from __future__ import unicode_literals from django.test import TestCase from .models import ( Event, Movie, Package, PackageNullFK, Person, Screening, ScreeningNullFK, ) # These are tests for #16715. The basic scheme is always the same: 3 models with # 2 relations. The first relation may be null, while the second is non-nullable. # In some cases, Django would pick the wrong join type for the second relation, # resulting in missing objects in the queryset. # # Model A # | (Relation A/B : nullable) # Model B # | (Relation B/C : non-nullable) # Model C # # Because of the possibility of NULL rows resulting from the LEFT OUTER JOIN # between Model A and Model B (i.e. instances of A without reference to B), # the second join must also be LEFT OUTER JOIN, so that we do not ignore # instances of A that do not reference B. # # Relation A/B can either be an explicit foreign key or an implicit reverse # relation such as introduced by one-to-one relations (through multi-table # inheritance). class NestedForeignKeysTests(TestCase): def setUp(self): self.director = Person.objects.create(name='Terry Gilliam / Terry Jones') self.movie = Movie.objects.create(title='Monty Python and the Holy Grail', director=self.director) # This test failed in #16715 because in some cases INNER JOIN was selected # for the second foreign key relation instead of LEFT OUTER JOIN. def test_inheritance(self): Event.objects.create() Screening.objects.create(movie=self.movie) self.assertEqual(len(Event.objects.all()), 2) self.assertEqual(len(Event.objects.select_related('screening')), 2) # This failed. self.assertEqual(len(Event.objects.select_related('screening__movie')), 2) self.assertEqual(len(Event.objects.values()), 2) self.assertEqual(len(Event.objects.values('screening__pk')), 2) self.assertEqual(len(Event.objects.values('screening__movie__pk')), 2) self.assertEqual(len(Event.objects.values('screening__movie__title')), 2) # This failed. self.assertEqual(len(Event.objects.values('screening__movie__pk', 'screening__movie__title')), 2) # Simple filter/exclude queries for good measure. self.assertEqual(Event.objects.filter(screening__movie=self.movie).count(), 1) self.assertEqual(Event.objects.exclude(screening__movie=self.movie).count(), 1) # These all work because the second foreign key in the chain has null=True. def test_inheritance_null_FK(self): Event.objects.create() ScreeningNullFK.objects.create(movie=None) ScreeningNullFK.objects.create(movie=self.movie) self.assertEqual(len(Event.objects.all()), 3) self.assertEqual(len(Event.objects.select_related('screeningnullfk')), 3) self.assertEqual(len(Event.objects.select_related('screeningnullfk__movie')), 3) self.assertEqual(len(Event.objects.values()), 3) self.assertEqual(len(Event.objects.values('screeningnullfk__pk')), 3) self.assertEqual(len(Event.objects.values('screeningnullfk__movie__pk')), 3) self.assertEqual(len(Event.objects.values('screeningnullfk__movie__title')), 3) self.assertEqual(len(Event.objects.values('screeningnullfk__movie__pk', 'screeningnullfk__movie__title')), 3) self.assertEqual(Event.objects.filter(screeningnullfk__movie=self.movie).count(), 1) self.assertEqual(Event.objects.exclude(screeningnullfk__movie=self.movie).count(), 2) def test_null_exclude(self): screening = ScreeningNullFK.objects.create(movie=None) ScreeningNullFK.objects.create(movie=self.movie) self.assertEqual( list(ScreeningNullFK.objects.exclude(movie__id=self.movie.pk)), [screening]) # This test failed in #16715 because in some cases INNER JOIN was selected # for the second foreign key relation instead of LEFT OUTER JOIN. def test_explicit_ForeignKey(self): Package.objects.create() screening = Screening.objects.create(movie=self.movie) Package.objects.create(screening=screening) self.assertEqual(len(Package.objects.all()), 2) self.assertEqual(len(Package.objects.select_related('screening')), 2) self.assertEqual(len(Package.objects.select_related('screening__movie')), 2) self.assertEqual(len(Package.objects.values()), 2) self.assertEqual(len(Package.objects.values('screening__pk')), 2) self.assertEqual(len(Package.objects.values('screening__movie__pk')), 2) self.assertEqual(len(Package.objects.values('screening__movie__title')), 2) # This failed. self.assertEqual(len(Package.objects.values('screening__movie__pk', 