django/tests/multiple_database/tests.py

2079 lines
92 KiB
Python

from __future__ import unicode_literals
import datetime
import pickle
import warnings
from operator import attrgetter
from django.contrib.auth.models import User
from django.contrib.contenttypes.models import ContentType
from django.core import management
from django.db import DEFAULT_DB_ALIAS, connections, router, transaction
from django.db.models import signals
from django.db.utils import ConnectionRouter
from django.test import TestCase, override_settings
from django.utils.encoding import force_text
from django.utils.six import StringIO
from .models import Book, Person, Pet, Review, UserProfile
from .routers import AuthRouter, TestRouter, WriteRouter
class QueryTestCase(TestCase):
multi_db = True
def test_db_selection(self):
"Check that querysets will use the default database by default"
self.assertEqual(Book.objects.db, DEFAULT_DB_ALIAS)
self.assertEqual(Book.objects.all().db, DEFAULT_DB_ALIAS)
self.assertEqual(Book.objects.using('other').db, 'other')
self.assertEqual(Book.objects.db_manager('other').db, 'other')
self.assertEqual(Book.objects.db_manager('other').all().db, 'other')
def test_default_creation(self):
"Objects created on the default database don't leak onto other databases"
# Create a book on the default database using create()
Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
# Create a book on the default database using a save
dive = Book()
dive.title = "Dive into Python"
dive.published = datetime.date(2009, 5, 4)
dive.save()
# Check that book exists on the default database, but not on other database
try:
Book.objects.get(title="Pro Django")
Book.objects.using('default').get(title="Pro Django")
except Book.DoesNotExist:
self.fail('"Pro Django" should exist on default database')
self.assertRaises(
Book.DoesNotExist,
Book.objects.using('other').get,
title="Pro Django"
)
try:
Book.objects.get(title="Dive into Python")
Book.objects.using('default').get(title="Dive into Python")
except Book.DoesNotExist:
self.fail('"Dive into Python" should exist on default database')
self.assertRaises(
Book.DoesNotExist,
Book.objects.using('other').get,
title="Dive into Python"
)
def test_other_creation(self):
"Objects created on another database don't leak onto the default database"
# Create a book on the second database
Book.objects.using('other').create(title="Pro Django",
published=datetime.date(2008, 12, 16))
# Create a book on the default database using a save
dive = Book()
dive.title = "Dive into Python"
dive.published = datetime.date(2009, 5, 4)
dive.save(using='other')
# Check that book exists on the default database, but not on other database
try:
Book.objects.using('other').get(title="Pro Django")
except Book.DoesNotExist:
self.fail('"Pro Django" should exist on other database')
self.assertRaises(
Book.DoesNotExist,
Book.objects.get,
title="Pro Django"
)
self.assertRaises(
Book.DoesNotExist,
Book.objects.using('default').get,
title="Pro Django"
)
try:
Book.objects.using('other').get(title="Dive into Python")
except Book.DoesNotExist:
self.fail('"Dive into Python" should exist on other database')
self.assertRaises(
Book.DoesNotExist,
Book.objects.get,
title="Dive into Python"
)
self.assertRaises(
Book.DoesNotExist,
Book.objects.using('default').get,
title="Dive into Python"
)
def test_refresh(self):
dive = Book()
dive.title = "Dive into Python"
dive = Book()
dive.title = "Dive into Python"
dive.published = datetime.date(2009, 5, 4)
dive.save(using='other')
dive.published = datetime.date(2009, 5, 4)
dive.save(using='other')
dive2 = Book.objects.using('other').get()
dive2.title = "Dive into Python (on default)"
dive2.save(using='default')
dive.refresh_from_db()
self.assertEqual(dive.title, "Dive into Python")
dive.refresh_from_db(using='default')
self.assertEqual(dive.title, "Dive into Python (on default)")
self.assertEqual(dive._state.db, "default")
def test_basic_queries(self):
"Queries are constrained to a single database"
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
dive = Book.objects.using('other').get(published=datetime.date(2009, 5, 4))
self.assertEqual(dive.title, "Dive into Python")
self.assertRaises(Book.DoesNotExist, Book.objects.using('default').get, published=datetime.date(2009, 5, 4))
dive = Book.objects.using('other').get(title__icontains="dive")
self.assertEqual(dive.title, "Dive into Python")
self.assertRaises(Book.DoesNotExist, Book.objects.using('default').get, title__icontains="dive")
dive = Book.objects.using('other').get(title__iexact="dive INTO python")
self.assertEqual(dive.title, "Dive into Python")
self.assertRaises(Book.DoesNotExist, Book.objects.using('default').get, title__iexact="dive INTO python")
dive = Book.objects.using('other').get(published__year=2009)
self.assertEqual(dive.title, "Dive into Python")
self.assertEqual(dive.published, datetime.date(2009, 5, 4))
self.assertRaises(Book.DoesNotExist, Book.objects.using('default').get, published__year=2009)
years = Book.objects.using('other').dates('published', 'year')
self.assertEqual([o.year for o in years], [2009])
years = Book.objects.using('default').dates('published', 'year')
self.assertEqual([o.year for o in years], [])
months = Book.objects.using('other').dates('published', 'month')
self.assertEqual([o.month for o in months], [5])
months = Book.objects.using('default').dates('published', 'month')
self.assertEqual([o.month for o in months], [])
def test_m2m_separation(self):
"M2M fields are constrained to a single database"
# Create a book and author on the default database
pro = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
marty = Person.objects.create(name="Marty Alchin")
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
mark = Person.objects.using('other').create(name="Mark Pilgrim")
# Save the author relations
pro.authors = [marty]
dive.authors = [mark]
# Inspect the m2m tables directly.
# There should be 1 entry in each database
self.assertEqual(Book.authors.through.objects.using('default').count(), 1)
self.assertEqual(Book.authors.through.objects.using('other').count(), 1)
# Check that queries work across m2m joins
self.assertEqual(list(Book.objects.using('default').filter(authors__name='Marty Alchin').values_list('title', flat=True)),
['Pro Django'])
self.assertEqual(list(Book.objects.using('other').filter(authors__name='Marty Alchin').values_list('title', flat=True)),
[])
self.assertEqual(list(Book.objects.using('default').filter(authors__name='Mark Pilgrim').values_list('title', flat=True)),
[])
self.assertEqual(list(Book.objects.using('other').filter(authors__name='Mark Pilgrim').values_list('title', flat=True)),
['Dive into Python'])
# Reget the objects to clear caches
dive = Book.objects.using('other').get(title="Dive into Python")
mark = Person.objects.using('other').get(name="Mark Pilgrim")
# Retrieve related object by descriptor. Related objects should be database-bound
self.assertEqual(list(dive.authors.all().values_list('name', flat=True)),
['Mark Pilgrim'])
self.assertEqual(list(mark.book_set.all().values_list('title', flat=True)),
['Dive into Python'])
def test_m2m_forward_operations(self):
"M2M forward manipulations are all constrained to a single DB"
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
mark = Person.objects.using('other').create(name="Mark Pilgrim")
# Save the author relations
dive.authors = [mark]
# Add a second author
john = Person.objects.using('other').create(name="John Smith")
self.assertEqual(list(Book.objects.using('other').filter(authors__name='John Smith').values_list('title', flat=True)),
[])
dive.authors.add(john)
self.assertEqual(list(Book.objects.using('other').filter(authors__name='Mark Pilgrim').values_list('title', flat=True)),
['Dive into Python'])
self.assertEqual(list(Book.objects.using('other').filter(authors__name='John Smith').values_list('title', flat=True)),
['Dive into Python'])
# Remove the second author
dive.authors.remove(john)
self.assertEqual(list(Book.objects.using('other').filter(authors__name='Mark Pilgrim').values_list('title', flat=True)),
['Dive into Python'])
self.assertEqual(list(Book.objects.using('other').filter(authors__name='John Smith').values_list('title', flat=True)),
[])
# Clear all authors
dive.authors.clear()
self.assertEqual(list(Book.objects.using('other').filter(authors__name='Mark Pilgrim').values_list('title', flat=True)),
[])
self.assertEqual(list(Book.objects.using('other').filter(authors__name='John Smith').values_list('title', flat=True)),
[])
# Create an author through the m2m interface
dive.authors.create(name='Jane Brown')
self.assertEqual(list(Book.objects.using('other').filter(authors__name='Mark Pilgrim').values_list('title', flat=True)),
[])
self.assertEqual(list(Book.objects.using('other').filter(authors__name='Jane Brown').values_list('title', flat=True)),
['Dive into Python'])
def test_m2m_reverse_operations(self):
"M2M reverse manipulations are all constrained to a single DB"
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
mark = Person.objects.using('other').create(name="Mark Pilgrim")
# Save the author relations
dive.authors = [mark]
# Create a second book on the other database
grease = Book.objects.using('other').create(title="Greasemonkey Hacks",
published=datetime.date(2005, 11, 1))
# Add a books to the m2m
mark.book_set.add(grease)
