write.py

from unittest import skipIf, skipUnless

from django import VERSION as DJANGO_VERSION
from django.contrib.auth.models import User, Permission, Group
from django.contrib.contenttypes.models import ContentType
from django.core.exceptions import MultipleObjectsReturned
from django.core.management import call_command
from django.db import (
    connection, transaction, ProgrammingError, OperationalError)
from django.db.models import Count
from django.db.models.expressions import RawSQL
from django.test import TransactionTestCase, skipUnlessDBFeature

from .models import Test, TestParent, TestChild
from .test_utils import TestUtilsMixin


class WriteTestCase(TestUtilsMixin, TransactionTestCase):
    """
    Tests if every SQL request writing data is not cached and invalidates the
    implied data.
    """

    def test_create(self):
        with self.assertNumQueries(1):
            data1 = list(Test.objects.all())
        self.assertListEqual(data1, [])

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t1 = Test.objects.create(name='test1')
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t2 = Test.objects.create(name='test2')

        with self.assertNumQueries(1):
            data2 = list(Test.objects.all())
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t3 = Test.objects.create(name='test3')
        with self.assertNumQueries(1):
            data3 = list(Test.objects.all())
        self.assertListEqual(data2, [t1, t2])
        self.assertListEqual(data3, [t1, t2, t3])

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t3_copy = Test.objects.create(name='test3')
        self.assertNotEqual(t3_copy, t3)
        with self.assertNumQueries(1):
            data4 = list(Test.objects.all())
        self.assertListEqual(data4, [t1, t2, t3, t3_copy])

    def test_get_or_create(self):
        """
        Tests if the ``SELECT`` query of a ``QuerySet.get_or_create``
        is cached, but not the ``INSERT`` one.
        """
        with self.assertNumQueries(1):
            data1 = list(Test.objects.all())
        self.assertListEqual(data1, [])

        with self.assertNumQueries(3 if self.is_sqlite else 2):
            t, created = Test.objects.get_or_create(name='test')
        self.assertTrue(created)

        with self.assertNumQueries(1):
            t_clone, created = Test.objects.get_or_create(name='test')
        self.assertFalse(created)
        self.assertEqual(t_clone, t)

        with self.assertNumQueries(0):
            t_clone, created = Test.objects.get_or_create(name='test')
        self.assertFalse(created)
        self.assertEqual(t_clone, t)

        with self.assertNumQueries(1):
            data2 = list(Test.objects.all())
        self.assertListEqual(data2, [t])

    def test_update_or_create(self):
        with self.assertNumQueries(1):
            self.assertListEqual(list(Test.objects.all()), [])

        with self.assertNumQueries(5 if self.is_sqlite else 4):
            t, created = Test.objects.update_or_create(
                name='test', defaults={'public': True})
            self.assertTrue(created)
            self.assertEqual(t.name, 'test')
            self.assertEqual(t.public, True)

        with self.assertNumQueries(3 if self.is_sqlite else 2):
            t, created = Test.objects.update_or_create(
                name='test', defaults={'public': False})
            self.assertFalse(created)
            self.assertEqual(t.name, 'test')
            self.assertEqual(t.public, False)

        # The number of SQL queries doesn’t decrease because update_or_create
        # always calls an UPDATE, even when data wasn’t changed.
        with self.assertNumQueries(3 if self.is_sqlite else 2):
            t, created = Test.objects.update_or_create(
                name='test', defaults={'public': False})
            self.assertFalse(created)
            self.assertEqual(t.name, 'test')
            self.assertEqual(t.public, False)

        with self.assertNumQueries(1):
            self.assertListEqual(list(Test.objects.all()), [t])

    def test_bulk_create(self):
        with self.assertNumQueries(1):
            data1 = list(Test.objects.all())
        self.assertListEqual(data1, [])

        with self.assertNumQueries(2 if self.is_sqlite else 1):
            unsaved_tests = [Test(name='test%02d' % i) for i in range(1, 11)]
            Test.objects.bulk_create(unsaved_tests)
        self.assertEqual(Test.objects.count(), 10)

        with self.assertNumQueries(2 if self.is_sqlite else 1):
            unsaved_tests = [Test(name='test%02d' % i) for i in range(1, 11)]
            Test.objects.bulk_create(unsaved_tests)
        self.assertEqual(Test.objects.count(), 20)

        with self.assertNumQueries(1):
            data2 = list(Test.objects.all())
        self.assertEqual(len(data2), 20)
        self.assertListEqual([t.name for t in data2],
                             ['test%02d' % (i // 2) for i in range(2, 22)])

    def test_update(self):
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t = Test.objects.create(name='test1')

        with self.assertNumQueries(1):
            t1 = Test.objects.get()
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t.name = 'test2'
            t.save()
        with self.assertNumQueries(1):
            t2 = Test.objects.get()
        self.assertEqual(t1.name, 'test1')
        self.assertEqual(t2.name, 'test2')

