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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)
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