/tests/regressiontests/multiple_database/tests.py

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import datetime
import pickle
import sys
from StringIO import StringIO

from django.conf import settings
from django.contrib.auth.models import User
from django.core import management
from django.db import connections, router, DEFAULT_DB_ALIAS
from django.db.models import signals
from django.db.utils import ConnectionRouter
from django.test import TestCase

from models import Book, Person, Pet, Review, UserProfile

try:
    # we only have these models if the user is using multi-db, it's safe the
    # run the tests without them though.
    from models import Article, article_using
except ImportError:
    pass

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('"Dive Into Python" 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('"Dive Into Python" 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_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)),
                          [u'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)),
                          [u'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")

        # Retrive related object by descriptor. Related objects should be database-baound
        self.assertEqual(list(dive.authors.all().values_list('name', flat=True)),
                          [u'Mark Pilgrim'])

        self.assertEqual(list(mark.book_set.all().values_list('title', flat=True)),
                          [u'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)),
                          [u'Dive into Python'])
        self.assertEqual(list(Book.objects.using('other').filter(authors__name='John Smith').values_list('title', flat=True)),
                          [u'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)),
                          [u'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)),
                          [u'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)),
                          [u'Mark Pilgrim'])
        self.assertEqual(list(Person.objects.using('other').filter(book__title='Greasemonkey Hacks').values_list('name', flat=True)),
                          [u'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)),
                          [u'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)),
                          [u'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
        try:
            marty.book_set = [pro, dive]
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # Add to an m2m with an object from a different database
        try:
            marty.book_set.add(dive)
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # Set a m2m with an object from a different database
        try:
            marty.book_set = [pro, dive]
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # Add to a reverse m2m with an object from a different database
        try:
            dive.authors.add(marty)
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # Set a reverse m2m with an object from a different database
        try:
            dive.authors = [mark, marty]
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

    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))

        marty = Person.objects.create(name="Marty Alchin")
        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))

        mark = Person.objects.using('other').create(name="Mark Pilgrim")
        chris = Person.objects.using('other').create(name="Chris Mills")

        # Save the author's favourite 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)),
                          [u'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)),
                          [u'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")

        # Retrive related object by descriptor. Related objects should be database-baound
        self.assertEqual(list(chris.edited.values_list('title', flat=True)),
                          [u'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))

        mark = Person.objects.using('other').create(name="Mark Pilgrim")
        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)),
                          [u'Chris Mills'])
        self.assertEqual(list(Person.objects.using('other').filter(edited__title='Dive into Python').values_list('name', flat=True)),
                          [u'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)),
                          [u'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)),
                          [u'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))

        mark = Person.objects.using('other').create(name="Mark Pilgrim")

        # Set a foreign key with an object from a different database
        try:
            dive.editor = marty
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # Set a foreign key set with an object from a different database
        try:
            marty.edited = [pro, dive]
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # Add to a foreign key set with an object from a different database
        try:
            marty.edited.add(dive)
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # 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.
        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 'other'...
        dive.editor = chris
        html5.editor = mark
        self.assertEqual(chris._state.db, 'other')
        self.assertEqual(html5._state.db, 'other')
        # ... but it isn't saved yet
        self.assertEqual(list(Person.objects.using('other').values_list('name',flat=True)),
                          [u'Mark Pilgrim'])
        self.assertEqual(list(Book.objects.using('other').values_list('title',flat=True)),
                           [u'Dive into Python'])

        # When saved (no using required), new objects goes to 'other'
        chris.save()
        html5.save()
        self.assertEqual(list(Person.objects.using('default').values_list('name',flat=True)),
                          [u'Marty Alchin'])
        self.assertEqual(list(Person.objects.using('other').values_list('name',flat=True)),
                          [u'Chris Mills', u'Mark Pilgrim'])
        self.assertEqual(list(Book.objects.using('default').values_list('title',flat=True)),
                          [u'Pro Django'])
        self.assertEqual(list(Book.objects.using('other').values_list('title',flat=True)),
                          [u'Dive into HTML5', u'Dive into Python'])

        # 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, 'other')
        # ... but it isn't saved yet
        self.assertEqual(list(Book.objects.using('default').values_list('title',flat=True)),
                          [u'Pro Django'])
        self.assertEqual(list(Book.objects.using('other').values_list('title',flat=True)),
                          [u'Dive into HTML5', u'Dive into Python'])

        # When saved, the new book goes to 'other'
        water.save()
        self.assertEqual(list(Book.objects.using('default').values_list('title',flat=True)),
                          [u'Pro Django'])
        self.assertEqual(list(Book.objects.using('other').values_list('title',flat=True)),
                          [u'Dive into HTML5', u'Dive into Python', u'Dive into Water'])

    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")
        fido = 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.assertEqual(None, 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)),
                          [u'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)),
                          [u'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')