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            Test.objects.update(name='test3')
        with self.assertNumQueries(1):
            t3 = Test.objects.get()
        self.assertEqual(t3.name, 'test3')

    def test_delete(self):
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t1 = Test.objects.create(name='test1')
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t2 = Test.objects.create(name='test2')

        with self.assertNumQueries(1):
            data1 = list(Test.objects.values_list('name', flat=True))
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t2.delete()
        with self.assertNumQueries(1):
            data2 = list(Test.objects.values_list('name', flat=True))
        self.assertListEqual(data1, [t1.name, t2.name])
        self.assertListEqual(data2, [t1.name])

        with self.assertNumQueries(2 if self.is_sqlite else 1):
            Test.objects.bulk_create([Test(name='test%s' % i)
                                      for i in range(2, 11)])
        with self.assertNumQueries(1):
            self.assertEqual(Test.objects.count(), 10)
        with self.assertNumQueries(2 if self.is_sqlite else 1):
            Test.objects.all().delete()
        with self.assertNumQueries(1):
            self.assertEqual(Test.objects.count(), 0)

    def test_invalidate_exists(self):
        with self.assertNumQueries(1):
            self.assertFalse(Test.objects.exists())

        Test.objects.create(name='test')

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            self.assertTrue(Test.objects.create())

    def test_invalidate_count(self):
        with self.assertNumQueries(1):
            self.assertEqual(Test.objects.count(), 0)

        Test.objects.create(name='test1')

        with self.assertNumQueries(1):
            self.assertEqual(Test.objects.count(), 1)

        Test.objects.create(name='test2')

        with self.assertNumQueries(1):
            self.assertEqual(Test.objects.count(), 2)

    def test_invalidate_get(self):
        with self.assertNumQueries(1):
            with self.assertRaises(Test.DoesNotExist):
                Test.objects.get(name='test')

        Test.objects.create(name='test')

        with self.assertNumQueries(1):
            Test.objects.get(name='test')

        Test.objects.create(name='test')

        with self.assertNumQueries(1):
            with self.assertRaises(MultipleObjectsReturned):
                Test.objects.get(name='test')

    def test_invalidate_values(self):
        with self.assertNumQueries(1):
            data1 = list(Test.objects.values('name', 'public'))
        self.assertListEqual(data1, [])

        Test.objects.bulk_create([Test(name='test1'),
                                  Test(name='test2', public=True)])

        with self.assertNumQueries(1):
            data2 = list(Test.objects.values('name', 'public'))
        self.assertEqual(len(data2), 2)
        self.assertDictEqual(data2[0], {'name': 'test1', 'public': False})
        self.assertDictEqual(data2[1], {'name': 'test2', 'public': True})

        Test.objects.all()[0].delete()

        with self.assertNumQueries(1):
            data3 = list(Test.objects.values('name', 'public'))
        self.assertEqual(len(data3), 1)
        self.assertDictEqual(data3[0], {'name': 'test2', 'public': True})

    def test_invalidate_foreign_key(self):
        with self.assertNumQueries(1):
            data1 = [t.owner.username for t in Test.objects.all() if t.owner]
        self.assertListEqual(data1, [])

        u1 = User.objects.create_user('user1')
        Test.objects.bulk_create([Test(name='test1', owner=u1),
                                  Test(name='test2')])

        with self.assertNumQueries(2):
            data2 = [t.owner.username for t in Test.objects.all() if t.owner]
        self.assertListEqual(data2, ['user1'])

        Test.objects.create(name='test3')

        with self.assertNumQueries(1):
            data3 = [t.owner.username for t in Test.objects.all() if t.owner]
        self.assertListEqual(data3, ['user1'])

        t2 = Test.objects.get(name='test2')
        t2.owner = u1
        t2.save()

        with self.assertNumQueries(1):
            data4 = [t.owner.username for t in Test.objects.all() if t.owner]
        self.assertListEqual(data4, ['user1', 'user1'])

        u2 = User.objects.create_user('user2')
        Test.objects.filter(name='test3').update(owner=u2)

        with self.assertNumQueries(3):
            data5 = [t.owner.username for t in Test.objects.all() if t.owner]
        self.assertListEqual(data5, ['user1', 'user1', 'user2'])

