from django.db import IntegrityError, connection, transaction from django.test import TestCase from django.utils.deprecation import RemovedInDjango60Warning from .models import ( Bar, Director, Favorites, HiddenPointer, ManualPrimaryKey, MultiModel, Place, Pointer, RelatedModel, Restaurant, School, Target, ToFieldPointer, UndergroundBar, Waiter, ) class OneToOneTests(TestCase): @classmethod def setUpTestData(cls): cls.p1 = Place.objects.create(name="Demon Dogs", address="944 W. Fullerton") cls.p2 = Place.objects.create(name="Ace Hardware", address="1013 N. Ashland") cls.r1 = Restaurant.objects.create( place=cls.p1, serves_hot_dogs=True, serves_pizza=False ) cls.b1 = Bar.objects.create(place=cls.p1, serves_cocktails=False) def test_getter(self): # A Restaurant can access its place. self.assertEqual(repr(self.r1.place), "") # A Place can access its restaurant, if available. self.assertEqual( repr(self.p1.restaurant), "" ) # p2 doesn't have an associated restaurant. with self.assertRaisesMessage( Restaurant.DoesNotExist, "Place has no restaurant" ): self.p2.restaurant # The exception raised on attribute access when a related object # doesn't exist should be an instance of a subclass of `AttributeError` # refs #21563 self.assertFalse(hasattr(self.p2, "restaurant")) def test_setter(self): # Set the place using assignment notation. Because place is the primary # key on Restaurant, the save will create a new restaurant self.r1.place = self.p2 self.r1.save() self.assertEqual( repr(self.p2.restaurant), "" ) self.assertEqual(repr(self.r1.place), "") self.assertEqual(self.p2.pk, self.r1.pk) # Set the place back again, using assignment in the reverse direction. self.p1.restaurant = self.r1 self.assertEqual( repr(self.p1.restaurant), "" ) r = Restaurant.objects.get(pk=self.p1.id) self.assertEqual(repr(r.place), "") def test_manager_all(self): # Restaurant.objects.all() just returns the Restaurants, not the Places. self.assertSequenceEqual(Restaurant.objects.all(), [self.r1]) # Place.objects.all() returns all Places, regardless of whether they # have Restaurants. self.assertSequenceEqual(Place.objects.order_by("name"), [self.p2, self.p1]) def test_manager_get(self): def assert_get_restaurant(**params): self.assertEqual( repr(Restaurant.objects.get(**params)), "", ) assert_get_restaurant(place__id__exact=self.p1.pk) assert_get_restaurant(place__id=self.p1.pk) assert_get_restaurant(place__exact=self.p1.pk) assert_get_restaurant(place__exact=self.p1) assert_get_restaurant(place=self.p1.pk) assert_get_restaurant(place=self.p1) assert_get_restaurant(pk=self.p1.pk) assert_get_restaurant(place__pk__exact=self.p1.pk) assert_get_restaurant(place__pk=self.p1.pk) assert_get_restaurant(place__name__startswith="Demon") def assert_get_place(**params): self.assertEqual( repr(Place.objects.get(**params)), "" ) assert_get_place(restaurant__place__exact=self.p1.pk) assert_get_place(restaurant__place__exact=self.p1) assert_get_place(restaurant__place__pk=self.p1.pk) assert_get_place(restaurant__exact=self.p1.pk) assert_get_place(restaurant__exact=self.r1) assert_get_place(restaurant__pk=self.p1.pk) assert_get_place(restaurant=self.p1.pk) assert_get_place(restaurant=self.r1) assert_get_place(id__exact=self.p1.pk) assert_get_place(pk=self.p1.pk) def test_foreign_key(self): # Add a Waiter to the Restaurant. w = self.r1.waiter_set.create(name="Joe") self.assertEqual( repr(w), "" ) # Query the waiters def assert_filter_waiters(**params): self.assertSequenceEqual(Waiter.objects.filter(**params), [w]) assert_filter_waiters(restaurant__place__exact=self.p1.pk) assert_filter_waiters(restaurant__place__exact=self.p1) assert_filter_waiters(restaurant__place__pk=self.p1.pk) assert_filter_waiters(restaurant__exact=self.r1.pk) assert_filter_waiters(restaurant__exact=self.r1) assert_filter_waiters(restaurant__pk=self.r1.pk) assert_filter_waiters(restaurant=self.r1.pk) assert_filter_waiters(restaurant=self.r1) assert_filter_waiters(id__exact=w.pk) assert_filter_waiters(pk=w.pk) # Delete