django/tests/model_inheritance/tests.py

514 lines
19 KiB
Python

import unittest
from operator import attrgetter
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 PY36
from .models import (
Base, Chef, CommonInfo, GrandChild, GrandParent, ItalianRestaurant,
MixinModel, 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'))
@unittest.skipUnless(PY36, 'init_subclass is new in Python 3.6')
@isolate_apps('model_inheritance')
def test_init_subclass(self):
saved_kwargs = {}
class A:
def __init_subclass__(cls, **kwargs):
super().__init_subclass__()
saved_kwargs.update(kwargs)
kwargs = {'x': 1, 'y': 2, 'z': 3}
class B(A, models.Model, **kwargs):
pass
self.assertEqual(saved_kwargs, kwargs)
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()