self.assertEqual(list(Person.objects.using('other').filter(book__title='Dive into Python').values_list('name', flat=True)),
['Mark Pilgrim'])
self.assertEqual(list(Person.objects.using('other').filter(book__title='Greasemonkey Hacks').values_list('name', flat=True)),
['Mark Pilgrim'])
# Remove a book from the m2m
mark.book_set.remove(grease)
self.assertEqual(list(Person.objects.using('other').filter(book__title='Dive into Python').values_list('name', flat=True)),
['Mark Pilgrim'])
self.assertEqual(list(Person.objects.using('other').filter(book__title='Greasemonkey Hacks').values_list('name', flat=True)),
[])
# Clear the books associated with mark
mark.book_set.clear()
self.assertEqual(list(Person.objects.using('other').filter(book__title='Dive into Python').values_list('name', flat=True)),
[])
self.assertEqual(list(Person.objects.using('other').filter(book__title='Greasemonkey Hacks').values_list('name', flat=True)),
[])
# Create a book through the m2m interface
mark.book_set.create(title="Dive into HTML5", published=datetime.date(2020, 1, 1))
self.assertEqual(list(Person.objects.using('other').filter(book__title='Dive into Python').values_list('name', flat=True)),
[])
self.assertEqual(list(Person.objects.using('other').filter(book__title='Dive into HTML5').values_list('name', flat=True)),
['Mark Pilgrim'])
def test_m2m_cross_database_protection(self):
"Operations that involve sharing M2M objects across databases raise an error"
# Create a book and author on the default database
pro = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
marty = Person.objects.create(name="Marty Alchin")
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
mark = Person.objects.using('other').create(name="Mark Pilgrim")
# Set a foreign key set with an object from a different database
with self.assertRaises(ValueError):
with transaction.atomic(using='default'):
marty.edited = [pro, dive]
# Add to an m2m with an object from a different database
with self.assertRaises(ValueError):
with transaction.atomic(using='default'):
marty.book_set.add(dive)
# Set a m2m with an object from a different database
with self.assertRaises(ValueError):
with transaction.atomic(using='default'):
marty.book_set = [pro, dive]
# Add to a reverse m2m with an object from a different database
with self.assertRaises(ValueError):
with transaction.atomic(using='other'):
dive.authors.add(marty)
# Set a reverse m2m with an object from a different database
with self.assertRaises(ValueError):
with transaction.atomic(using='other'):
dive.authors = [mark, marty]
def test_m2m_deletion(self):
"Cascaded deletions of m2m relations issue queries on the right database"
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
mark = Person.objects.using('other').create(name="Mark Pilgrim")
dive.authors = [mark]
# Check the initial state
self.assertEqual(Person.objects.using('default').count(), 0)
self.assertEqual(Book.objects.using('default').count(), 0)
self.assertEqual(Book.authors.through.objects.using('default').count(), 0)
self.assertEqual(Person.objects.using('other').count(), 1)
self.assertEqual(Book.objects.using('other').count(), 1)
self.assertEqual(Book.authors.through.objects.using('other').count(), 1)
# Delete the object on the other database
dive.delete(using='other')
self.assertEqual(Person.objects.using('default').count(), 0)
self.assertEqual(Book.objects.using('default').count(), 0)
self.assertEqual(Book.authors.through.objects.using('default').count(), 0)
# The person still exists ...
self.assertEqual(Person.objects.using('other').count(), 1)
# ... but the book has been deleted
self.assertEqual(Book.objects.using('other').count(), 0)
# ... and the relationship object has also been deleted.
self.assertEqual(Book.authors.through.objects.using('other').count(), 0)
# Now try deletion in the reverse direction. Set up the relation again
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
dive.authors = [mark]
# Check the initial state
self.assertEqual(Person.objects.using('default').count(), 0)
self.assertEqual(Book.objects.using('default').count(), 0)
self.assertEqual(Book.authors.through.objects.using('default').count(), 0)
self.assertEqual(Person.objects.using('other').count(), 1)
self.assertEqual(Book.objects.using('other').count(), 1)
self.assertEqual(Book.authors.through.objects.using('other').count(), 1)
# Delete the object on the other database
mark.delete(using='other')
self.assertEqual(Person.objects.using('default').count(), 0)
self.assertEqual(Book.objects.using('default').count(), 0)
self.assertEqual(Book.authors.through.objects.using('default').count(), 0)
# The person has been deleted ...
self.assertEqual(Person.objects.using('other').count(), 0)
# ... but the book still exists
self.assertEqual(Book.objects.using('other').count(), 1)
# ... and the relationship object has been deleted.
self.assertEqual(Book.authors.through.objects.using('other').count(), 0)
def test_foreign_key_separation(self):
"FK fields are constrained to a single database"
# Create a book and author on the default database
pro = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
george = Person.objects.create(name="George Vilches")
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
chris = Person.objects.using('other').create(name="Chris Mills")
# Save the author's favorite books
pro.editor = george
pro.save()
dive.editor = chris
dive.save()
pro = Book.objects.using('default').get(title="Pro Django")
self.assertEqual(pro.editor.name, "George Vilches")
dive = Book.objects.using('other').get(title="Dive into Python")
self.assertEqual(dive.editor.name, "Chris Mills")
# Check that queries work across foreign key joins
self.assertEqual(list(Person.objects.using('default').filter(edited__title='Pro Django').values_list('name', flat=True)),
['George Vilches'])
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Pro Django').values_list('name', flat=True)),
[])
self.assertEqual(list(Person.objects.using('default').filter(edited__title='Dive into Python').values_list('name', flat=True)),
[])
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into Python').values_list('name', flat=True)),
['Chris Mills'])
# Reget the objects to clear caches
chris = Person.objects.using('other').get(name="Chris Mills")
dive = Book.objects.using('other').get(title="Dive into Python")
# Retrieve related object by descriptor. Related objects should be database-bound
self.assertEqual(list(chris.edited.values_list('title', flat=True)),
['Dive into Python'])
def test_foreign_key_reverse_operations(self):
"FK reverse manipulations are all constrained to a single DB"
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
chris = Person.objects.using('other').create(name="Chris Mills")
# Save the author relations
dive.editor = chris
dive.save()
# Add a second book edited by chris
html5 = Book.objects.using('other').create(title="Dive into HTML5", published=datetime.date(2010, 3, 15))
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into HTML5').values_list('name', flat=True)),
[])
chris.edited.add(html5)
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into HTML5').values_list('name', flat=True)),
['Chris Mills'])
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into Python').values_list('name', flat=True)),
['Chris Mills'])
# Remove the second editor
chris.edited.remove(html5)
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into HTML5').values_list('name', flat=True)),
[])
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into Python').values_list('name', flat=True)),
['Chris Mills'])
# Clear all edited books
chris.edited.clear()
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into HTML5').values_list('name', flat=True)),
[])
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into Python').values_list('name', flat=True)),
[])
# Create an author through the m2m interface
chris.edited.create(title='Dive into Water', published=datetime.date(2010, 3, 15))
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into HTML5').values_list('name', flat=True)),
[])
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into Water').values_list('name', flat=True)),
['Chris Mills'])
self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into Python').values_list('name', flat=True)),
[])
def test_foreign_key_cross_database_protection(self):
"Operations that involve sharing FK objects across databases raise an error"
# Create a book and author on the default database
pro = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
marty = Person.objects.create(name="Marty Alchin")
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
# Set a foreign key with an object from a different database
with self.assertRaises(ValueError):
dive.editor = marty
# Set a foreign key set with an object from a different database
with self.assertRaises(ValueError):
with transaction.atomic(using='default'):
marty.edited = [pro, dive]
# Add to a foreign key set with an object from a different database
with self.assertRaises(ValueError):
with transaction.atomic(using='default'):
marty.edited.add(dive)
def test_foreign_key_deletion(self):
"Cascaded deletions of Foreign Key relations issue queries on the right database"
mark = Person.objects.using('other').create(name="Mark Pilgrim")
Pet.objects.using('other').create(name="Fido", owner=mark)