        User.objects.filter(username='user2').update(username='user3')

        with self.assertNumQueries(2):
            data6 = [t.owner.username for t in Test.objects.all() if t.owner]
        self.assertListEqual(data6, ['user1', 'user1', 'user3'])

        u2 = User.objects.create_user('user2')
        Test.objects.filter(name='test2').update(owner=u2)

        with self.assertNumQueries(4):
            data7 = [t.owner.username for t in Test.objects.all() if t.owner]
        self.assertListEqual(data7, ['user1', 'user2', 'user3'])

        with self.assertNumQueries(0):
            data8 = [t.owner.username for t in Test.objects.all() if t.owner]
        self.assertListEqual(data8, ['user1', 'user2', 'user3'])

    def test_invalidate_many_to_many(self):
        u = User.objects.create_user('test_user')
        ct = ContentType.objects.get_for_model(User)
        discuss = Permission.objects.create(
            name='Can discuss', content_type=ct, codename='discuss')
        touch = Permission.objects.create(
            name='Can touch', content_type=ct, codename='touch')
        cuddle = Permission.objects.create(
            name='Can cuddle', content_type=ct, codename='cuddle')
        u.user_permissions.add(discuss, touch, cuddle)
        with self.assertNumQueries(1):
            data1 = [p.codename for p in u.user_permissions.all()]
        self.assertListEqual(data1, ['cuddle', 'discuss', 'touch'])

        touch.name = 'Can lick'
        touch.codename = 'lick'
        touch.save()

        with self.assertNumQueries(1):
            data2 = [p.codename for p in u.user_permissions.all()]
        self.assertListEqual(data2, ['cuddle', 'discuss', 'lick'])

        Permission.objects.filter(pk=discuss.pk).update(
            name='Can finger', codename='finger')

        with self.assertNumQueries(1):
            data3 = [p.codename for p in u.user_permissions.all()]
        self.assertListEqual(data3, ['cuddle', 'finger', 'lick'])

    def test_invalidate_aggregate(self):
        with self.assertNumQueries(1):
            self.assertEqual(User.objects.aggregate(n=Count('test'))['n'], 0)

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            u = User.objects.create_user('test')
        with self.assertNumQueries(1):
            self.assertEqual(User.objects.aggregate(n=Count('test'))['n'], 0)

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            Test.objects.create(name='test1')
        with self.assertNumQueries(1):
            self.assertEqual(User.objects.aggregate(n=Count('test'))['n'], 0)

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            Test.objects.create(name='test2', owner=u)
        with self.assertNumQueries(1):
            self.assertEqual(User.objects.aggregate(n=Count('test'))['n'], 1)

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            Test.objects.create(name='test3')
        with self.assertNumQueries(1):
            self.assertEqual(User.objects.aggregate(n=Count('test'))['n'], 1)

    def test_invalidate_annotate(self):
        with self.assertNumQueries(1):
            data1 = list(User.objects.annotate(n=Count('test')).order_by('pk'))
        self.assertListEqual(data1, [])

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            Test.objects.create(name='test1')
        with self.assertNumQueries(1):
            data2 = list(User.objects.annotate(n=Count('test')).order_by('pk'))
        self.assertListEqual(data2, [])

        with self.assertNumQueries(4 if self.is_dj_21_below_and_is_sqlite() else 2):
            user1 = User.objects.create_user('user1')
            user2 = User.objects.create_user('user2')
        with self.assertNumQueries(1):
            data3 = list(User.objects.annotate(n=Count('test')).order_by('pk'))
        self.assertListEqual(data3, [user1, user2])
        self.assertListEqual([u.n for u in data3], [0, 0])

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            Test.objects.create(name='test2', owner=user1)
        with self.assertNumQueries(1):
            data4 = list(User.objects.annotate(n=Count('test')).order_by('pk'))
        self.assertListEqual(data4, [user1, user2])
        self.assertListEqual([u.n for u in data4], [1, 0])

        with self.assertNumQueries(2 if self.is_sqlite else 1):
            Test.objects.bulk_create([
                Test(name='test3', owner=user1),
                Test(name='test4', owner=user2),
                Test(name='test5', owner=user1),
                Test(name='test6', owner=user2),
            ])
        with self.assertNumQueries(1):
            data5 = list(User.objects.annotate(n=Count('test')).order_by('pk'))
        self.assertListEqual(data5, [user1, user2])
        self.assertListEqual([u.n for u in data5], [3, 2])

    def test_invalidate_subquery(self):
        with self.assertNumQueries(1):
            data1 = list(Test.objects.filter(owner__in=User.objects.all()))
        self.assertListEqual(data1, [])

