Ticket #3215: 3215.patch

django/db/models/query.py

@@ -1 +1 @@
 from django.db import backend, connection, transaction
 from django.db.models.fields import DateField, FieldDoesNotExist
+from django.db.models.fields.generic import GenericRelation
 from django.db.models import signals
 from django.dispatch import dispatcher
 from django.utils.datastructures import SortedDict
@@ -986 +987 @@
                         ','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
                     pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
         for f in cls._meta.many_to_many:
+            if isinstance(f, GenericRelation):
+                from django.contrib.contenttypes.models import ContentType 
+                query_extra = 'AND %s=%%s' % f.rel.to._meta.get_field(f.content_type_field_name).column
+                args_extra = [ContentType.objects.get_for_model(cls).id]
+            else:
+                query_extra = ''
+                args_extra = []
             for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
-                cursor.execute("DELETE FROM %s WHERE %s IN (%s)" % \
+                cursor.execute(("DELETE FROM %s WHERE %s IN (%s)" % \
                     (qn(f.m2m_db_table()), qn(f.m2m_column_name()),
-                    ','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
-                    pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
+                    ','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]]))) + query_extra,
+                    pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE] + args_extra)
         for field in cls._meta.fields:
             if field.rel and field.null and field.rel.to in seen_objs:
                 for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):

tests/modeltests/generic_relations/models.py

@@ -105 +105 @@
 [<TaggedItem: shiny>]
 >>> TaggedItem.objects.filter(content_type__pk=ctype.id, object_id=quartz.id)
 [<TaggedItem: clearish>]
+
+# If you delete an object with an explicit Generic relation, the related
+# objects are deleted when the source object is deleted.
+>>> [(t.tag, t.content_type, t.object_id) for t in TaggedItem.objects.all()]
+[('clearish', <ContentType: mineral>, 1), ('fatty', <ContentType: vegetable>, 2), ('hairy', <ContentType: animal>, 1), ('salty', <ContentType: vegetable>, 2), ('shiny', <ContentType: animal>, 2), ('yellow', <ContentType: animal>, 1)]
+
+>>> lion.delete()
+>>> [(t.tag, t.content_type, t.object_id) for t in TaggedItem.objects.all()]
+[('clearish', <ContentType: mineral>, 1), ('fatty', <ContentType: vegetable>, 2), ('salty', <ContentType: vegetable>, 2), ('shiny', <ContentType: animal>, 2)]
+
+# If Generic Relation is not explicitly defined, any related objects 
+# remain after deletion of the source object.
+>>> quartz.delete()
+>>> [(t.tag, t.content_type, t.object_id) for t in TaggedItem.objects.all()]
+[('clearish', <ContentType: mineral>, 1), ('fatty', <ContentType: vegetable>, 2), ('salty', <ContentType: vegetable>, 2), ('shiny', <ContentType: animal>, 2)]
+
 """}