# Check the initial state
self.assertEqual(Person.objects.using('default').count(), 0)
self.assertEqual(Pet.objects.using('default').count(), 0)
self.assertEqual(Person.objects.using('other').count(), 1)
self.assertEqual(Pet.objects.using('other').count(), 1)
# Delete the person object, which will cascade onto the pet
mark.delete(using='other')
self.assertEqual(Person.objects.using('default').count(), 0)
self.assertEqual(Pet.objects.using('default').count(), 0)
# Both the pet and the person have been deleted from the right database
self.assertEqual(Person.objects.using('other').count(), 0)
self.assertEqual(Pet.objects.using('other').count(), 0)
def test_foreign_key_validation(self):
"ForeignKey.validate() uses the correct database"
mickey = Person.objects.using('other').create(name="Mickey")
pluto = Pet.objects.using('other').create(name="Pluto", owner=mickey)
self.assertIsNone(pluto.full_clean())
def test_o2o_separation(self):
"OneToOne fields are constrained to a single database"
# Create a user and profile on the default database
alice = User.objects.db_manager('default').create_user('alice', 'alice@example.com')
alice_profile = UserProfile.objects.using('default').create(user=alice, flavor='chocolate')
# Create a user and profile on the other database
bob = User.objects.db_manager('other').create_user('bob', 'bob@example.com')
bob_profile = UserProfile.objects.using('other').create(user=bob, flavor='crunchy frog')
# Retrieve related objects; queries should be database constrained
alice = User.objects.using('default').get(username="alice")
self.assertEqual(alice.userprofile.flavor, "chocolate")
bob = User.objects.using('other').get(username="bob")
self.assertEqual(bob.userprofile.flavor, "crunchy frog")
# Check that queries work across joins
self.assertEqual(list(User.objects.using('default').filter(userprofile__flavor='chocolate').values_list('username', flat=True)),
['alice'])
self.assertEqual(list(User.objects.using('other').filter(userprofile__flavor='chocolate').values_list('username', flat=True)),
[])
self.assertEqual(list(User.objects.using('default').filter(userprofile__flavor='crunchy frog').values_list('username', flat=True)),
[])
self.assertEqual(list(User.objects.using('other').filter(userprofile__flavor='crunchy frog').values_list('username', flat=True)),
['bob'])
# Reget the objects to clear caches
alice_profile = UserProfile.objects.using('default').get(flavor='chocolate')
bob_profile = UserProfile.objects.using('other').get(flavor='crunchy frog')
# Retrieve related object by descriptor. Related objects should be database-bound
self.assertEqual(alice_profile.user.username, 'alice')
self.assertEqual(bob_profile.user.username, 'bob')
def test_o2o_cross_database_protection(self):
"Operations that involve sharing FK objects across databases raise an error"
# Create a user and profile on the default database
alice = User.objects.db_manager('default').create_user('alice', 'alice@example.com')
# Create a user and profile on the other database
bob = User.objects.db_manager('other').create_user('bob', 'bob@example.com')
# Set a one-to-one relation with an object from a different database
alice_profile = UserProfile.objects.using('default').create(user=alice, flavor='chocolate')
with self.assertRaises(ValueError):
bob.userprofile = alice_profile
# BUT! if you assign a FK object when the base object hasn't
# been saved yet, you implicitly assign the database for the
# base object.
bob_profile = UserProfile.objects.using('other').create(user=bob, flavor='crunchy frog')
new_bob_profile = UserProfile(flavor="spring surprise")
# assigning a profile requires an explicit pk as the object isn't saved
charlie = User(pk=51, username='charlie', email='charlie@example.com')
charlie.set_unusable_password()
# initially, no db assigned
self.assertEqual(new_bob_profile._state.db, None)
self.assertEqual(charlie._state.db, None)
# old object comes from 'other', so the new object is set to use 'other'...
new_bob_profile.user = bob
charlie.userprofile = bob_profile
self.assertEqual(new_bob_profile._state.db, 'other')
self.assertEqual(charlie._state.db, 'other')
# ... but it isn't saved yet
self.assertEqual(list(User.objects.using('other').values_list('username', flat=True)),
['bob'])
self.assertEqual(list(UserProfile.objects.using('other').values_list('flavor', flat=True)),
['crunchy frog'])
# When saved (no using required), new objects goes to 'other'
charlie.save()
bob_profile.save()
new_bob_profile.save()
self.assertEqual(list(User.objects.using('default').values_list('username', flat=True)),
['alice'])
self.assertEqual(list(User.objects.using('other').values_list('username', flat=True)),
['bob', 'charlie'])
self.assertEqual(list(UserProfile.objects.using('default').values_list('flavor', flat=True)),
['chocolate'])
self.assertEqual(list(UserProfile.objects.using('other').values_list('flavor', flat=True)),
['crunchy frog', 'spring surprise'])
# This also works if you assign the O2O relation in the constructor
denise = User.objects.db_manager('other').create_user('denise', 'denise@example.com')
denise_profile = UserProfile(flavor="tofu", user=denise)
self.assertEqual(denise_profile._state.db, 'other')
# ... but it isn't saved yet
self.assertEqual(list(UserProfile.objects.using('default').values_list('flavor', flat=True)),
['chocolate'])
self.assertEqual(list(UserProfile.objects.using('other').values_list('flavor', flat=True)),
['crunchy frog', 'spring surprise'])
# When saved, the new profile goes to 'other'
denise_profile.save()
self.assertEqual(list(UserProfile.objects.using('default').values_list('flavor', flat=True)),
['chocolate'])
self.assertEqual(list(UserProfile.objects.using('other').values_list('flavor', flat=True)),
['crunchy frog', 'spring surprise', 'tofu'])
def test_generic_key_separation(self):
"Generic fields are constrained to a single database"
# Create a book and author on the default database
pro = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
review1 = Review.objects.create(source="Python Monthly", content_object=pro)
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
review2 = Review.objects.using('other').create(source="Python Weekly", content_object=dive)
review1 = Review.objects.using('default').get(source="Python Monthly")
self.assertEqual(review1.content_object.title, "Pro Django")
review2 = Review.objects.using('other').get(source="Python Weekly")
self.assertEqual(review2.content_object.title, "Dive into Python")
# Reget the objects to clear caches
dive = Book.objects.using('other').get(title="Dive into Python")
# Retrieve related object by descriptor. Related objects should be database-bound
self.assertEqual(list(dive.reviews.all().values_list('source', flat=True)),
['Python Weekly'])
def test_generic_key_reverse_operations(self):
"Generic reverse manipulations are all constrained to a single DB"
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
temp = Book.objects.using('other').create(title="Temp",
published=datetime.date(2009, 5, 4))
review1 = Review.objects.using('other').create(source="Python Weekly", content_object=dive)
review2 = Review.objects.using('other').create(source="Python Monthly", content_object=temp)
self.assertEqual(list(Review.objects.using('default').filter(object_id=dive.pk).values_list('source', flat=True)),
[])
self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source', flat=True)),
['Python Weekly'])
# Add a second review
dive.reviews.add(review2)
self.assertEqual(list(Review.objects.using('default').filter(object_id=dive.pk).values_list('source', flat=True)),
[])
self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source', flat=True)),
['Python Monthly', 'Python Weekly'])
# Remove the second author
dive.reviews.remove(review1)
self.assertEqual(list(Review.objects.using('default').filter(object_id=dive.pk).values_list('source', flat=True)),
[])
self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source', flat=True)),
['Python Monthly'])
# Clear all reviews
dive.reviews.clear()
self.assertEqual(list(Review.objects.using('default').filter(object_id=dive.pk).values_list('source', flat=True)),
[])
self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source', flat=True)),
[])
# Create an author through the generic interface
dive.reviews.create(source='Python Daily')
self.assertEqual(list(Review.objects.using('default').filter(object_id=dive.pk).values_list('source', flat=True)),
[])
self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source', flat=True)),
['Python Daily'])
def test_generic_key_cross_database_protection(self):
"Operations that involve sharing generic key objects across databases raise an error"
# Create a book and author on the default database
pro = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
review1 = Review.objects.create(source="Python Monthly", content_object=pro)
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
Review.objects.using('other').create(source="Python Weekly", content_object=dive)
# Set a foreign key with an object from a different database
with self.assertRaises(ValueError):
review1.content_object = dive
# Add to a foreign key set with an object from a different database
with self.assertRaises(ValueError):
with transaction.atomic(using='other'):
dive.reviews.add(review1)