        u = User.objects.create_user('test')

        with self.assertNumQueries(1):
            data2 = list(Test.objects.filter(owner__in=User.objects.all()))
        self.assertListEqual(data2, [])

        t = Test.objects.create(name='test', owner=u)

        with self.assertNumQueries(1):
            data3 = list(Test.objects.filter(owner__in=User.objects.all()))
        self.assertListEqual(data3, [t])

        with self.assertNumQueries(1):
            data4 = list(
                Test.objects.filter(
                    owner__groups__permissions__in=Permission.objects.all()
                ).distinct())
        self.assertListEqual(data4, [])

        g = Group.objects.create(name='test_group')

        with self.assertNumQueries(1):
            data5 = list(
                Test.objects.filter(
                    owner__groups__permissions__in=Permission.objects.all()
                ).distinct())
        self.assertListEqual(data5, [])

        p = Permission.objects.first()
        g.permissions.add(p)

        with self.assertNumQueries(1):
            data6 = list(
                Test.objects.filter(
                    owner__groups__permissions__in=Permission.objects.all()
                ).distinct())
        self.assertListEqual(data6, [])

        u.groups.add(g)

        with self.assertNumQueries(1):
            data7 = list(
                Test.objects.filter(
                    owner__groups__permissions__in=Permission.objects.all()
                ).distinct())
        self.assertListEqual(data7, [t])

        with self.assertNumQueries(1):
            data8 = list(
                User.objects.filter(user_permissions__in=g.permissions.all())
            )
        self.assertListEqual(data8, [])

        u.user_permissions.add(p)

        with self.assertNumQueries(1):
            data9 = list(
                User.objects.filter(user_permissions__in=g.permissions.all())
            )
        self.assertListEqual(data9, [u])

        g.permissions.remove(p)

        with self.assertNumQueries(1):
            data10 = list(
                User.objects.filter(user_permissions__in=g.permissions.all())
            )
        self.assertListEqual(data10, [])

        with self.assertNumQueries(1):
            data11 = list(User.objects.exclude(user_permissions=None))
        self.assertListEqual(data11, [u])

        u.user_permissions.clear()

        with self.assertNumQueries(1):
            data12 = list(User.objects.exclude(user_permissions=None))
        self.assertListEqual(data12, [])

    def test_invalidate_nested_subqueries(self):
        with self.assertNumQueries(1):
            data1 = list(
                User.objects.filter(
                    pk__in=User.objects.filter(
                        user_permissions__in=Permission.objects.all()
                    )
                )
            )
        self.assertListEqual(data1, [])

        u = User.objects.create_user('test')

        with self.assertNumQueries(1):
            data2 = list(
                User.objects.filter(
                    pk__in=User.objects.filter(
                        user_permissions__in=Permission.objects.all()
                    )
                )
            )
        self.assertListEqual(data2, [])

        p = Permission.objects.first()
        u.user_permissions.add(p)

        with self.assertNumQueries(1):
            data3 = list(
                User.objects.filter(
                    pk__in=User.objects.filter(
                        user_permissions__in=Permission.objects.all()
                    )
                )
            )
        self.assertListEqual(data3, [u])

        with self.assertNumQueries(1):
            data4 = list(
                User.objects.filter(
                    pk__in=User.objects.filter(
                        pk__in=User.objects.filter(
                            user_permissions__in=Permission.objects.all()
                        )
                    )
                )
            )
        self.assertListEqual(data4, [u])

        u.user_permissions.remove(p)

        with self.assertNumQueries(1):
            data5 = list(
                User.objects.filter(
                    pk__in=User.objects.filter(
                        pk__in=User.objects.filter(
                            user_permissions__in=Permission.objects.all()
                        )
                    )
                )
            )
        self.assertListEqual(data5, [])

    def test_invalidate_raw_subquery(self):
        permission = Permission.objects.first()
        with self.assertNumQueries(0):
            raw_sql = RawSQL('SELECT id FROM auth_permission WHERE id = %s',
                             (permission.pk,))
        with self.assertNumQueries(1):
            data1 = list(Test.objects.filter(permission=raw_sql))
        self.assertListEqual(data1, [])

        test = Test.objects.create(name='test', permission=permission)

        with self.assertNumQueries(1):
            data2 = list(Test.objects.filter(permission=raw_sql))
        self.assertListEqual(data2, [test])

        permission.save()

        with self.assertNumQueries(1):
            data3 = list(Test.objects.filter(permission=raw_sql))
        self.assertListEqual(data3, [test])

        test.delete()

        with self.assertNumQueries(1):
            data4 = list(Test.objects.filter(permission=raw_sql))
        self.assertListEqual(data4, [])