the restaurant; the waiter should also be removed r = Restaurant.objects.get(pk=self.r1.pk) r.delete() self.assertEqual(Waiter.objects.count(), 0) def test_multiple_o2o(self): # One-to-one fields still work if you create your own primary key o1 = ManualPrimaryKey(primary_key="abc123", name="primary") o1.save() o2 = RelatedModel(link=o1, name="secondary") o2.save() # You can have multiple one-to-one fields on a model, too. x1 = MultiModel(link1=self.p1, link2=o1, name="x1") x1.save() self.assertEqual(repr(o1.multimodel), "") # This will fail because each one-to-one field must be unique (and # link2=o1 was used for x1, above). mm = MultiModel(link1=self.p2, link2=o1, name="x1") with self.assertRaises(IntegrityError): with transaction.atomic(): mm.save() def test_unsaved_object(self): """ #10811 -- Assigning an unsaved object to a OneToOneField should raise an exception. """ place = Place(name="User", address="London") with self.assertRaises(Restaurant.DoesNotExist): place.restaurant msg = ( "save() prohibited to prevent data loss due to unsaved related object " "'place'." ) with self.assertRaisesMessage(ValueError, msg): Restaurant.objects.create( place=place, serves_hot_dogs=True, serves_pizza=False ) # place should not cache restaurant with self.assertRaises(Restaurant.DoesNotExist): place.restaurant def test_reverse_relationship_cache_cascade(self): """ Regression test for #9023: accessing the reverse relationship shouldn't result in a cascading delete(). """ bar = UndergroundBar.objects.create(place=self.p1, serves_cocktails=False) # The bug in #9023: if you access the one-to-one relation *before* # setting to None and deleting, the cascade happens anyway. self.p1.undergroundbar bar.place.name = "foo" bar.place = None bar.save() self.p1.delete() self.assertEqual(Place.objects.count(), 1) self.assertEqual(UndergroundBar.objects.count(), 1) def test_create_models_m2m(self): """ Models are created via the m2m relation if the remote model has a OneToOneField (#1064, #1506). """ f = Favorites(name="Fred") f.save() f.restaurants.set([self.r1]) self.assertSequenceEqual(f.restaurants.all(), [self.r1]) def test_reverse_object_cache(self): """ The name of the cache for the reverse object is correct (#7173). """ self.assertEqual(self.p1.restaurant, self.r1) self.assertEqual(self.p1.bar, self.b1) def test_assign_none_reverse_relation(self): p = Place.objects.get(name="Demon Dogs") # Assigning None succeeds if field is null=True. ug_bar = UndergroundBar.objects.create(place=p, serves_cocktails=False) p.undergroundbar = None self.assertIsNone(ug_bar.place) ug_bar.save() ug_bar.refresh_from_db() self.assertIsNone(ug_bar.place) def test_assign_none_null_reverse_relation(self): p = Place.objects.get(name="Demon Dogs") # Assigning None doesn't throw AttributeError if there isn't a related # UndergroundBar. p.undergroundbar = None def test_assign_none_to_null_cached_reverse_relation(self): p = Place.objects.get(name="Demon Dogs") # Prime the relation's cache with a value of None. with self.assertRaises(Place.undergroundbar.RelatedObjectDoesNotExist): getattr(p, "undergroundbar") # Assigning None works if there isn't a related UndergroundBar and the # reverse cache has a value of None. p.undergroundbar = None def test_assign_o2o_id_value(self): b = UndergroundBar.objects.create(place=self.p1) b.place_id = self.p2.pk b.save() self.assertEqual(b.place_id, self.p2.pk) self.assertFalse(UndergroundBar.place.is_cached(b)) self.assertEqual(b.place, self.p2) self.assertTrue(UndergroundBar.place.is_cached(b)) # Reassigning the same value doesn't clear a cached instance. b.place_id = self.p2.pk self.assertTrue(UndergroundBar.place.is_cached(b)) def test_assign_o2o_id_none(self): b = UndergroundBar.objects.create(place=self.p1) b.place_id = None b.save() self.assertIsNone(b.place_id) self.assertFalse(UndergroundBar.place.is_cached(b)) self.assertIsNone(b.place) self.assertTrue(UndergroundBar.place.is_cached(b)) def