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Code Issues 32 Releases Wiki Activity

Fixed #15579 -- Added ability to delete only child models in multi-table inheritance.

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This commit is contained in:
Andriy Sokolovskiy
2015-02-07 01:16:26 +02:00
committed by Tim Graham
parent b9cb81570e
commit 81c2d9f60b
5 changed files with 41 additions and 18 deletions
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4
django/db/models/base.py
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@@ -827,7 +827,7 @@ class Model(six.with_metaclass(ModelBase)):
return manager._insert([self], fields=fields, return_id=update_pk,
using=using, raw=raw)
def delete(self, using=None):
def delete(self, using=None, keep_parents=False):
using = using or router.db_for_write(self.__class__, instance=self)
assert self._get_pk_val() is not None, (
"%s object can't be deleted because its %s attribute is set to None." %
@@ -835,7 +835,7 @@ class Model(six.with_metaclass(ModelBase)):
)
collector = Collector(using=using)
collector.collect([self])
collector.collect([self], keep_parents=keep_parents)
collector.delete()
delete.alters_data = True

34
django/db/models/deletion.py
View File

@@ -174,7 +174,7 @@ class Collector(object):
return [objs]
def collect(self, objs, source=None, nullable=False, collect_related=True,
source_attr=None, reverse_dependency=False):
source_attr=None, reverse_dependency=False, keep_parents=False):
"""
Adds 'objs' to the collection of objects to be deleted as well as all
parent instances. 'objs' must be a homogeneous iterable collection of
@@ -189,6 +189,9 @@ class Collector(object):
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 False, data of parent's models will be not
deleted.
"""
if self.can_fast_delete(objs):
self.fast_deletes.append(objs)
@@ -200,20 +203,21 @@ class Collector(object):
model = new_objs[0].__class__
# 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 six.itervalues(concrete_model._meta.parents):
if ptr:
# FIXME: This seems to be buggy and execute a query for each
# parent object fetch. We have the parent data in the obj,
# but we don't have a nice way to turn that data into parent
# object instance.
parent_objs = [getattr(obj, ptr.name) for obj in new_objs]
self.collect(parent_objs, source=model,
source_attr=ptr.rel.related_name,
collect_related=False,
reverse_dependency=True)
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 six.itervalues(concrete_model._meta.parents):
if ptr:
# FIXME: This seems to be buggy and execute a query for each
# parent object fetch. We have the parent data in the obj,
# but we don't have a nice way to turn that data into parent
# object instance.
parent_objs = [getattr(obj, ptr.name) for obj in new_objs]
self.collect(parent_objs, source=model,
source_attr=ptr.rel.related_name,
collect_related=False,
reverse_dependency=True)
if collect_related:
for related in get_candidate_relations_to_delete(model._meta):