    def test_invalidate_nested_raw_subquery(self):
        permission = Permission.objects.first()
        with self.assertNumQueries(0):
            raw_sql = RawSQL('SELECT id FROM auth_permission WHERE id = %s',
                             (permission.pk,))
        with self.assertNumQueries(1):
            data1 = list(Test.objects.filter(
                pk__in=Test.objects.filter(permission=raw_sql)))
        self.assertListEqual(data1, [])

        test = Test.objects.create(name='test', permission=permission)

        with self.assertNumQueries(1):
            data2 = list(Test.objects.filter(
                pk__in=Test.objects.filter(permission=raw_sql)))
        self.assertListEqual(data2, [test])

        permission.save()

        with self.assertNumQueries(1):
            data3 = list(Test.objects.filter(
                pk__in=Test.objects.filter(permission=raw_sql)))
        self.assertListEqual(data3, [test])

        test.delete()

        with self.assertNumQueries(1):
            data4 = list(Test.objects.filter(
                pk__in=Test.objects.filter(permission=raw_sql)))
        self.assertListEqual(data4, [])

    def test_invalidate_select_related(self):
        with self.assertNumQueries(1):
            data1 = list(Test.objects.select_related('owner'))
        self.assertListEqual(data1, [])

        with self.assertNumQueries(4 if self.is_dj_21_below_and_is_sqlite() else 2):
            u1 = User.objects.create_user('test1')
            u2 = User.objects.create_user('test2')
        with self.assertNumQueries(1):
            data2 = list(Test.objects.select_related('owner'))
        self.assertListEqual(data2, [])

        with self.assertNumQueries(2 if self.is_sqlite else 1):
            Test.objects.bulk_create([
                Test(name='test1', owner=u1),
                Test(name='test2', owner=u2),
                Test(name='test3', owner=u2),
                Test(name='test4', owner=u1),
            ])
        with self.assertNumQueries(1):
            data3 = list(Test.objects.select_related('owner'))
            self.assertEqual(data3[0].owner, u1)
            self.assertEqual(data3[1].owner, u2)
            self.assertEqual(data3[2].owner, u2)
            self.assertEqual(data3[3].owner, u1)

        with self.assertNumQueries(2 if self.is_sqlite else 1):
            Test.objects.filter(name__in=['test1', 'test2']).delete()
        with self.assertNumQueries(1):
            data4 = list(Test.objects.select_related('owner'))
            self.assertEqual(data4[0].owner, u2)
            self.assertEqual(data4[1].owner, u1)

    def test_invalidate_prefetch_related(self):
        with self.assertNumQueries(1):
            data1 = list(Test.objects.select_related('owner')
                         .prefetch_related('owner__groups__permissions'))
            self.assertListEqual(data1, [])

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t1 = Test.objects.create(name='test1')
        with self.assertNumQueries(1):
            data2 = list(Test.objects.select_related('owner')
                         .prefetch_related('owner__groups__permissions'))
            self.assertListEqual(data2, [t1])
            self.assertEqual(data2[0].owner, None)

        with self.assertNumQueries(4 if self.is_dj_21_below_and_is_sqlite() else 2):
            u = User.objects.create_user('user')
            t1.owner = u
            t1.save()
        with self.assertNumQueries(2):
            data3 = list(Test.objects.select_related('owner')
                         .prefetch_related('owner__groups__permissions'))
            self.assertListEqual(data3, [t1])
            self.assertEqual(data3[0].owner, u)
            self.assertListEqual(list(data3[0].owner.groups.all()), [])

        with self.assertNumQueries(
                9 if self.is_dj_21_below_and_is_sqlite()
                else 8 if self.is_sqlite and DJANGO_VERSION[0] == 2 and DJANGO_VERSION[1] == 2
                else 4 if self.is_postgresql and DJANGO_VERSION[0] > 2
                else 4 if self.is_mysql and DJANGO_VERSION[0] > 2
                else 6
        ):
            group = Group.objects.create(name='test_group')
            permissions = list(Permission.objects.all()[:5])
            group.permissions.add(*permissions)
            u.groups.add(group)
        with self.assertNumQueries(2):
            data4 = list(Test.objects.select_related('owner')
                         .prefetch_related('owner__groups__permissions'))
            self.assertListEqual(data4, [t1])
            owner = data4[0].owner
            self.assertEqual(owner, u)
            groups = list(owner.groups.all())
            self.assertListEqual(groups, [group])
            self.assertListEqual(list(groups[0].permissions.all()),
                                 permissions)