test_related_object_cache(self): """Regression test for #6886 (the related-object cache)""" # Look up the objects again so that we get "fresh" objects p = Place.objects.get(name="Demon Dogs") r = p.restaurant # Accessing the related object again returns the exactly same object self.assertIs(p.restaurant, r) # But if we kill the cache, we get a new object del p._state.fields_cache["restaurant"] self.assertIsNot(p.restaurant, r) # Reassigning the Restaurant object results in an immediate cache update # We can't use a new Restaurant because that'll violate one-to-one, but # with a new *instance* the is test below will fail if #6886 regresses. r2 = Restaurant.objects.get(pk=r.pk) p.restaurant = r2 self.assertIs(p.restaurant, r2) # Assigning None succeeds if field is null=True. ug_bar = UndergroundBar.objects.create(place=p, serves_cocktails=False) ug_bar.place = None self.assertIsNone(ug_bar.place) # Assigning None will not fail: Place.restaurant is null=False setattr(p, "restaurant", None) # You also can't assign an object of the wrong type here msg = ( 'Cannot assign "": ' '"Place.restaurant" must be a "Restaurant" instance.' ) with self.assertRaisesMessage(ValueError, msg): setattr(p, "restaurant", p) # Creation using keyword argument should cache the related object. p = Place.objects.get(name="Demon Dogs") r = Restaurant(place=p) self.assertIs(r.place, p) # Creation using keyword argument and unsaved related instance (#8070). p = Place() r = Restaurant(place=p) self.assertIs(r.place, p) # Creation using attname keyword argument and an id will cause the related # object to be fetched. p = Place.objects.get(name="Demon Dogs") r = Restaurant(place_id=p.id) self.assertIsNot(r.place, p) self.assertEqual(r.place, p) def test_filter_one_to_one_relations(self): """ Regression test for #9968 filtering reverse one-to-one relations with primary_key=True was misbehaving. We test both (primary_key=True & False) cases here to prevent any reappearance of the problem. """ target = Target.objects.create() self.assertSequenceEqual(Target.objects.filter(pointer=None), [target]) self.assertSequenceEqual(Target.objects.exclude(pointer=None), []) self.assertSequenceEqual(Target.objects.filter(second_pointer=None), [target]) self.assertSequenceEqual(Target.objects.exclude(second_pointer=None), []) def test_o2o_primary_key_delete(self): t = Target.objects.create(name="name") Pointer.objects.create(other=t) num_deleted, objs = Pointer.objects.filter(other__name="name").delete() self.assertEqual(num_deleted, 1) self.assertEqual(objs, {"one_to_one.Pointer": 1}) def test_save_nullable_o2o_after_parent(self): place = Place(name="Rose tattoo") bar = UndergroundBar(place=place) place.save() bar.save() bar.refresh_from_db() self.assertEqual(bar.place, place) def test_reverse_object_does_not_exist_cache(self): """ Regression for #13839 and #17439. DoesNotExist on a reverse one-to-one relation is cached. """ p = Place(name="Zombie Cats", address="Not sure") p.save() with self.assertNumQueries(1): with self.assertRaises(Restaurant.DoesNotExist): p.restaurant with self.assertNumQueries(0): with self.assertRaises(Restaurant.DoesNotExist): p.restaurant def test_reverse_object_cached_when_related_is_accessed(self): """ Regression for #13839 and #17439. The target of a one-to-one relation is cached when the origin is accessed through the reverse relation. """ # Use a fresh object without caches r = Restaurant.objects.get(pk=self.r1.pk) p = r.place with self.assertNumQueries(0): self.assertEqual(p.restaurant, r) def test_related_object_cached_when_reverse_is_accessed(self): """ Regression for #13839 and #17439. The origin of a one-to-one relation is cached when the target is accessed through the reverse relation. """ # Use a fresh object without caches p = Place.objects.get(pk=self.p1.pk) r = p.restaurant with self.assertNumQueries(0): self.assertEqual(r.place, p) def