from operator import attrgetter from unittest import skipUnless from django.core.exceptions import FieldError, ValidationError from django.db import connection, models from django.test import SimpleTestCase, TestCase from django.test.utils import CaptureQueriesContext, isolate_apps from django.utils.version import PY37 from .models import ( Base, Chef, CommonInfo, GrandChild, GrandParent, ItalianRestaurant, MixinModel, Parent, ParkingLot, Place, Post, Restaurant, Student, SubBase, Supplier, Title, Worker, ) class ModelInheritanceTests(TestCase): def test_abstract(self): # The Student and Worker models both have 'name' and 'age' fields on # them and inherit the __str__() method, just as with normal Python # subclassing. This is useful if you want to factor out common # information for programming purposes, but still completely # independent separate models at the database level. w1 = Worker.objects.create(name="Fred", age=35, job="Quarry worker") Worker.objects.create(name="Barney", age=34, job="Quarry worker") s = Student.objects.create(name="Pebbles", age=5, school_class="1B") self.assertEqual(str(w1), "Worker Fred") self.assertEqual(str(s), "Student Pebbles") # The children inherit the Meta class of their parents (if they don't # specify their own). self.assertSequenceEqual( Worker.objects.values("name"), [ {"name": "Barney"}, {"name": "Fred"}, ], ) # Since Student does not subclass CommonInfo's Meta, it has the effect # of completely overriding it. So ordering by name doesn't take place # for Students. self.assertEqual(Student._meta.ordering, []) # However, the CommonInfo class cannot be used as a normal model (it # doesn't exist as a model). with self.assertRaisesMessage(AttributeError, "'CommonInfo' has no attribute 'objects'"): CommonInfo.objects.all() def test_reverse_relation_for_different_hierarchy_tree(self): # Even though p.supplier for a Place 'p' (a parent of a Supplier), a # Restaurant object cannot access that reverse relation, since it's not # part of the Place-Supplier Hierarchy. self.assertQuerysetEqual(Place.objects.filter(supplier__name="foo"), []) msg = ( "Cannot resolve keyword 'supplier' into field. Choices are: " "address, chef, chef_id, id, italianrestaurant, lot, name, " "place_ptr, place_ptr_id, provider, rating, serves_hot_dogs, serves_pizza" ) with self.assertRaisesMessage(FieldError, msg): Restaurant.objects.filter(supplier__name="foo") def test_model_with_distinct_accessors(self): # The Post model has distinct accessors for the Comment and Link models. post = Post.objects.create(title="Lorem Ipsum") post.attached_comment_set.create(content="Save $ on V1agr@", is_spam=True) post.attached_link_set.create( content="The Web framework for perfections with deadlines.", url="http://www.djangoproject.com/" ) # The Post model doesn't have an attribute called # 'attached_%(class)s_set'. msg = "'Post' object has no attribute 'attached_%(class)s_set'" with self.assertRaisesMessage(AttributeError, msg): getattr(post, "attached_%(class)s_set") def test_model_with_distinct_related_query_name(self): self.assertQuerysetEqual(Post.objects.filter(attached_model_inheritance_comments__is_spam=True), []) # The Post model doesn't have a related query accessor based on # related_name (attached_comment_set). msg = "Cannot resolve keyword 'attached_comment_set' into field." with self.assertRaisesMessage(FieldError, msg): Post.objects.filter(attached_comment_set__is_spam=True) def test_meta_fields_and_ordering(self): # Make sure Restaurant and ItalianRestaurant have the right fields in # the right order. self.assertEqual( [f.name for f in Restaurant._meta.fields], ["id", "name", "address", "place_ptr", "rating", "serves_hot_dogs", "serves_pizza", "chef"] ) self.assertEqual( [f.name for f in ItalianRestaurant._meta.fields], ["id", "name", "address", "place_ptr", "rating", "serves_hot_dogs", "serves_pizza", "chef", "restaurant_ptr", "serves_gnocchi"], ) self.assertEqual(Restaurant._meta.ordering, ["-rating"]) def test_custompk_m2m(self): b = Base.objects.create() b.titles.add(Title.objects.create(title="foof")) s = SubBase.objects.create(sub_id=b.id) b = Base.objects.get(pk=s.id) self.assertNotEqual(b.pk, s.pk) # Low-level test for related_val self.assertEqual(s.titles.related_val, (s.id,)) # Higher level test for correct query values (title foof not # accidentally found). self.assertQuerysetEqual(s.titles.all(), []) def test_update_parent_filtering(self): """ Updating a field of a model subclass doesn't issue an UPDATE query constrained by an inner query (#10399). """ supplier = Supplier.objects.create( name='Central market', address='610 some street', ) # Capture the expected query in a database agnostic way with CaptureQueriesContext(connection) as captured_queries: Place.objects.filter(pk=supplier.pk).update(name=supplier.name) expected_sql = captured_queries[0]['sql'] # Capture the queries executed when a subclassed model instance is saved. with CaptureQueriesContext(connection) as captured_queries: supplier.save(update_fields=('name',)) for query in captured_queries: sql = query['sql'] if 'UPDATE' in sql: self.assertEqual(expected_sql, sql) def test_create_child_no_update(self): """Creating a child with non-abstract parents only issues INSERTs.""" def a(): GrandChild.objects.create( email='grand_parent@example.com', first_name='grand', last_name='parent', ) def b(): GrandChild().save() for i, test in enumerate([a, b]): with self.subTest(i=i), self.assertNumQueries(4), CaptureQueriesContext(connection) as queries: test() for query in queries: sql = query['sql'] self.assertIn('INSERT INTO', sql, sql) def test_eq(self): # Equality doesn't transfer in multitable inheritance. self.assertNotEqual(Place(id=1), Restaurant(id=1)) self.assertNotEqual(Restaurant(id=1), Place(id=1)) def test_mixin_init(self): m = MixinModel() self.assertEqual(m.other_attr, 1) @isolate_apps('model_inheritance') def test_abstract_parent_link(self): class A(models.Model): pass class B(A): a = models.OneToOneField('A', parent_link=True, on_delete=models.CASCADE) class Meta: abstract = True class C(B): pass self.assertIs(C._meta.parents[A], C._meta.get_field('a')) @isolate_apps('model_inheritance') def test_init_subclass(self): saved_kwargs = {} class A(models.Model): def __init_subclass__(cls, **kwargs): super().__init_subclass__() saved_kwargs.update(kwargs) kwargs = {'x': 1, 'y': 2, 'z': 3} class B(A, **kwargs): pass self.assertEqual(saved_kwargs, kwargs) @isolate_apps('model_inheritance') def test_set_name(self): class ClassAttr: called = None def __set_name__(self_, owner, name): self.assertIsNone(self_.called) self_.called = (owner, name) class A(models.Model): attr = ClassAttr() self.assertEqual(A.attr.called, (A, 'attr')) def test_inherited_ordering_pk_desc(self): p1 = Parent.objects.create(first_name='Joe', email='joe@email.com') p2 = Parent.objects.create(first_name='Jon', email='jon@email.com') expected_order_by_sql = 'ORDER BY %s.%s DESC' % ( connection.ops.quote_name(Parent._meta.db_table), connection.ops.quote_name( Parent._meta.get_field('grandparent_ptr').column ), ) qs = Parent.objects.all() self.assertSequenceEqual(qs, [p2, p1]) self.assertIn(expected_order_by_sql, str(qs.query)) @skipUnless(PY37, '__class_getitem__() was added in Python 3.7') def test_queryset_class_getitem(self): self.assertIs(models.QuerySet[Post], models.QuerySet) self.assertIs(models.QuerySet[Post, Post], models.QuerySet) self.assertIs(models.QuerySet[Post, int, str], models.QuerySet) class ModelInheritanceDataTests(TestCase): @classmethod def setUpTestData(cls): cls.restaurant = Restaurant.objects.create( name="Demon Dogs", address="944 W. Fullerton", serves_hot_dogs=True, serves_pizza=False, rating=2, ) chef = Chef.objects.create(name="Albert") cls.italian_restaurant = ItalianRestaurant.objects.create( name="Ristorante Miron", address="1234 W. Ash", serves_hot_dogs=False, serves_pizza=False, serves_gnocchi=True, rating=4, chef=chef, ) def test_filter_inherited_model(self): self.assertQuerysetEqual( ItalianRestaurant.objects.filter(address="1234 W. Ash"), [ "Ristorante Miron", ], attrgetter("name") ) def test_update_inherited_model(self): self.italian_restaurant.address = "1234 