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t2 = Test.objects.create(name='test2')
        with self.assertNumQueries(1):
            data5 = list(Test.objects.select_related('owner')
                         .prefetch_related('owner__groups__permissions'))
            self.assertListEqual(data5, [t1, t2])
            owners = [t.owner for t in data5 if t.owner is not None]
            self.assertListEqual(owners, [u])
            groups = [g for o in owners for g in o.groups.all()]
            self.assertListEqual(groups, [group])
            data5_permissions = [p for g in groups
                                 for p in g.permissions.all()]
            self.assertListEqual(data5_permissions, permissions)

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            permissions[0].save()
        with self.assertNumQueries(1):
            list(Test.objects.select_related('owner')
                 .prefetch_related('owner__groups__permissions'))

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            group.name = 'modified_test_group'
            group.save()
        with self.assertNumQueries(2):
            data6 = list(Test.objects.select_related('owner')
                         .prefetch_related('owner__groups__permissions'))
            g = list(data6[0].owner.groups.all())[0]
            self.assertEqual(g.name, 'modified_test_group')

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            User.objects.update(username='modified_user')

        with self.assertNumQueries(2):
            data7 = list(Test.objects.select_related('owner')
                         .prefetch_related('owner__groups__permissions'))
            self.assertEqual(data7[0].owner.username, 'modified_user')

    @skipUnlessDBFeature('has_select_for_update')
    def test_invalidate_select_for_update(self):
        with self.assertNumQueries(1):
            Test.objects.bulk_create([Test(name='test1'), Test(name='test2')])

        with self.assertNumQueries(1):
            with transaction.atomic():
                data1 = list(Test.objects.select_for_update())
                self.assertListEqual([t.name for t in data1],
                                     ['test1', 'test2'])

        with self.assertNumQueries(1):
            with transaction.atomic():
                qs = Test.objects.select_for_update()
                qs.update(name='test3')

        with self.assertNumQueries(1):
            with transaction.atomic():
                data2 = list(Test.objects.select_for_update())
                self.assertListEqual([t.name for t in data2], ['test3'] * 2)

    def test_invalidate_extra_select(self):
        user = User.objects.create_user('user')
        t1 = Test.objects.create(name='test1', owner=user, public=True)

        username_length_sql = """
            SELECT LENGTH(%(user_table)s.username)
            FROM %(user_table)s
            WHERE %(user_table)s.id = %(test_table)s.owner_id
            """ % {'user_table': User._meta.db_table,
                   'test_table': Test._meta.db_table}

        with self.assertNumQueries(1):
            data1 = list(Test.objects.extra(
                select={'username_length': username_length_sql}))
            self.assertListEqual(data1, [t1])
            self.assertListEqual([o.username_length for o in data1], [4])

        Test.objects.update(public=False)

        with self.assertNumQueries(1):
            data2 = list(Test.objects.extra(
                select={'username_length': username_length_sql}))
            self.assertListEqual(data2, [t1])
            self.assertListEqual([o.username_length for o in data2], [4])

        admin = User.objects.create_superuser('admin',
                                              'admin@test.me', 'password')

        with self.assertNumQueries(1):
            data3 = list(Test.objects.extra(
                select={'username_length': username_length_sql}))
            self.assertListEqual(data3, [t1])
            self.assertListEqual([o.username_length for o in data3], [4])

        t2 = Test.objects.create(name='test2', owner=admin)

        with self.assertNumQueries(1):
            data4 = list(Test.objects.extra(
                select={'username_length': username_length_sql}))
            self.assertListEqual(data4, [t1, t2])
            self.assertListEqual([o.username_length for o in data4], [4, 5])

    def test_invalidate_having(self):
        with self.assertNumQueries(1):
            data1 = list(User.objects.annotate(n=Count('user_permissions'))
                         .filter(n__gte=1))
            self.assertListEqual(data1, [])

        u = User.objects.create_user('user')

        with self.assertNumQueries(1):
            data2 = list(User.objects.annotate(n=Count('user_permissions'))
                         .filter(n__gte=1))
            self.assertListEqual(data2, [])

        p = Permission.objects.first()
        p.save()

        with self.assertNumQueries(1):
            data3 = list(User.objects.annotate(n=Count('user_permissions'))
                         .filter(n__gte=1))
            self.assertListEqual(data3, [])

        u.user_permissions.add(p)

        with self.assertNumQueries(1):
            data3 = list(User.objects.annotate(n=Count('user_permissions'))
                         .filter(n__gte=1))
            self.assertListEqual(data3, [u])

        with self.assertNumQueries(1):
            self.assertEqual(User.objects.annotate(n=Count('user_permissions'))
                             .filter(n__gte=1).count(), 1)