test_reverse_object_cached_when_related_is_set(self): """ Regression for #13839 and #17439. The target of a one-to-one relation is always cached. """ p = Place(name="Zombie Cats", address="Not sure") p.save() self.r1.place = p self.r1.save() with self.assertNumQueries(0): self.assertEqual(p.restaurant, self.r1) def test_reverse_object_cached_when_related_is_unset(self): """ Regression for #13839 and #17439. The target of a one-to-one relation is always cached. """ b = UndergroundBar(place=self.p1, serves_cocktails=True) b.save() with self.assertNumQueries(0): self.assertEqual(self.p1.undergroundbar, b) b.place = None b.save() with self.assertNumQueries(0): with self.assertRaises(UndergroundBar.DoesNotExist): self.p1.undergroundbar def test_get_reverse_on_unsaved_object(self): """ Regression for #18153 and #19089. Accessing the reverse relation on an unsaved object always raises an exception. """ p = Place() # When there's no instance of the origin of the one-to-one with self.assertNumQueries(0): with self.assertRaises(UndergroundBar.DoesNotExist): p.undergroundbar UndergroundBar.objects.create() # When there's one instance of the origin # (p.undergroundbar used to return that instance) with self.assertNumQueries(0): with self.assertRaises(UndergroundBar.DoesNotExist): p.undergroundbar # Several instances of the origin are only possible if database allows # inserting multiple NULL rows for a unique constraint if connection.features.supports_nullable_unique_constraints: UndergroundBar.objects.create() # When there are several instances of the origin with self.assertNumQueries(0): with self.assertRaises(UndergroundBar.DoesNotExist): p.undergroundbar def test_set_reverse_on_unsaved_object(self): """ Writing to the reverse relation on an unsaved object is impossible too. """ p = Place() b = UndergroundBar.objects.create() # Assigning a reverse relation on an unsaved object is allowed. p.undergroundbar = b # However saving the object is not allowed. msg = ( "save() prohibited to prevent data loss due to unsaved related object " "'place'." ) with self.assertNumQueries(0): with self.assertRaisesMessage(ValueError, msg): b.save() def test_nullable_o2o_delete(self): u = UndergroundBar.objects.create(place=self.p1) u.place_id = None u.save() self.p1.delete() self.assertTrue(UndergroundBar.objects.filter(pk=u.pk).exists()) self.assertIsNone(UndergroundBar.objects.get(pk=u.pk).place) def test_hidden_accessor(self): """ When a '+' ending related name is specified no reverse accessor should be added to the related model. """ self.assertFalse( hasattr( Target, HiddenPointer._meta.get_field("target").remote_field.accessor_name, ) ) def test_related_object(self): public_school = School.objects.create(is_public=True) public_director = Director.objects.create(school=public_school, is_temp=False) private_school = School.objects.create(is_public=False) private_director = Director.objects.create(school=private_school, is_temp=True) # Only one school is available via all() due to the custom default manager. self.assertSequenceEqual(School.objects.all(), [public_school]) # Only one director is available via all() due to the custom default manager. self.assertSequenceEqual(Director.objects.all(), [public_director]) self.assertEqual(public_director.school, public_school) self.assertEqual(public_school.director, public_director) # Make sure the base manager is used so that the related objects # is still accessible even if the default manager doesn't normally # allow it. self.assertEqual(private_director.school, private_school) # Make sure the base manager is used so that an student can still access # its related school even if the default manager doesn't normally # allow it. self.assertEqual(private_school.director, private_director) School._meta.base_manager_name = "objects" School._meta._expire_cache() try: private_director = Director._base_manager.get(pk=private_director.pk) with