# BUT! if you assign a FK object when the base object hasn't
# been saved yet, you implicitly assign the database for the
# base object.
review3 = Review(source="Python Daily")
# initially, no db assigned
self.assertEqual(review3._state.db, None)
# Dive comes from 'other', so review3 is set to use 'other'...
review3.content_object = dive
self.assertEqual(review3._state.db, 'other')
# ... but it isn't saved yet
self.assertEqual(list(Review.objects.using('default').filter(object_id=pro.pk).values_list('source', flat=True)),
['Python Monthly'])
self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source', flat=True)),
['Python Weekly'])
# When saved, John goes to 'other'
review3.save()
self.assertEqual(list(Review.objects.using('default').filter(object_id=pro.pk).values_list('source', flat=True)),
['Python Monthly'])
self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source', flat=True)),
['Python Daily', 'Python Weekly'])
def test_generic_key_deletion(self):
"Cascaded deletions of Generic Key relations issue queries on the right database"
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
Review.objects.using('other').create(source="Python Weekly", content_object=dive)
# Check the initial state
self.assertEqual(Book.objects.using('default').count(), 0)
self.assertEqual(Review.objects.using('default').count(), 0)
self.assertEqual(Book.objects.using('other').count(), 1)
self.assertEqual(Review.objects.using('other').count(), 1)
# Delete the Book object, which will cascade onto the pet
dive.delete(using='other')
self.assertEqual(Book.objects.using('default').count(), 0)
self.assertEqual(Review.objects.using('default').count(), 0)
# Both the pet and the person have been deleted from the right database
self.assertEqual(Book.objects.using('other').count(), 0)
self.assertEqual(Review.objects.using('other').count(), 0)
def test_ordering(self):
"get_next_by_XXX commands stick to a single database"
Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
learn = Book.objects.using('other').create(title="Learning Python",
published=datetime.date(2008, 7, 16))
self.assertEqual(learn.get_next_by_published().title, "Dive into Python")
self.assertEqual(dive.get_previous_by_published().title, "Learning Python")
def test_raw(self):
"test the raw() method across databases"
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
val = Book.objects.db_manager("other").raw('SELECT id FROM multiple_database_book')
self.assertQuerysetEqual(val, [dive.pk], attrgetter("pk"))
val = Book.objects.raw('SELECT id FROM multiple_database_book').using('other')
self.assertQuerysetEqual(val, [dive.pk], attrgetter("pk"))
def test_select_related(self):
"Database assignment is retained if an object is retrieved with select_related()"
# Create a book and author on the other database
mark = Person.objects.using('other').create(name="Mark Pilgrim")
Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4),
editor=mark)
# Retrieve the Person using select_related()
book = Book.objects.using('other').select_related('editor').get(title="Dive into Python")
# The editor instance should have a db state
self.assertEqual(book.editor._state.db, 'other')
def test_subquery(self):
"""Make sure as_sql works with subqueries and primary/replica."""
sub = Person.objects.using('other').filter(name='fff')
qs = Book.objects.filter(editor__in=sub)
# When you call __str__ on the query object, it doesn't know about using
# so it falls back to the default. If the subquery explicitly uses a
# different database, an error should be raised.
self.assertRaises(ValueError, str, qs.query)
# Evaluating the query shouldn't work, either
with self.assertRaises(ValueError):
for obj in qs:
pass
def test_related_manager(self):
"Related managers return managers, not querysets"
mark = Person.objects.using('other').create(name="Mark Pilgrim")
# extra_arg is removed by the BookManager's implementation of
# create(); but the BookManager's implementation won't get called
# unless edited returns a Manager, not a queryset
mark.book_set.create(title="Dive into Python",
published=datetime.date(2009, 5, 4),
extra_arg=True)
mark.book_set.get_or_create(title="Dive into Python",
published=datetime.date(2009, 5, 4),
extra_arg=True)
mark.edited.create(title="Dive into Water",
published=datetime.date(2009, 5, 4),
extra_arg=True)
mark.edited.get_or_create(title="Dive into Water",
published=datetime.date(2009, 5, 4),
extra_arg=True)
class ConnectionRouterTestCase(TestCase):
@override_settings(DATABASE_ROUTERS=[
'multiple_database.tests.TestRouter',
'multiple_database.tests.WriteRouter'])
def test_router_init_default(self):
connection_router = ConnectionRouter()
self.assertListEqual([r.__class__.__name__ for r in connection_router.routers],
['TestRouter', 'WriteRouter'])
def test_router_init_arg(self):
connection_router = ConnectionRouter([
'multiple_database.tests.TestRouter',
'multiple_database.tests.WriteRouter'
])
self.assertListEqual([r.__class__.__name__ for r in connection_router.routers],
['TestRouter', 'WriteRouter'])
# Init with instances instead of strings
connection_router = ConnectionRouter([TestRouter(), WriteRouter()])
self.assertListEqual([r.__class__.__name__ for r in connection_router.routers],
['TestRouter', 'WriteRouter'])
# Make the 'other' database appear to be a replica of the 'default'
@override_settings(DATABASE_ROUTERS=[TestRouter()])
class RouterTestCase(TestCase):
multi_db = True
def test_db_selection(self):
"Check that querysets obey the router for db suggestions"
self.assertEqual(Book.objects.db, 'other')
self.assertEqual(Book.objects.all().db, 'other')
self.assertEqual(Book.objects.using('default').db, 'default')
self.assertEqual(Book.objects.db_manager('default').db, 'default')
self.assertEqual(Book.objects.db_manager('default').all().db, 'default')
def test_migrate_selection(self):
"Synchronization behavior is predictable"
self.assertTrue(router.allow_migrate_model('default', User))
self.assertTrue(router.allow_migrate_model('default', Book))
self.assertTrue(router.allow_migrate_model('other', User))
self.assertTrue(router.allow_migrate_model('other', Book))
with override_settings(DATABASE_ROUTERS=[TestRouter(), AuthRouter()]):
# Add the auth router to the chain. TestRouter is a universal
# synchronizer, so it should have no effect.
self.assertTrue(router.allow_migrate_model('default', User))
self.assertTrue(router.allow_migrate_model('default', Book))
self.assertTrue(router.allow_migrate_model('other', User))
self.assertTrue(router.allow_migrate_model('other', Book))
with override_settings(DATABASE_ROUTERS=[AuthRouter(), TestRouter()]):
# Now check what happens if the router order is reversed.
self.assertFalse(router.allow_migrate_model('default', User))
self.assertTrue(router.allow_migrate_model('default', Book))
self.assertTrue(router.allow_migrate_model('other', User))
self.assertTrue(router.allow_migrate_model('other', Book))
def test_migrate_legacy_router(self):
class LegacyRouter(object):
def allow_migrate(self, db, model):
"""
Deprecated allow_migrate signature should trigger
RemovedInDjango110Warning.
"""
assert db == 'default'
assert model is User
return True
with override_settings(DATABASE_ROUTERS=[LegacyRouter()]):
with warnings.catch_warnings(record=True) as recorded:
warnings.filterwarnings('always')
msg = (
"The signature of allow_migrate has changed from "
"allow_migrate(self, db, model) to "
"allow_migrate(self, db, app_label, model_name=None, **hints). "
"Support for the old signature will be removed in Django 1.10."
)
self.assertTrue(router.allow_migrate_model('default', User))
self.assertEqual(force_text(recorded.pop().message), msg)
self.assertEqual(recorded, [])
self.assertTrue(router.allow_migrate('default', 'app_label'))
self.assertEqual(force_text(recorded.pop().message), msg)
def test_allow_syncdb_deprecation(self):
class LegacyRouter(object):
def allow_syncdb(self, db, model):
assert db == 'default'
assert model is User
return True
with override_settings(DATABASE_ROUTERS=[LegacyRouter()]):
with warnings.catch_warnings(record=True) as recorded:
warnings.filterwarnings('always')
msg = (
"Router.allow_syncdb has been deprecated and will stop "
"working in Django 1.9. Rename the method to allow_migrate."
