning_enabled = False
return self
def _enable_cloning(self):
"""
Allow calls to _chain() to create a new QuerySet via _clone(). Restores
the default behavior where any QuerySet mutation will return a new
QuerySet instance. Necessary only when there has been a
_disable_cloning() call previously.
"""
self._cloning_enabled = True
return self
def _avoid_cloning(self):
"""
Temporarily prevent QuerySet _clone() operations, restoring the default
behavior on exit. For the duration of the context managed statement,
all operations (e.g. filter(), exclude(), etc.) will mutate the same
QuerySet instance.
@contextlib.contextmanager is intentionally not used for performance
reasons.
"""
return PreventQuerySetCloning(self)
def _chain(self):
"""
Return a copy of the current QuerySet that's ready for another
operation.
If the QuerySet has opted in to in-place mutations via
_disable_cloning() temporarily, the copy doesn't occur and instead the
same QuerySet instance will be modified.
"""
if not self._cloning_enabled:
obj = self
else:
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._fetch_mode = self._fetch_mode
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):
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)
# Raise if the pk fields are not in the group_by.
and self.model._meta.pk
not in {col.output_field for col in self.query.group_by}
and set(self.model._meta.pk_fields).difference(
{col.target 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()." )
def _clear_ordering_in_combined_queries(self, cloned_query, other_qs):
combined_queries = [self.query]
for qs in other_qs:
query = qs.query.clone()
query.clear_ordering(force=False, clear_default=False)
combined_queries.append(query)
cloned_query.combined_queries = tuple(combined_queries)