self.assertRaises(School.DoesNotExist): private_director.school finally: School._meta.base_manager_name = None School._meta._expire_cache() Director._meta.base_manager_name = "objects" Director._meta._expire_cache() try: private_school = School._base_manager.get(pk=private_school.pk) with self.assertRaises(Director.DoesNotExist): private_school.director finally: Director._meta.base_manager_name = None Director._meta._expire_cache() def test_create_reverse_o2o_error(self): msg = "The following fields do not exist in this model: restaurant" with self.assertRaisesMessage(ValueError, msg): Place.objects.create(restaurant=self.r1) def test_get_or_create_reverse_o2o_error(self): msg = "The following fields do not exist in this model: restaurant" r2 = Restaurant.objects.create( place=self.p2, serves_hot_dogs=True, serves_pizza=False ) with self.assertRaisesMessage(ValueError, msg): Place.objects.get_or_create(name="nonexistent", defaults={"restaurant": r2}) def test_update_or_create_reverse_o2o_error(self): msg = "The following fields do not exist in this model: restaurant" r2 = Restaurant.objects.create( place=self.p2, serves_hot_dogs=True, serves_pizza=False ) with self.assertRaisesMessage(ValueError, msg): Place.objects.update_or_create( name="nonexistent", defaults={"restaurant": r2} ) def test_hasattr_related_object(self): # The exception raised on attribute access when a related object # doesn't exist should be an instance of a subclass of `AttributeError` # refs #21563 self.assertFalse(hasattr(Director(), "director")) self.assertFalse(hasattr(School(), "school")) def test_update_one_to_one_pk(self): p1 = Place.objects.create() p2 = Place.objects.create() r1 = Restaurant.objects.create(place=p1) r2 = Restaurant.objects.create(place=p2) w = Waiter.objects.create(restaurant=r1) Waiter.objects.update(restaurant=r2) w.refresh_from_db() self.assertEqual(w.restaurant, r2) def test_rel_pk_subquery(self): r = Restaurant.objects.first() q1 = Restaurant.objects.filter(place_id=r.pk) # Subquery using primary key and a query against the # same model works correctly. q2 = Restaurant.objects.filter(place_id__in=q1) self.assertSequenceEqual(q2, [r]) # Subquery using 'pk__in' instead of 'place_id__in' work, too. q2 = Restaurant.objects.filter( pk__in=Restaurant.objects.filter(place__id=r.place.pk) ) self.assertSequenceEqual(q2, [r]) q3 = Restaurant.objects.filter(place__in=Place.objects.all()) self.assertSequenceEqual(q3, [r]) q4 = Restaurant.objects.filter(place__in=Place.objects.filter(id=r.pk)) self.assertSequenceEqual(q4, [r]) def test_rel_pk_exact(self): r = Restaurant.objects.first() r2 = Restaurant.objects.filter(pk__exact=r).first() self.assertEqual(r, r2) def test_primary_key_to_field_filter(self): target = Target.objects.create(name="foo") pointer = ToFieldPointer.objects.create(target=target) self.assertSequenceEqual( ToFieldPointer.objects.filter(target=target), [pointer] ) self.assertSequenceEqual( ToFieldPointer.objects.filter(pk__exact=pointer), [pointer] ) def test_cached_relation_invalidated_on_save(self): """ Model.save() invalidates stale OneToOneField relations after a primary key assignment. """ self.assertEqual(self.b1.place, self.p1) # caches b1.place self.b1.place_id = self.p2.pk self.b1.save() self.assertEqual(self.b1.place, self.p2) def test_get_prefetch_queryset_warning(self): places = Place.objects.all() msg = ( "get_prefetch_queryset() is deprecated. Use get_prefetch_querysets() " "instead." ) with self.assertWarnsMessage(RemovedInDjango60Warning, msg) as ctx: Place.bar.get_prefetch_queryset(places) self.assertEqual(ctx.filename, __file__) def test_get_prefetch_querysets_invalid_querysets_length(self): places = Place.objects.all() msg = ( "querysets argument of get_prefetch_querysets() should have a length of 1." ) with self.assertRaisesMessage(ValueError, msg): Place.bar.get_prefetch_querysets( instances=places, querysets=[Bar.objects.all(), Bar.objects.all()], )