diff --git a/django/db/models/base.py b/django/db/models/base.py index 243093da44..3d40bc4286 100644 --- a/django/db/models/base.py +++ b/django/db/models/base.py @@ -740,12 +740,16 @@ class Model(AltersData, metaclass=ModelBase): # Clear cached relations. for field in self._meta.related_objects: - if field.is_cached(self): + if (fields is None or field.name in fields) and field.is_cached(self): field.delete_cached_value(self) # Clear cached private relations. for field in self._meta.private_fields: - if field.is_relation and field.is_cached(self): + if ( + (fields is None or field.name in fields) + and field.is_relation + and field.is_cached(self) + ): field.delete_cached_value(self) self._state.db = db_instance._state.db diff --git a/tests/contenttypes_tests/test_fields.py b/tests/contenttypes_tests/test_fields.py index 5510f34cd0..15f1dafd63 100644 --- a/tests/contenttypes_tests/test_fields.py +++ b/tests/contenttypes_tests/test_fields.py @@ -45,6 +45,18 @@ class GenericForeignKeyTests(TestCase): new_entity = answer.question self.assertIsNot(old_entity, new_entity) + def test_clear_cached_generic_relation_explicit_fields(self): + question = Question.objects.create(text="question") + answer = Answer.objects.create(text="answer", question=question) + old_question_obj = answer.question + # The reverse relation is not refreshed if not passed explicitly in + # `fields`. + answer.refresh_from_db(fields=["text"]) + self.assertIs(answer.question, old_question_obj) + answer.refresh_from_db(fields=["question"]) + self.assertIsNot(answer.question, old_question_obj) + self.assertEqual(answer.question, old_question_obj) + class GenericRelationTests(TestCase): def test_value_to_string(self): @@ -55,6 +67,29 @@ class GenericRelationTests(TestCase): self.assertCountEqual(result, [answer1.pk, answer2.pk]) +class DeferredGenericRelationTests(TestCase): + @classmethod + def setUpTestData(cls): + cls.question = Question.objects.create(text="question") + cls.answer = Answer.objects.create(text="answer", question=cls.question) + + def test_defer_not_clear_cached_private_relations(self): + obj = Answer.objects.defer("text").get(pk=self.answer.pk) + with self.assertNumQueries(1): + obj.question + obj.text # Accessing a deferred field. + with self.assertNumQueries(0): + obj.question + + def test_only_not_clear_cached_private_relations(self): + obj = Answer.objects.only("content_type", "object_id").get(pk=self.answer.pk) + with self.assertNumQueries(1): + obj.question + obj.text # Accessing a deferred field. + with self.assertNumQueries(0): + obj.question + + class GetPrefetchQuerySetDeprecation(TestCase): def test_generic_relation_warning(self): Question.objects.create(text="test") diff --git a/tests/defer/models.py b/tests/defer/models.py index 6de2e2af97..560e54c8c0 100644 --- a/tests/defer/models.py +++ b/tests/defer/models.py @@ -19,6 +19,14 @@ class Primary(models.Model): return self.name +class PrimaryOneToOne(models.Model): + name = models.CharField(max_length=50) + value = models.CharField(max_length=50) + related = models.OneToOneField( + Secondary, models.CASCADE, related_name="primary_o2o" + ) + + class Child(Primary): pass diff --git a/tests/defer/tests.py b/tests/defer/tests.py index c7eb03dc8a..3945b667ba 100644 --- a/tests/defer/tests.py +++ b/tests/defer/tests.py @@ -6,6 +6,7 @@ from .models import ( Child, ChildProxy, Primary, + PrimaryOneToOne, RefreshPrimaryProxy, Secondary, ShadowChild, @@ -326,3 +327,28 @@ class InvalidDeferTests(SimpleTestCase): ) with self.assertRaisesMessage(FieldError, msg): Primary.objects.only("name").select_related("related")[0] + + +class DeferredRelationTests(TestCase): + @classmethod + def setUpTestData(cls): + cls.secondary = Secondary.objects.create(first="a", second="b") + cls.primary = PrimaryOneToOne.objects.create( + name="Bella", value="Baxter", related=cls.secondary + ) + + def test_defer_not_clear_cached_relations(self): + obj = Secondary.objects.defer("first").get(pk=self.secondary.pk) + with self.assertNumQueries(1): + obj.primary_o2o + obj.first # Accessing a deferred field. + with self.assertNumQueries(0): + obj.primary_o2o + + def test_only_not_clear_cached_relations(self): + obj = Secondary.objects.only("first").get(pk=self.secondary.pk) + with self.assertNumQueries(1): + obj.primary_o2o + obj.second # Accessing a deferred field. + with self.assertNumQueries(0): + obj.primary_o2o