W. Elm" self.italian_restaurant.save() self.assertQuerysetEqual( ItalianRestaurant.objects.filter(address="1234 W. Elm"), [ "Ristorante Miron", ], attrgetter("name") ) def test_parent_fields_available_for_filtering_in_child_model(self): # Parent fields can be used directly in filters on the child model. self.assertQuerysetEqual( Restaurant.objects.filter(name="Demon Dogs"), [ "Demon Dogs", ], attrgetter("name") ) self.assertQuerysetEqual( ItalianRestaurant.objects.filter(address="1234 W. Ash"), [ "Ristorante Miron", ], attrgetter("name") ) def test_filter_on_parent_returns_object_of_parent_type(self): # Filters against the parent model return objects of the parent's type. p = Place.objects.get(name="Demon Dogs") self.assertIs(type(p), Place) def test_parent_child_one_to_one_link(self): # Since the parent and child are linked by an automatically created # OneToOneField, you can get from the parent to the child by using the # child's name. self.assertEqual( Place.objects.get(name="Demon Dogs").restaurant, Restaurant.objects.get(name="Demon Dogs") ) self.assertEqual( Place.objects.get(name="Ristorante Miron").restaurant.italianrestaurant, ItalianRestaurant.objects.get(name="Ristorante Miron") ) self.assertEqual( Restaurant.objects.get(name="Ristorante Miron").italianrestaurant, ItalianRestaurant.objects.get(name="Ristorante Miron") ) def test_parent_child_one_to_one_link_on_nonrelated_objects(self): # This won't work because the Demon Dogs restaurant is not an Italian # restaurant. with self.assertRaises(ItalianRestaurant.DoesNotExist): Place.objects.get(name="Demon Dogs").restaurant.italianrestaurant def test_inherited_does_not_exist_exception(self): # An ItalianRestaurant which does not exist is also a Place which does # not exist. with self.assertRaises(Place.DoesNotExist): ItalianRestaurant.objects.get(name="The Noodle Void") def test_inherited_multiple_objects_returned_exception(self): # MultipleObjectsReturned is also inherited. with self.assertRaises(Place.MultipleObjectsReturned): Restaurant.objects.get() def test_related_objects_for_inherited_models(self): # Related objects work just as they normally do. s1 = Supplier.objects.create(name="Joe's Chickens", address="123 Sesame St") s1.customers.set([self.restaurant, self.italian_restaurant]) s2 = Supplier.objects.create(name="Luigi's Pasta", address="456 Sesame St") s2.customers.set([self.italian_restaurant]) # This won't work because the Place we select is not a Restaurant (it's # a Supplier). p = Place.objects.get(name="Joe's Chickens") with self.assertRaises(Restaurant.DoesNotExist): p.restaurant self.assertEqual(p.supplier, s1) self.assertQuerysetEqual( self.italian_restaurant.provider.order_by("-name"), [ "Luigi's Pasta", "Joe's Chickens" ], attrgetter("name") ) self.assertQuerysetEqual( Restaurant.objects.filter(provider__name__contains="Chickens"), [ "Ristorante Miron", "Demon Dogs", ], attrgetter("name") ) self.assertQuerysetEqual( ItalianRestaurant.objects.filter(provider__name__contains="Chickens"), [ "Ristorante Miron", ], attrgetter("name"), ) ParkingLot.objects.create( name="Main St", address="111 Main St", main_site=s1 ) ParkingLot.objects.create( name="Well Lit", address="124 Sesame St", main_site=self.italian_restaurant ) self.assertEqual( Restaurant.objects.get(lot__name="Well Lit").name, "Ristorante Miron" ) def test_update_works_on_parent_and_child_models_at_once(self): # The update() command can update fields in parent and child classes at # once (although it executed multiple SQL queries to do so). rows = Restaurant.objects.filter( serves_hot_dogs=True, name__contains="D" ).update( name="Demon Puppies", serves_hot_dogs=False ) self.assertEqual(rows, 1) r1 = Restaurant.objects.get(pk=self.restaurant.pk) self.assertFalse(r1.serves_hot_dogs) self.assertEqual(r1.name, "Demon Puppies") def test_values_works_on_parent_model_fields(self): # The values() command also works on fields from parent models. self.assertSequenceEqual( ItalianRestaurant.objects.values("name", "rating"), [ {"rating": 4, "name": "Ristorante Miron"}, ], ) def