'screening__movie__title')), 2) self.assertEqual(Package.objects.filter(screening__movie=self.movie).count(), 1) self.assertEqual(Package.objects.exclude(screening__movie=self.movie).count(), 1) # These all work because the second foreign key in the chain has null=True. def test_explicit_ForeignKey_NullFK(self): PackageNullFK.objects.create() screening = ScreeningNullFK.objects.create(movie=None) screening_with_movie = ScreeningNullFK.objects.create(movie=self.movie) PackageNullFK.objects.create(screening=screening) PackageNullFK.objects.create(screening=screening_with_movie) self.assertEqual(len(PackageNullFK.objects.all()), 3) self.assertEqual(len(PackageNullFK.objects.select_related('screening')), 3) self.assertEqual(len(PackageNullFK.objects.select_related('screening__movie')), 3) self.assertEqual(len(PackageNullFK.objects.values()), 3) self.assertEqual(len(PackageNullFK.objects.values('screening__pk')), 3) self.assertEqual(len(PackageNullFK.objects.values('screening__movie__pk')), 3) self.assertEqual(len(PackageNullFK.objects.values('screening__movie__title')), 3) self.assertEqual(len(PackageNullFK.objects.values('screening__movie__pk', 'screening__movie__title')), 3) self.assertEqual(PackageNullFK.objects.filter(screening__movie=self.movie).count(), 1) self.assertEqual(PackageNullFK.objects.exclude(screening__movie=self.movie).count(), 2) # Some additional tests for #16715. The only difference is the depth of the # nesting as we now use 4 models instead of 3 (and thus 3 relations). This # checks if promotion of join types works for deeper nesting too. class DeeplyNestedForeignKeysTests(TestCase): def setUp(self): self.director = Person.objects.create(name='Terry Gilliam / Terry Jones') self.movie = Movie.objects.create(title='Monty Python and the Holy Grail', director=self.director) def test_inheritance(self): Event.objects.create() Screening.objects.create(movie=self.movie) self.assertEqual(len(Event.objects.all()), 2) self.assertEqual(len(Event.objects.select_related('screening__movie__director')), 2) self.assertEqual(len(Event.objects.values()), 2) self.assertEqual(len(Event.objects.values('screening__movie__director__pk')), 2) self.assertEqual(len(Event.objects.values('screening__movie__director__name')), 2) self.assertEqual(len(Event.objects.values('screening__movie__director__pk', 'screening__movie__director__name')), 2) self.assertEqual(len(Event.objects.values('screening__movie__pk', 'screening__movie__director__pk')), 2) self.assertEqual(len(Event.objects.values('screening__movie__pk', 'screening__movie__director__name')), 2) self.assertEqual(len(Event.objects.values('screening__movie__title', 'screening__movie__director__pk')), 2) self.assertEqual(len(Event.objects.values('screening__movie__title', 'screening__movie__director__name')), 2) self.assertEqual(Event.objects.filter(screening__movie__director=self.director).count(), 1) self.assertEqual(Event.objects.exclude(screening__movie__director=self.director).count(), 1) def test_explicit_ForeignKey(self): Package.objects.create() screening = Screening.objects.create(movie=self.movie) Package.objects.create(screening=screening) self.assertEqual(len(Package.objects.all()), 2) self.assertEqual(len(Package.objects.select_related('screening__movie__director')), 2) self.assertEqual(len(Package.objects.values()), 2) self.assertEqual(len(Package.objects.values('screening__movie__director__pk')), 2) self.assertEqual(len(Package.objects.values('screening__movie__director__name')), 2) self.assertEqual(len(Package.objects.values('screening__movie__director__pk', 'screening__movie__director__name')), 2) self.assertEqual(len(Package.objects.values('screening__movie__pk', 'screening__movie__director__pk')), 2) self.assertEqual(len(Package.objects.values('screening__movie__pk', 'screening__movie__director__name')), 2) self.assertEqual(len(Package.objects.values('screening__movie__title', 'screening__movie__director__pk')), 2) self.assertEqual(len(Package.objects.values('screening__movie__title', 'screening__movie__director__name')), 2) self.assertEqual(Package.objects.filter(screening__movie__director=self.director).count(), 1) self.assertEqual(Package.objects.exclude(screening__movie__director=self.director).count(), 1)