        u.user_permissions.clear()

        with self.assertNumQueries(1):
            self.assertEqual(User.objects.annotate(n=Count('user_permissions'))
                             .filter(n__gte=1).count(), 0)

    def test_invalidate_extra_where(self):
        sql_condition = ("owner_id IN "
                         "(SELECT id FROM auth_user WHERE username = 'admin')")
        with self.assertNumQueries(1):
            data1 = list(Test.objects.extra(where=[sql_condition]))
            self.assertListEqual(data1, [])

        admin = User.objects.create_superuser('admin',
                                              'admin@test.me', 'password')

        with self.assertNumQueries(1):
            data2 = list(Test.objects.extra(where=[sql_condition]))
            self.assertListEqual(data2, [])

        t = Test.objects.create(name='test', owner=admin)

        with self.assertNumQueries(1):
            data3 = list(Test.objects.extra(where=[sql_condition]))
            self.assertListEqual(data3, [t])

        admin.username = 'modified'
        admin.save()

        with self.assertNumQueries(1):
            data4 = list(Test.objects.extra(where=[sql_condition]))
            self.assertListEqual(data4, [])

    def test_invalidate_extra_tables(self):
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            User.objects.create_user('user1')

        with self.assertNumQueries(1):
            data1 = list(Test.objects.all().extra(tables=['auth_user']))
        self.assertListEqual(data1, [])

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t1 = Test.objects.create(name='test1')
        with self.assertNumQueries(1):
            data2 = list(Test.objects.all().extra(tables=['auth_user']))
        self.assertListEqual(data2, [t1])

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            t2 = Test.objects.create(name='test2')
        with self.assertNumQueries(1):
            data3 = list(Test.objects.all().extra(tables=['auth_user']))
        self.assertListEqual(data3, [t1, t2])

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            User.objects.create_user('user2')
        with self.assertNumQueries(1):
            data4 = list(Test.objects.all().extra(tables=['auth_user']))
        self.assertListEqual(data4, [t1, t1, t2, t2])

    def test_invalidate_extra_order_by(self):
        with self.assertNumQueries(1):
            data1 = list(Test.objects.extra(order_by=['-cachalot_test.name']))
            self.assertListEqual(data1, [])
        t1 = Test.objects.create(name='test1')
        with self.assertNumQueries(1):
            data2 = list(Test.objects.extra(order_by=['-cachalot_test.name']))
            self.assertListEqual(data2, [t1])
        t2 = Test.objects.create(name='test2')
        with self.assertNumQueries(1):
            data2 = list(Test.objects.extra(order_by=['-cachalot_test.name']))
            self.assertListEqual(data2, [t2, t1])

    def test_invalidate_table_inheritance(self):
        with self.assertNumQueries(1):
            with self.assertRaises(TestChild.DoesNotExist):
                TestChild.objects.get()

        with self.assertNumQueries(3 if self.is_sqlite else 2):
            t_child = TestChild.objects.create(name='test_child')

        with self.assertNumQueries(1):
            self.assertEqual(TestChild.objects.get(), t_child)

        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            TestParent.objects.filter(pk=t_child.pk).update(name='modified')

        with self.assertNumQueries(1):
            modified_t_child = TestChild.objects.get()
            self.assertEqual(modified_t_child.pk, t_child.pk)
            self.assertEqual(modified_t_child.name, 'modified')

        with self.assertNumQueries(3 if self.is_dj_21_below_and_is_sqlite() else 2):
            TestChild.objects.filter(pk=t_child.pk).update(name='modified2')

        with self.assertNumQueries(1):
            modified2_t_child = TestChild.objects.get()
            self.assertEqual(modified2_t_child.pk, t_child.pk)
            self.assertEqual(modified2_t_child.name, 'modified2')

    def test_raw_insert(self):
        with self.assertNumQueries(1):
            self.assertListEqual(
                list(Test.objects.values_list('name', flat=True)),
                [])

        with self.assertNumQueries(1):
            with connection.cursor() as cursor:
                cursor.execute(
                    "INSERT INTO cachalot_test (name, public) "
                    "VALUES ('test1', %s)", [1 if self.is_dj_21_below_and_is_sqlite() else True])

        with self.assertNumQueries(1):
            self.assertListEqual(
                list(Test.objects.values_list('name', flat=True)),
                ['test1'])

        with self.assertNumQueries(1):
            with connection.cursor() as cursor:
                cursor.execute(
                    "INSERT INTO cachalot_test (name, public) "
                    "VALUES ('test2', %s)", [1 if self.is_dj_21_below_and_is_sqlite() else True])