test_select_related_works_on_parent_model_fields(self): # select_related works with fields from the parent object as if they # were a normal part of the model. self.assertNumQueries( 2, lambda: ItalianRestaurant.objects.all()[0].chef ) self.assertNumQueries( 1, lambda: ItalianRestaurant.objects.select_related("chef")[0].chef ) def test_select_related_defer(self): """ #23370 - Should be able to defer child fields when using select_related() from parent to child. """ qs = (Restaurant.objects.select_related("italianrestaurant") .defer("italianrestaurant__serves_gnocchi").order_by("rating")) # The field was actually deferred with self.assertNumQueries(2): objs = list(qs.all()) self.assertTrue(objs[1].italianrestaurant.serves_gnocchi) # Model fields where assigned correct values self.assertEqual(qs[0].name, 'Demon Dogs') self.assertEqual(qs[0].rating, 2) self.assertEqual(qs[1].italianrestaurant.name, 'Ristorante Miron') self.assertEqual(qs[1].italianrestaurant.rating, 4) def test_parent_cache_reuse(self): place = Place.objects.create() GrandChild.objects.create(place=place) grand_parent = GrandParent.objects.latest('pk') with self.assertNumQueries(1): self.assertEqual(grand_parent.place, place) parent = grand_parent.parent with self.assertNumQueries(0): self.assertEqual(parent.place, place) child = parent.child with self.assertNumQueries(0): self.assertEqual(child.place, place) grandchild = child.grandchild with self.assertNumQueries(0): self.assertEqual(grandchild.place, place) def test_update_query_counts(self): """ Update queries do not generate unnecessary queries (#18304). """ with self.assertNumQueries(3): self.italian_restaurant.save() def test_filter_inherited_on_null(self): # Refs #12567 Supplier.objects.create( name="Central market", address="610 some street", ) self.assertQuerysetEqual( Place.objects.filter(supplier__isnull=False), [ "Central market", ], attrgetter("name") ) self.assertQuerysetEqual( Place.objects.filter(supplier__isnull=True).order_by("name"), [ "Demon Dogs", "Ristorante Miron", ], attrgetter("name") ) def test_exclude_inherited_on_null(self): # Refs #12567 Supplier.objects.create( name="Central market", address="610 some street", ) self.assertQuerysetEqual( Place.objects.exclude(supplier__isnull=False).order_by("name"), [ "Demon Dogs", "Ristorante Miron", ], attrgetter("name") ) self.assertQuerysetEqual( Place.objects.exclude(supplier__isnull=True), [ "Central market", ], attrgetter("name") ) @isolate_apps('model_inheritance', 'model_inheritance.tests') class InheritanceSameModelNameTests(SimpleTestCase): def test_abstract_fk_related_name(self): related_name = '%(app_label)s_%(class)s_references' class Referenced(models.Model): class Meta: app_label = 'model_inheritance' class AbstractReferent(models.Model): reference = models.ForeignKey(Referenced, models.CASCADE, related_name=related_name) class Meta: app_label = 'model_inheritance' abstract = True class Referent(AbstractReferent): class Meta: app_label = 'model_inheritance' LocalReferent = Referent class Referent(AbstractReferent): class Meta: app_label = 'tests' ForeignReferent = Referent self.assertFalse(hasattr(Referenced, related_name)) self.assertIs(Referenced.model_inheritance_referent_references.field.model, LocalReferent) self.assertIs(Referenced.tests_referent_references.field.model, ForeignReferent) class InheritanceUniqueTests(TestCase): @classmethod def setUpTestData(cls): cls.grand_parent = GrandParent.objects.create( email='grand_parent@example.com', first_name='grand', last_name='parent', ) def test_unique(self): grand_child = GrandChild( email=self.grand_parent.email, first_name='grand', last_name='child', ) msg = 'Grand parent with this Email already exists.' with self.assertRaisesMessage(ValidationError, msg): grand_child.validate_unique() def test_unique_together(self): grand_child = GrandChild( email='grand_child@example.com', first_name=self.grand_parent.first_name, last_name=self.grand_parent.last_name, ) msg = 'Grand parent with this First name and Last name already exists.' with self.assertRaisesMessage(ValidationError, msg): grand_child.validate_unique()