mirrors/django
1
0
Fork 0
mirror of https://github.com/django/django.git synced 2025-08-03 10:34:04 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Fixed #29725 -- Removed unnecessary join in QuerySet.count() and exists() on a many-to-many relation.

Browse source
This commit is contained in:
oliver 2018-10-16 00:01:57 +09:00 • committed by Tim Graham
parent f2e2a1bd4b
commit 1299421cad
3 changed files with 80 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

46
tests/many_to_many/tests.py
View file

@ -1,7 +1,13 @@
from django.db import transaction
from django.test import TestCase
from unittest import mock
from .models import Article, InheritedArticleA, InheritedArticleB, Publication
from django.db import connection, transaction
from django.test import TestCase, skipUnlessDBFeature
from django.test.utils import CaptureQueriesContext
from .models import (
Article, InheritedArticleA, InheritedArticleB, NullablePublicationThrough,
NullableTargetArticle, Publication,
)
class ManyToManyTests(TestCase):
@ -554,3 +560,37 @@ class ManyToManyTests(TestCase):
]
)
self.assertQuerysetEqual(b.publications.all(), ['<Publication: Science Weekly>'])
class ManyToManyQueryTests(TestCase):
@classmethod
def setUpTestData(cls):
cls.article = Article.objects.create(headline='Django lets you build Web apps easily')
cls.nullable_target_article = NullableTargetArticle.objects.create(headline='The python is good')
NullablePublicationThrough.objects.create(article=cls.nullable_target_article, publication=None)
@skipUnlessDBFeature('supports_foreign_keys')
def test_count_join_optimization(self):
with CaptureQueriesContext(connection) as query:
self.article.publications.count()
self.assertNotIn('JOIN', query[0]['sql'])
self.assertEqual(self.nullable_target_article.publications.count(), 0)
def test_count_join_optimization_disabled(self):
with mock.patch.object(connection.features, 'supports_foreign_keys', False), \
CaptureQueriesContext(connection) as query:
self.article.publications.count()
self.assertIn('JOIN', query[0]['sql'])
@skipUnlessDBFeature('supports_foreign_keys')
def test_exists_join_optimization(self):
with CaptureQueriesContext(connection) as query:
self.article.publications.exists()
self.assertNotIn('JOIN', query[0]['sql'])
self.assertIs(self.nullable_target_article.publications.exists(), False)
def test_exists_join_optimization_disabled(self):
with mock.patch.object(connection.features, 'supports_foreign_keys', False), \
CaptureQueriesContext(connection) as query:
self.article.publications.exists()
self.assertIn('JOIN', query[0]['sql'])