)
self.assertTrue(router.allow_migrate_model('default', User))
self.assertEqual(force_text(recorded.pop().message), msg)
self.assertEqual(recorded, [])
self.assertTrue(router.allow_migrate('default', 'app_label'))
self.assertEqual(force_text(recorded.pop().message), msg)
def test_partial_router(self):
"A router can choose to implement a subset of methods"
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
# First check the baseline behavior.
self.assertEqual(router.db_for_read(User), 'other')
self.assertEqual(router.db_for_read(Book), 'other')
self.assertEqual(router.db_for_write(User), 'default')
self.assertEqual(router.db_for_write(Book), 'default')
self.assertTrue(router.allow_relation(dive, dive))
self.assertTrue(router.allow_migrate_model('default', User))
self.assertTrue(router.allow_migrate_model('default', Book))
with override_settings(DATABASE_ROUTERS=[WriteRouter(), AuthRouter(), TestRouter()]):
self.assertEqual(router.db_for_read(User), 'default')
self.assertEqual(router.db_for_read(Book), 'other')
self.assertEqual(router.db_for_write(User), 'writer')
self.assertEqual(router.db_for_write(Book), 'writer')
self.assertTrue(router.allow_relation(dive, dive))
self.assertFalse(router.allow_migrate_model('default', User))
self.assertTrue(router.allow_migrate_model('default', Book))
def test_database_routing(self):
marty = Person.objects.using('default').create(name="Marty Alchin")
pro = Book.objects.using('default').create(title="Pro Django",
published=datetime.date(2008, 12, 16),
editor=marty)
pro.authors = [marty]
# Create a book and author on the other database
Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
# An update query will be routed to the default database
Book.objects.filter(title='Pro Django').update(pages=200)
with self.assertRaises(Book.DoesNotExist):
# By default, the get query will be directed to 'other'
Book.objects.get(title='Pro Django')
# But the same query issued explicitly at a database will work.
pro = Book.objects.using('default').get(title='Pro Django')
# Check that the update worked.
self.assertEqual(pro.pages, 200)
# An update query with an explicit using clause will be routed
# to the requested database.
Book.objects.using('other').filter(title='Dive into Python').update(pages=300)
self.assertEqual(Book.objects.get(title='Dive into Python').pages, 300)
# Related object queries stick to the same database
# as the original object, regardless of the router
self.assertEqual(list(pro.authors.values_list('name', flat=True)), ['Marty Alchin'])
self.assertEqual(pro.editor.name, 'Marty Alchin')
# get_or_create is a special case. The get needs to be targeted at
# the write database in order to avoid potential transaction
# consistency problems
book, created = Book.objects.get_or_create(title="Pro Django")
self.assertFalse(created)
book, created = Book.objects.get_or_create(title="Dive Into Python",
defaults={'published': datetime.date(2009, 5, 4)})
self.assertTrue(created)
# Check the head count of objects
self.assertEqual(Book.objects.using('default').count(), 2)
self.assertEqual(Book.objects.using('other').count(), 1)
# If a database isn't specified, the read database is used
self.assertEqual(Book.objects.count(), 1)
# A delete query will also be routed to the default database
Book.objects.filter(pages__gt=150).delete()
# The default database has lost the book.
self.assertEqual(Book.objects.using('default').count(), 1)
self.assertEqual(Book.objects.using('other').count(), 1)
def test_foreign_key_cross_database_protection(self):
"Foreign keys can cross databases if they two databases have a common source"
# Create a book and author on the default database
pro = Book.objects.using('default').create(title="Pro Django",
published=datetime.date(2008, 12, 16))
marty = Person.objects.using('default').create(name="Marty Alchin")
# Create a book and author on the other database
dive = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4))
mark = Person.objects.using('other').create(name="Mark Pilgrim")
# Set a foreign key with an object from a different database
try:
dive.editor = marty
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Database assignments of original objects haven't changed...
self.assertEqual(marty._state.db, 'default')
self.assertEqual(pro._state.db, 'default')
self.assertEqual(dive._state.db, 'other')
self.assertEqual(mark._state.db, 'other')
# ... but they will when the affected object is saved.
dive.save()
self.assertEqual(dive._state.db, 'default')
# ...and the source database now has a copy of any object saved
try:
Book.objects.using('default').get(title='Dive into Python').delete()
except Book.DoesNotExist:
self.fail('Source database should have a copy of saved object')
# This isn't a real primary/replica database, so restore the original from other
dive = Book.objects.using('other').get(title='Dive into Python')
self.assertEqual(dive._state.db, 'other')
# Set a foreign key set with an object from a different database
try:
marty.edited = [pro, dive]
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Assignment implies a save, so database assignments of original objects have changed...
self.assertEqual(marty._state.db, 'default')
self.assertEqual(pro._state.db, 'default')
self.assertEqual(dive._state.db, 'default')
self.assertEqual(mark._state.db, 'other')
# ...and the source database now has a copy of any object saved
try:
Book.objects.using('default').get(title='Dive into Python').delete()
except Book.DoesNotExist:
self.fail('Source database should have a copy of saved object')
# This isn't a real primary/replica database, so restore the original from other
dive = Book.objects.using('other').get(title='Dive into Python')
self.assertEqual(dive._state.db, 'other')
# Add to a foreign key set with an object from a different database
try:
marty.edited.add(dive)
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Add implies a save, so database assignments of original objects have changed...
self.assertEqual(marty._state.db, 'default')
self.assertEqual(pro._state.db, 'default')
self.assertEqual(dive._state.db, 'default')
self.assertEqual(mark._state.db, 'other')
# ...and the source database now has a copy of any object saved
try:
Book.objects.using('default').get(title='Dive into Python').delete()
except Book.DoesNotExist:
self.fail('Source database should have a copy of saved object')
# This isn't a real primary/replica database, so restore the original from other
dive = Book.objects.using('other').get(title='Dive into Python')
# If you assign a FK object when the base object hasn't
# been saved yet, you implicitly assign the database for the
# base object.
chris = Person(name="Chris Mills")
html5 = Book(title="Dive into HTML5", published=datetime.date(2010, 3, 15))
# initially, no db assigned
self.assertEqual(chris._state.db, None)
self.assertEqual(html5._state.db, None)
# old object comes from 'other', so the new object is set to use the
# source of 'other'...
self.assertEqual(dive._state.db, 'other')
chris.save()
dive.editor = chris
html5.editor = mark
self.assertEqual(dive._state.db, 'other')
self.assertEqual(mark._state.db, 'other')
self.assertEqual(chris._state.db, 'default')
self.assertEqual(html5._state.db, 'default')
# This also works if you assign the FK in the constructor
water = Book(title="Dive into Water", published=datetime.date(2001, 1, 1), editor=mark)
self.assertEqual(water._state.db, 'default')
# For the remainder of this test, create a copy of 'mark' in the
# 'default' database to prevent integrity errors on backends that
# don't defer constraints checks until the end of the transaction
mark.save(using='default')
# This moved 'mark' in the 'default' database, move it back in 'other'
mark.save(using='other')
self.assertEqual(mark._state.db, 'other')
# If you create an object through a FK relation, it will be
# written to the write database, even if the original object
# was on the read database
cheesecake = mark.edited.create(title='Dive into Cheesecake', published=datetime.date(2010, 3, 15))
self.assertEqual(cheesecake._state.db, 'default')
# Same goes for get_or_create, regardless of whether getting or creating
cheesecake, created = mark.edited.get_or_create(title='Dive into Cheesecake', published=datetime.date(2010, 3, 15))
self.assertEqual(cheesecake._state.db, 'default')
puddles, created = mark.edited.get_or_create(title='Dive into Puddles', published=datetime.date(2010, 3, 15))
self.assertEqual(puddles._state.db, 'default')
def test_m2m_cross_database_protection(self):
"M2M relations can cross databases if the database share a source"
# Create books and authors on the inverse to the usual database
pro = Book.objects.using('other').create(pk=1, title="Pro Django",
published=datetime.date(2008, 12, 16))
marty = Person.objects.using('other').create(pk=1, name="Marty Alchin")
dive = Book.objects.using('default').create(pk=2, title="Dive into Python",
published=datetime.date(2009, 5, 4))
mark = Person.objects.using('default').create(pk=2, name="Mark Pilgrim")
