Viewing github.com/django/django-stable-4.1.x/tests/model

```
from operator import attrgetter
```

from django.core.exceptions import FieldError, ValidationError

from django.db import connection, models

from django.db.models.query_utils import DeferredAttribute

from django.test import SimpleTestCase, TestCase

from django.test.utils import CaptureQueriesContext, isolate_apps

```
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="[email protected]",

```
                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="[email protected]")

        p2 = Parent.objects.create(first_name="Jon", email="[email protected]")

        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))

    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)

    def test_shadow_parent_attribute_with_field(self):

        class ScalarParent(models.Model):

```
            foo = 1
```

        class ScalarOverride(ScalarParent):

            foo = models.IntegerField()

        self.assertEqual(type(ScalarOverride.foo), DeferredAttribute)

    def test_shadow_parent_property_with_field(self):

        class PropertyParent(models.Model):

```
            @property
```
```
            def foo(self):
```
```
                pass
```

        class PropertyOverride(PropertyParent):

            foo = models.IntegerField()

        self.assertEqual(type(PropertyOverride.foo), DeferredAttribute)

    def test_shadow_parent_method_with_field(self):

        class MethodParent(models.Model):

```
            def foo(self):
```
```
                pass
```

        class MethodOverride(MethodParent):

            foo = models.IntegerField()

        self.assertEqual(type(MethodOverride.foo), DeferredAttribute)

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="[email protected]",

```
            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="[email protected]",

            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()