        with self.assertNumQueries(1):
            self.assertListEqual(
                list(Test.objects.values_list('name', flat=True)),
                ['test1', 'test2'])

        with self.assertNumQueries(1):
            with connection.cursor() as cursor:
                cursor.executemany(
                    "INSERT INTO cachalot_test (name, public) "
                    "VALUES ('test3', %s)", [[1 if self.is_dj_21_below_and_is_sqlite() else True]])

        with self.assertNumQueries(1):
            self.assertListEqual(
                list(Test.objects.values_list('name', flat=True)),
                ['test1', 'test2', 'test3'])

    def test_raw_update(self):
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            Test.objects.create(name='test')
        with self.assertNumQueries(1):
            self.assertListEqual(
                list(Test.objects.values_list('name', flat=True)),
                ['test'])

        with self.assertNumQueries(1):
            with connection.cursor() as cursor:
                cursor.execute("UPDATE cachalot_test SET name = 'new name';")

        with self.assertNumQueries(1):
            self.assertListEqual(
                list(Test.objects.values_list('name', flat=True)),
                ['new name'])

    def test_raw_delete(self):
        with self.assertNumQueries(2 if self.is_dj_21_below_and_is_sqlite() else 1):
            Test.objects.create(name='test')
        with self.assertNumQueries(1):
            self.assertListEqual(
                list(Test.objects.values_list('name', flat=True)),
                ['test'])

        with self.assertNumQueries(1):
            with connection.cursor() as cursor:
                cursor.execute('DELETE FROM cachalot_test;')

        with self.assertNumQueries(1):
            self.assertListEqual(
                list(Test.objects.values_list('name', flat=True)),
                [])

    def test_raw_create(self):
        with self.assertNumQueries(1):
            self.assertListEqual(list(Test.objects.all()), [])

        try:
            with self.assertNumQueries(1):
                with connection.cursor() as cursor:
                    cursor.execute(
                        'CREATE INDEX tmp_index ON cachalot_test(name);')

            with self.assertNumQueries(1):
                self.assertListEqual(list(Test.objects.all()), [])
        finally:
            with connection.cursor() as cursor:
                cursor.execute('DROP INDEX tmp_index ON cachalot_test;'
                               if self.is_mysql else 'DROP INDEX tmp_index;')

    @skipIf(connection.vendor == 'sqlite',
            'SQLite does not support column drop, '
            'making it hard to test this.')
    def test_raw_alter(self):
        with self.assertNumQueries(1):
            self.assertListEqual(list(Test.objects.all()), [])

        try:
            with self.assertNumQueries(1):
                with connection.cursor() as cursor:
                    cursor.execute(
                        'ALTER TABLE cachalot_test ADD COLUMN tmp INTEGER;')

            with self.assertNumQueries(1):
                self.assertListEqual(list(Test.objects.all()), [])
        finally:
            with connection.cursor() as cursor:
                cursor.execute('ALTER TABLE cachalot_test DROP COLUMN tmp;')

    @skipUnless(
        connection.vendor == 'postgresql',
        'SQLite & MySQL do not revert schema changes in a transaction, '
        'making it hard to test this.')
    @transaction.atomic
    def test_raw_drop(self):
        with self.assertNumQueries(1):
            self.assertListEqual(list(Test.objects.all()), [])

        with self.assertNumQueries(1):
            with connection.cursor() as cursor:
                cursor.execute('DROP TABLE cachalot_test;')

        # The table no longer exists, so an error should be raised
        # after querying it.
        with self.assertRaises((ProgrammingError, OperationalError)):
            with self.assertNumQueries(1):
                self.assertListEqual(list(Test.objects.all()), [])


class DatabaseCommandTestCase(TestUtilsMixin, TransactionTestCase):
    def setUp(self):
        self.t = Test.objects.create(name='test1')

    def test_flush(self):
        with self.assertNumQueries(1):
            self.assertListEqual(list(Test.objects.all()), [self.t])

        call_command('flush', verbosity=0, interactive=False)

        self.force_repoen_connection()

        with self.assertNumQueries(1):
            self.assertListEqual(list(Test.objects.all()), [])

    def test_loaddata(self):
        with self.assertNumQueries(1):
            self.assertListEqual(list(Test.objects.all()), [self.t])

        call_command('loaddata', 'cachalot/tests/loaddata_fixture.json',
                     verbosity=0)

        self.force_repoen_connection()

        with self.assertNumQueries(1):
            self.assertListEqual([t.name for t in Test.objects.all()],
                                 ['test1', 'test2'])