# Now save back onto the usual database.
# This simulates primary/replica - the objects exist on both database,
# but the _state.db is as it is for all other tests.
pro.save(using='default')
marty.save(using='default')
dive.save(using='other')
mark.save(using='other')
# Check that we have 2 of both types of object on both databases
self.assertEqual(Book.objects.using('default').count(), 2)
self.assertEqual(Book.objects.using('other').count(), 2)
self.assertEqual(Person.objects.using('default').count(), 2)
self.assertEqual(Person.objects.using('other').count(), 2)
# Set a m2m set with an object from a different database
try:
marty.book_set = [pro, dive]
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Database assignments don't change
self.assertEqual(marty._state.db, 'default')
self.assertEqual(pro._state.db, 'default')
self.assertEqual(dive._state.db, 'other')
self.assertEqual(mark._state.db, 'other')
# All m2m relations should be saved on the default database
self.assertEqual(Book.authors.through.objects.using('default').count(), 2)
self.assertEqual(Book.authors.through.objects.using('other').count(), 0)
# Reset relations
Book.authors.through.objects.using('default').delete()
# Add to an m2m with an object from a different database
try:
marty.book_set.add(dive)
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Database assignments don't change
self.assertEqual(marty._state.db, 'default')
self.assertEqual(pro._state.db, 'default')
self.assertEqual(dive._state.db, 'other')
self.assertEqual(mark._state.db, 'other')
# All m2m relations should be saved on the default database
self.assertEqual(Book.authors.through.objects.using('default').count(), 1)
self.assertEqual(Book.authors.through.objects.using('other').count(), 0)
# Reset relations
Book.authors.through.objects.using('default').delete()
# Set a reverse m2m with an object from a different database
try:
dive.authors = [mark, marty]
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Database assignments don't change
self.assertEqual(marty._state.db, 'default')
self.assertEqual(pro._state.db, 'default')
self.assertEqual(dive._state.db, 'other')
self.assertEqual(mark._state.db, 'other')
# All m2m relations should be saved on the default database
self.assertEqual(Book.authors.through.objects.using('default').count(), 2)
self.assertEqual(Book.authors.through.objects.using('other').count(), 0)
# Reset relations
Book.authors.through.objects.using('default').delete()
self.assertEqual(Book.authors.through.objects.using('default').count(), 0)
self.assertEqual(Book.authors.through.objects.using('other').count(), 0)
# Add to a reverse m2m with an object from a different database
try:
dive.authors.add(marty)
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Database assignments don't change
self.assertEqual(marty._state.db, 'default')
self.assertEqual(pro._state.db, 'default')
self.assertEqual(dive._state.db, 'other')
self.assertEqual(mark._state.db, 'other')
# All m2m relations should be saved on the default database
self.assertEqual(Book.authors.through.objects.using('default').count(), 1)
self.assertEqual(Book.authors.through.objects.using('other').count(), 0)
# If you create an object through a M2M relation, it will be
# written to the write database, even if the original object
# was on the read database
alice = dive.authors.create(name='Alice')
self.assertEqual(alice._state.db, 'default')
# Same goes for get_or_create, regardless of whether getting or creating
alice, created = dive.authors.get_or_create(name='Alice')
self.assertEqual(alice._state.db, 'default')
bob, created = dive.authors.get_or_create(name='Bob')
self.assertEqual(bob._state.db, 'default')
def test_o2o_cross_database_protection(self):
"Operations that involve sharing FK objects across databases raise an error"
# Create a user and profile on the default database
alice = User.objects.db_manager('default').create_user('alice', 'alice@example.com')
# Create a user and profile on the other database
bob = User.objects.db_manager('other').create_user('bob', 'bob@example.com')
# Set a one-to-one relation with an object from a different database
alice_profile = UserProfile.objects.create(user=alice, flavor='chocolate')
try:
bob.userprofile = alice_profile
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Database assignments of original objects haven't changed...
self.assertEqual(alice._state.db, 'default')
self.assertEqual(alice_profile._state.db, 'default')
self.assertEqual(bob._state.db, 'other')
# ... but they will when the affected object is saved.
bob.save()
self.assertEqual(bob._state.db, 'default')
def test_generic_key_cross_database_protection(self):
"Generic Key operations can span databases if they share a source"
# Create a book and author on the default database
pro = Book.objects.using(
'default').create(title="Pro Django", published=datetime.date(2008, 12, 16))
review1 = Review.objects.using(
'default').create(source="Python Monthly", content_object=pro)
# Create a book and author on the other database
dive = Book.objects.using(
'other').create(title="Dive into Python", published=datetime.date(2009, 5, 4))
review2 = Review.objects.using(
'other').create(source="Python Weekly", content_object=dive)
# Set a generic foreign key with an object from a different database
try:
review1.content_object = dive
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Database assignments of original objects haven't changed...
self.assertEqual(pro._state.db, 'default')
self.assertEqual(review1._state.db, 'default')
self.assertEqual(dive._state.db, 'other')
self.assertEqual(review2._state.db, 'other')
# ... but they will when the affected object is saved.
dive.save()
self.assertEqual(review1._state.db, 'default')
self.assertEqual(dive._state.db, 'default')
# ...and the source database now has a copy of any object saved
try:
Book.objects.using('default').get(title='Dive into Python').delete()
except Book.DoesNotExist:
self.fail('Source database should have a copy of saved object')
# This isn't a real primary/replica database, so restore the original from other
dive = Book.objects.using('other').get(title='Dive into Python')
self.assertEqual(dive._state.db, 'other')
# Add to a generic foreign key set with an object from a different database
try:
dive.reviews.add(review1)
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
# Database assignments of original objects haven't changed...
self.assertEqual(pro._state.db, 'default')
self.assertEqual(review1._state.db, 'default')
self.assertEqual(dive._state.db, 'other')
self.assertEqual(review2._state.db, 'other')
# ... but they will when the affected object is saved.
dive.save()
self.assertEqual(dive._state.db, 'default')
# ...and the source database now has a copy of any object saved
try:
Book.objects.using('default').get(title='Dive into Python').delete()
except Book.DoesNotExist:
self.fail('Source database should have a copy of saved object')
# BUT! if you assign a FK object when the base object hasn't
# been saved yet, you implicitly assign the database for the
# base object.
review3 = Review(source="Python Daily")
# initially, no db assigned
self.assertEqual(review3._state.db, None)
# Dive comes from 'other', so review3 is set to use the source of 'other'...
review3.content_object = dive
self.assertEqual(review3._state.db, 'default')
# If you create an object through a M2M relation, it will be
# written to the write database, even if the original object
# was on the read database
dive = Book.objects.using('other').get(title='Dive into Python')
nyt = dive.reviews.create(source="New York Times", content_object=dive)
self.assertEqual(nyt._state.db, 'default')
def test_m2m_managers(self):
"M2M relations are represented by managers, and can be controlled like managers"
pro = Book.objects.using('other').create(pk=1, title="Pro Django",
published=datetime.date(2008, 12, 16))
marty = Person.objects.using('other').create(pk=1, name="Marty Alchin")
self.assertEqual(pro.authors.db, 'other')
self.assertEqual(pro.authors.db_manager('default').db, 'default')
self.assertEqual(pro.authors.db_manager('default').all().db, 'default')
self.assertEqual(marty.book_set.db, 'other')
self.assertEqual(marty.book_set.db_manager('default').db, 'default')
self.assertEqual(marty.book_set.db_manager('default').all().db, 'default')
def test_foreign_key_managers(self):
"FK reverse relations are represented by managers, and can be controlled like managers"
marty = Person.objects.using('other').create(pk=1, name="Marty Alchin")
Book.objects.using('other').create(pk=1, title="Pro Django",
published=datetime.date(2008, 12, 16),
editor=marty)
self.assertEqual(marty.edited.db, 'other')
self.assertEqual(marty.edited.db_manager('default').db, 'default')
self.assertEqual(marty.edited.db_manager('default').all().db, 'default')
def test_generic_key_managers(self):
"Generic key relations are represented by managers, and can be controlled like managers"
pro = Book.objects.using('other').create(title="Pro Django",
published=datetime.date(2008, 12, 16))
Review.objects.using('other').create(source="Python Monthly",
content_object=pro)
self.assertEqual(pro.reviews.db, 'other')
self.assertEqual(pro.reviews.db_manager('default').db, 'default')
self.assertEqual(pro.reviews.db_manager('default').all().db, 'default')
def test_subquery(self):
"""Make sure as_sql works with subqueries and primary/replica."""