        # Retrive related object by descriptor. Related objects should be database-baound
        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')
        try:
            bob.userprofile = alice_profile
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # 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")

        charlie = User(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)),
                          [u'bob'])
        self.assertEqual(list(UserProfile.objects.using('other').values_list('flavor',flat=True)),
                           [u'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)),
                          [u'alice'])
        self.assertEqual(list(User.objects.using('other').values_list('username',flat=True)),
                          [u'bob', u'charlie'])
        self.assertEqual(list(UserProfile.objects.using('default').values_list('flavor',flat=True)),
                           [u'chocolate'])
        self.assertEqual(list(UserProfile.objects.using('other').values_list('flavor',flat=True)),
                           [u'crunchy frog', u'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)),
                           [u'chocolate'])
        self.assertEqual(list(UserProfile.objects.using('other').values_list('flavor',flat=True)),
                           [u'crunchy frog', u'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)),
                           [u'chocolate'])
        self.assertEqual(list(UserProfile.objects.using('other').values_list('flavor',flat=True)),
                           [u'crunchy frog', u'spring surprise', u'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")

        # Retrive related object by descriptor. Related objects should be database-bound
        self.assertEqual(list(dive.reviews.all().values_list('source', flat=True)),
                          [u'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)),
                          [u'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)),
                          [u'Python Monthly', u'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)),
                          [u'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)),
                          [u'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))

        review2 = Review.objects.using('other').create(source="Python Weekly", content_object=dive)

        # Set a foreign key with an object from a different database
        try:
            review1.content_object = dive
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # Add to a foreign key set with an object from a different database
        try:
            dive.reviews.add(review1)
            self.fail("Shouldn't be able to assign across databases")
        except ValueError:
            pass

        # 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)),
                          [u'Python Monthly'])
        self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source',flat=True)),
                          [u'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)),
                          [u'Python Monthly'])
        self.assertEqual(list(Review.objects.using('other').filter(object_id=dive.pk).values_list('source',flat=True)),
                          [u'Python Daily', u'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 = 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"
        pro = 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.assertEqual(map(lambda o: o.pk, val), [dive.pk])

        val = Book.objects.raw('SELECT id FROM multiple_database_book').using('other')
        self.assertEqual(map(lambda o: o.pk, val), [dive.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")
        dive = 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 master/slave."""
        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
        try:
            for obj in qs:
                pass
            self.fail('Iterating over query should raise ValueError')
        except ValueError:
            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 TestRouter(object):
    # A test router. The behaviour is vaguely master/slave, but the
    # databases aren't assumed to propagate changes.
    def db_for_read(self, model, instance=None, **hints):
        if instance:
            return instance._state.db or 'other'
        return 'other'

    def db_for_write(self, model, **hints):
        return DEFAULT_DB_ALIAS

    def allow_relation(self, obj1, obj2, **hints):
        return obj1._state.db in ('default', 'other') and obj2._state.db in ('default', 'other')

    def allow_syncdb(self, db, model):
        return True

class AuthRouter(object):
    """A router to control all database operations on models in
    the contrib.auth application"""

    def db_for_read(self, model, **hints):
        "Point all read operations on auth models to 'default'"
        if model._meta.app_label == 'auth':
            # We use default here to ensure we can tell the difference
            # between a read request and a write request for Auth objects
            return 'default'
        return None

    def db_for_write(self, model, **hints):
        "Point all operations on auth models to 'other'"
        if model._meta.app_label == 'auth':
            return 'other'
        return None

    def allow_relation(self, obj1, obj2, **hints):
        "Allow any relation if a model in Auth is involved"
        if obj1._meta.app_label == 'auth' or obj2._meta.app_label == 'auth':
            return True
        return None

    def allow_syncdb(self, db, model):
        "Make sure the auth app only appears on the 'other' db"
        if db == 'other':
            return model._meta.app_label == 'auth'
        elif model._meta.app_label == 'auth':
            return False
        return None

class WriteRouter(object):
    # A router that only expresses an opinion on writes
    def db_for_write(self, model, **hints):
        return 'writer'

class RouterTestCase(TestCase):
    multi_db = True

    def setUp(self):
        # Make the 'other' database appear to be a slave of the 'default'
        self.old_routers = router.routers
        router.routers = [TestRouter()]

    def tearDown(self):
        # Restore the 'other' database as an independent database
        router.routers = self.old_routers

    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_syncdb_selection(self):
        "Synchronization behaviour is predicatable"

        self.assertTrue(router.allow_syncdb('default', User))
        self.assertTrue(router.allow_syncdb('default', Book))

        self.assertTrue(router.allow_syncdb('other', User))
        self.assertTrue(router.allow_syncdb('other', Book))

        # Add the auth router to the chain.
        # TestRouter is a universal synchronizer, so it should have no effect.
        router.routers = [TestRouter(), AuthRouter()]

        self.assertTrue(router.allow_syncdb('default', User))
        self.assertTrue(router.allow_syncdb('default', Book))

        self.assertTrue(router.allow_syncdb('other', User))
        self.assertTrue(router.allow_syncdb('other', Book))

        # Now check what happens if the router order is the other way around
        router.routers = [AuthRouter(), TestRouter()]

        self.assertFalse(router.allow_syncdb('default', User))
        self.assertTrue(router.allow_syncdb('default', Book))

        self.assertTrue(router.allow_syncdb('other', User))
        self.assertFalse(router.allow_syncdb('other', Book))

    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 behaviour

        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_syncdb('default', User))
        self.assertTrue(router.allow_syncdb('default', Book))

        router.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_relatio…