Commit 4c4d0850 authored by Luke Plant's avatar Luke Plant
Browse files

Fixed #17991 - prefetch_related fails with GenericRelation and varchar ID field 

Thanks to okke@formsma.nl for the report, and carmandrew@gmail.com for the tests.
parent 4ea81051

django/contrib/contenttypes/generic.py

+4 −2
Original line number Diff line number Diff line
@@ -5,7 +5,6 @@ from __future__ import unicode_literals 


from collections import defaultdict

from functools import partial

from operator import attrgetter



from django.core.exceptions import ObjectDoesNotExist

from django.db import connection
@@ -329,8 +328,11 @@ def create_generic_related_manager(superclass): 
                    set(obj._get_pk_val() for obj in instances)

                }

            qs = super(GenericRelatedObjectManager, self).get_query_set().using(db).filter(**query)

            # We (possibly) need to convert object IDs to the type of the

            # instances' PK in order to match up instances:

            object_id_converter = instances[0]._meta.pk.to_python

            return (qs,

                    attrgetter(self.object_id_field_name),

                    lambda relobj: object_id_converter(getattr(relobj, self.object_id_field_name)),

                    lambda obj: obj._get_pk_val(),

                    False,

                    self.prefetch_cache_name)

tests/modeltests/prefetch_related/models.py

+9 −1
Original line number Diff line number Diff line
@@ -125,6 +125,10 @@ class TaggedItem(models.Model): 
                                      related_name='taggeditem_set3')

    created_by_fkey = models.PositiveIntegerField(null=True)

    created_by = generic.GenericForeignKey('created_by_ct', 'created_by_fkey',)

    favorite_ct = models.ForeignKey(ContentType, null=True,

                                    related_name='taggeditem_set4')

    favorite_fkey = models.CharField(max_length=64, null=True)

    favorite = generic.GenericForeignKey('favorite_ct', 'favorite_fkey')



    def __str__(self):

        return self.tag
@@ -132,7 +136,11 @@ class TaggedItem(models.Model): 


class Bookmark(models.Model):

    url = models.URLField()

    tags = generic.GenericRelation(TaggedItem)

    tags = generic.GenericRelation(TaggedItem, related_name='bookmarks')

    favorite_tags = generic.GenericRelation(TaggedItem,

                                    content_type_field='favorite_ct',

                                    object_id_field='favorite_fkey',

                                    related_name='favorite_bookmarks')





class Comment(models.Model):

tests/modeltests/prefetch_related/tests.py

+10 −0
Original line number Diff line number Diff line
@@ -319,6 +319,16 @@ class GenericRelationTests(TestCase): 
                    for t in b.tags.all()]

            self.assertEqual(sorted(tags), ["django", "python"])



    def test_charfield_GFK(self):

        b = Bookmark.objects.create(url='http://www.djangoproject.com/')

        t1 = TaggedItem.objects.create(content_object=b, tag='django')

        t2 = TaggedItem.objects.create(content_object=b, favorite=b, tag='python')



        with self.assertNumQueries(3):

            bookmark = Bookmark.objects.filter(pk=b.pk).prefetch_related('tags', 'favorite_tags')[0]

            self.assertEqual(sorted([i.tag for i in bookmark.tags.all()]), ["django", "python"])

            self.assertEqual([i.tag for i in bookmark.favorite_tags.all()], ["python"])





class MultiTableInheritanceTest(TestCase):