# Create a book and author on the other database
mark = Person.objects.using('other').create(name="Mark Pilgrim")
Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4),
editor=mark)
sub = Person.objects.filter(name='Mark Pilgrim')
qs = Book.objects.filter(editor__in=sub)
# When you call __str__ on the query object, it doesn't know about using
# so it falls back to the default. Don't let routing instructions
# force the subquery to an incompatible database.
str(qs.query)
# If you evaluate the query, it should work, running on 'other'
self.assertEqual(list(qs.values_list('title', flat=True)), ['Dive into Python'])
def test_deferred_models(self):
mark_def = Person.objects.using('default').create(name="Mark Pilgrim")
mark_other = Person.objects.using('other').create(name="Mark Pilgrim")
orig_b = Book.objects.using('other').create(title="Dive into Python",
published=datetime.date(2009, 5, 4),
editor=mark_other)
b = Book.objects.using('other').only('title').get(pk=orig_b.pk)
self.assertEqual(b.published, datetime.date(2009, 5, 4))
b = Book.objects.using('other').only('title').get(pk=orig_b.pk)
b.editor = mark_def
b.save(using='default')
self.assertEqual(Book.objects.using('default').get(pk=b.pk).published,
datetime.date(2009, 5, 4))
@override_settings(DATABASE_ROUTERS=[AuthRouter()])
class AuthTestCase(TestCase):
multi_db = True
def test_auth_manager(self):
"The methods on the auth manager obey database hints"
# Create one user using default allocation policy
User.objects.create_user('alice', 'alice@example.com')
# Create another user, explicitly specifying the database
User.objects.db_manager('default').create_user('bob', 'bob@example.com')
# The second user only exists on the other database
alice = User.objects.using('other').get(username='alice')
self.assertEqual(alice.username, 'alice')
self.assertEqual(alice._state.db, 'other')
self.assertRaises(User.DoesNotExist, User.objects.using('default').get, username='alice')
# The second user only exists on the default database
bob = User.objects.using('default').get(username='bob')
self.assertEqual(bob.username, 'bob')
self.assertEqual(bob._state.db, 'default')
self.assertRaises(User.DoesNotExist, User.objects.using('other').get, username='bob')
# That is... there is one user on each database
self.assertEqual(User.objects.using('default').count(), 1)
self.assertEqual(User.objects.using('other').count(), 1)
def test_dumpdata(self):
"Check that dumpdata honors allow_migrate restrictions on the router"
User.objects.create_user('alice', 'alice@example.com')
User.objects.db_manager('default').create_user('bob', 'bob@example.com')
# Check that dumping the default database doesn't try to include auth
# because allow_migrate prohibits auth on default
new_io = StringIO()
management.call_command('dumpdata', 'auth', format='json', database='default', stdout=new_io)
command_output = new_io.getvalue().strip()
self.assertEqual(command_output, '[]')
# Check that dumping the other database does include auth
new_io = StringIO()
management.call_command('dumpdata', 'auth', format='json', database='other', stdout=new_io)
command_output = new_io.getvalue().strip()
self.assertIn('"email": "alice@example.com"', command_output)
class AntiPetRouter(object):
# A router that only expresses an opinion on migrate,
# passing pets to the 'other' database
def allow_migrate(self, db, app_label, model_name=None, **hints):
if db == 'other':
return model_name == 'pet'
else:
return model_name != 'pet'
class FixtureTestCase(TestCase):
multi_db = True
fixtures = ['multidb-common', 'multidb']
@override_settings(DATABASE_ROUTERS=[AntiPetRouter()])
def test_fixture_loading(self):
"Multi-db fixtures are loaded correctly"
# Check that "Pro Django" exists on the default database, but not on other database
try:
Book.objects.get(title="Pro Django")
Book.objects.using('default').get(title="Pro Django")
except Book.DoesNotExist:
self.fail('"Pro Django" should exist on default database')
self.assertRaises(
Book.DoesNotExist,
Book.objects.using('other').get,
title="Pro Django"
)
# Check that "Dive into Python" exists on the default database, but not on other database
try:
Book.objects.using('other').get(title="Dive into Python")
except Book.DoesNotExist:
self.fail('"Dive into Python" should exist on other database')
self.assertRaises(
Book.DoesNotExist,
Book.objects.get,
title="Dive into Python"
)
self.assertRaises(
Book.DoesNotExist,
Book.objects.using('default').get,
title="Dive into Python"
)
# Check that "Definitive Guide" exists on the both databases
try:
Book.objects.get(title="The Definitive Guide to Django")
Book.objects.using('default').get(title="The Definitive Guide to Django")
Book.objects.using('other').get(title="The Definitive Guide to Django")
except Book.DoesNotExist:
self.fail('"The Definitive Guide to Django" should exist on both databases')
@override_settings(DATABASE_ROUTERS=[AntiPetRouter()])
def test_pseudo_empty_fixtures(self):
"A fixture can contain entries, but lead to nothing in the database; this shouldn't raise an error (ref #14068)"
new_io = StringIO()
management.call_command('loaddata', 'pets', stdout=new_io, stderr=new_io)
command_output = new_io.getvalue().strip()
# No objects will actually be loaded
self.assertEqual(command_output, "Installed 0 object(s) (of 2) from 1 fixture(s)")
class PickleQuerySetTestCase(TestCase):
multi_db = True
def test_pickling(self):
for db in connections:
Book.objects.using(db).create(title='Dive into Python', published=datetime.date(2009, 5, 4))
qs = Book.objects.all()
self.assertEqual(qs.db, pickle.loads(pickle.dumps(qs)).db)
class DatabaseReceiver(object):
"""
Used in the tests for the database argument in signals (#13552)
"""
def __call__(self, signal, sender, **kwargs):
self._database = kwargs['using']
class WriteToOtherRouter(object):
"""
A router that sends all writes to the other database.
"""
def db_for_write(self, model, **hints):
return "other"
class SignalTests(TestCase):
multi_db = True
def override_router(self):
return override_settings(DATABASE_ROUTERS=[WriteToOtherRouter()])
def test_database_arg_save_and_delete(self):
"""
Tests that the pre/post_save signal contains the correct database.
(#13552)
"""
# Make some signal receivers
pre_save_receiver = DatabaseReceiver()
post_save_receiver = DatabaseReceiver()
pre_delete_receiver = DatabaseReceiver()
post_delete_receiver = DatabaseReceiver()
# Make model and connect receivers
signals.pre_save.connect(sender=Person, receiver=pre_save_receiver)
signals.post_save.connect(sender=Person, receiver=post_save_receiver)
signals.pre_delete.connect(sender=Person, receiver=pre_delete_receiver)
signals.post_delete.connect(sender=Person, receiver=post_delete_receiver)
p = Person.objects.create(name='Darth Vader')
# Save and test receivers got calls
p.save()
self.assertEqual(pre_save_receiver._database, DEFAULT_DB_ALIAS)
self.assertEqual(post_save_receiver._database, DEFAULT_DB_ALIAS)
# Delete, and test
p.delete()
self.assertEqual(pre_delete_receiver._database, DEFAULT_DB_ALIAS)
self.assertEqual(post_delete_receiver._database, DEFAULT_DB_ALIAS)
# Save again to a different database
p.save(using="other")
self.assertEqual(pre_save_receiver._database, "other")
self.assertEqual(post_save_receiver._database, "other")
# Delete, and test
p.delete(using="other")
self.assertEqual(pre_delete_receiver._database, "other")
self.assertEqual(post_delete_receiver._database, "other")
signals.pre_save.disconnect(sender=Person, receiver=pre_save_receiver)
signals.post_save.disconnect(sender=Person, receiver=post_save_receiver)
signals.pre_delete.disconnect(sender=Person, receiver=pre_delete_receiver)
signals.post_delete.disconnect(sender=Person, receiver=post_delete_receiver)
def test_database_arg_m2m(self):
"""
Test that the m2m_changed signal has a correct database arg (#13552)
"""
# Make a receiver
receiver = DatabaseReceiver()
# Connect it
signals.m2m_changed.connect(receiver=receiver)
# Create the models that will be used for the tests
b = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
p = Person.objects.create(name="Marty Alchin")
# Create a copy of the models on the 'other' database to prevent
# integrity errors on backends that don't defer constraints checks
Book.objects.using('other').create(pk=b.pk, title=b.title,
published=b.published)
Person.objects.using('other').create(pk=p.pk, name=p.name)
# Test addition
b.authors.add(p)
self.assertEqual(receiver._database, DEFAULT_DB_ALIAS)
with self.override_router():
b.authors.add(p)
self.assertEqual(receiver._database, "other")
# Test removal
b.authors.remove(p)
self.assertEqual(receiver._database, DEFAULT_DB_ALIAS)
with self.override_router():
b.authors.remove(p)
self.assertEqual(receiver._database, "other")
# Test addition in reverse
p.book_set.add(b)
self.assertEqual(receiver._database, DEFAULT_DB_ALIAS)
with self.override_router():
p.book_set.add(b)
self.assertEqual(receiver._database, "other")
# Test clearing
b.authors.clear()
self.assertEqual(receiver._database, DEFAULT_DB_ALIAS)
with self.override_router():
b.authors.clear()
self.assertEqual(receiver._database, "other")
class AttributeErrorRouter(object):
"A router to test the exception handling of ConnectionRouter"
def db_for_read(self, model, **hints):
raise AttributeError
def db_for_write(self, model, **hints):
raise AttributeError
class RouterAttributeErrorTestCase(TestCase):
multi_db = True
def override_router(self):
return override_settings(DATABASE_ROUTERS=[AttributeErrorRouter()])
def test_attribute_error_read(self):
"Check that the AttributeError from AttributeErrorRouter bubbles up"
b = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
with self.override_router():
self.assertRaises(AttributeError, Book.objects.get, pk=b.pk)
def test_attribute_error_save(self):
"Check that the AttributeError from AttributeErrorRouter bubbles up"
dive = Book()
dive.title = "Dive into Python"
dive.published = datetime.date(2009, 5, 4)
with self.override_router():
self.assertRaises(AttributeError, dive.save)
def test_attribute_error_delete(self):
"Check that the AttributeError from AttributeErrorRouter bubbles up"
b = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
p = Person.objects.create(name="Marty Alchin")
b.authors = [p]
b.editor = p
with self.override_router():
self.assertRaises(AttributeError, b.delete)
def test_attribute_error_m2m(self):
"Check that the AttributeError from AttributeErrorRouter bubbles up"
b = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
p = Person.objects.create(name="Marty Alchin")
with self.override_router():
self.assertRaises(AttributeError, setattr, b, 'authors', [p])
class ModelMetaRouter(object):
"A router to ensure model arguments are real model classes"
def db_for_write(self, model, **hints):
if not hasattr(model, '_meta'):
raise ValueError
@override_settings(DATABASE_ROUTERS=[ModelMetaRouter()])
class RouterModelArgumentTestCase(TestCase):
multi_db = True
def test_m2m_collection(self):
b = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
p = Person.objects.create(name="Marty Alchin")
# test add
b.authors.add(p)
# test remove
b.authors.remove(p)
# test clear
b.authors.clear()
# test setattr
b.authors = [p]
# test M2M collection
b.delete()
def test_foreignkey_collection(self):
person = Person.objects.create(name='Bob')
Pet.objects.create(owner=person, name='Wart')
# test related FK collection
person.delete()
class SyncOnlyDefaultDatabaseRouter(object):
def allow_migrate(self, db, app_label, **hints):
return db == DEFAULT_DB_ALIAS
class MigrateTestCase(TestCase):
available_apps = [
'multiple_database',
'django.contrib.auth',
'django.contrib.contenttypes'
]
multi_db = True
def test_migrate_to_other_database(self):
"""Regression test for #16039: migrate with --database option."""
cts = ContentType.objects.using('other').filter(app_label='multiple_database')
count = cts.count()
self.assertGreater(count, 0)
cts.delete()
management.call_command('migrate', verbosity=0, interactive=False,
load_initial_data=False, database='other')
self.assertEqual(cts.count(), count)
def test_migrate_to_other_database_with_router(self):
"""Regression test for #16039: migrate with --database option."""
cts = ContentType.objects.using('other').filter(app_label='multiple_database')
cts.delete()
with override_settings(DATABASE_ROUTERS=[SyncOnlyDefaultDatabaseRouter()]):
management.call_command('migrate', verbosity=0, interactive=False,
load_initial_data=False, database='other')
self.assertEqual(cts.count(), 0)
class RouterUsed(Exception):
WRITE = 'write'
def __init__(self, mode, model, hints):
self.mode = mode
self.model = model
self.hints = hints
class RouteForWriteTestCase(TestCase):
multi_db = True
class WriteCheckRouter(object):
def db_for_write(self, model, **hints):
raise RouterUsed(mode=RouterUsed.WRITE, model=model, hints=hints)
def override_router(self):
return override_settings(DATABASE_ROUTERS=[RouteForWriteTestCase.WriteCheckRouter()])
def test_fk_delete(self):
owner = Person.objects.create(name='Someone')
pet = Pet.objects.create(name='fido', owner=owner)
try:
with self.override_router():
pet.owner.delete()
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Person)
self.assertEqual(e.hints, {'instance': owner})
def test_reverse_fk_delete(self):
owner = Person.objects.create(name='Someone')
to_del_qs = owner.pet_set.all()
try:
with self.override_router():
to_del_qs.delete()
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Pet)
self.assertEqual(e.hints, {'instance': owner})
def test_reverse_fk_get_or_create(self):
owner = Person.objects.create(name='Someone')
try:
with self.override_router():
owner.pet_set.get_or_create(name='fido')
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Pet)
self.assertEqual(e.hints, {'instance': owner})
def test_reverse_fk_update(self):
owner = Person.objects.create(name='Someone')
Pet.objects.create(name='fido', owner=owner)
try:
with self.override_router():
owner.pet_set.update(name='max')
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Pet)
self.assertEqual(e.hints, {'instance': owner})
def test_m2m_add(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
try:
with self.override_router():
book.authors.add(auth)
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book.authors.through)
self.assertEqual(e.hints, {'instance': book})
def test_m2m_clear(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
book.authors.add(auth)
try:
with self.override_router():
book.authors.clear()
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book.authors.through)
self.assertEqual(e.hints, {'instance': book})
def test_m2m_delete(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
book.authors.add(auth)
try:
with self.override_router():
book.authors.all().delete()
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Person)
self.assertEqual(e.hints, {'instance': book})
def test_m2m_get_or_create(self):
Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
try:
with self.override_router():
book.authors.get_or_create(name='Someone else')
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book)
self.assertEqual(e.hints, {'instance': book})
def test_m2m_remove(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
book.authors.add(auth)
try:
with self.override_router():
book.authors.remove(auth)
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book.authors.through)
self.assertEqual(e.hints, {'instance': book})
def test_m2m_update(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
book.authors.add(auth)
try:
with self.override_router():
book.authors.all().update(name='Different')
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Person)
self.assertEqual(e.hints, {'instance': book})
def test_reverse_m2m_add(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
try:
with self.override_router():
auth.book_set.add(book)
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book.authors.through)
self.assertEqual(e.hints, {'instance': auth})
def test_reverse_m2m_clear(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
book.authors.add(auth)
try:
with self.override_router():
auth.book_set.clear()
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book.authors.through)
self.assertEqual(e.hints, {'instance': auth})
def test_reverse_m2m_delete(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
book.authors.add(auth)
try:
with self.override_router():
auth.book_set.all().delete()
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book)
self.assertEqual(e.hints, {'instance': auth})
def test_reverse_m2m_get_or_create(self):
auth = Person.objects.create(name='Someone')
Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
try:
with self.override_router():
auth.book_set.get_or_create(title="New Book", published=datetime.datetime.now())
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Person)
self.assertEqual(e.hints, {'instance': auth})
def test_reverse_m2m_remove(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
book.authors.add(auth)
try:
with self.override_router():
auth.book_set.remove(book)
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book.authors.through)
self.assertEqual(e.hints, {'instance': auth})
def test_reverse_m2m_update(self):
auth = Person.objects.create(name='Someone')
book = Book.objects.create(title="Pro Django",
published=datetime.date(2008, 12, 16))
book.authors.add(auth)
try:
with self.override_router():
auth.book_set.all().update(title='Different')
self.fail('db_for_write() not invoked on router')
except RouterUsed as e:
self.assertEqual(e.mode, RouterUsed.WRITE)
self.assertEqual(e.model, Book)
self.assertEqual(e.hints, {'instance': auth})