Python django.test.utils.CaptureQueriesContext() Examples

def test_for_update_sql_generated_of(self):
        """
        The backend's FOR UPDATE OF variant appears in the generated SQL when
        select_for_update() is invoked.
        """
        with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
            list(Person.objects.select_related(
                'born__country',
            ).select_for_update(
                of=('born__country',),
            ).select_for_update(
                of=('self', 'born__country')
            ))
        features = connections['default'].features
        if features.select_for_update_of_column:
            expected = ['select_for_update_person"."id', 'select_for_update_country"."id']
        else:
            expected = ['select_for_update_person', 'select_for_update_country']
        expected = [connection.ops.quote_name(value) for value in expected]
        self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected)) 

def test_for_update_sql_generated_of(self):
        """
        The backend's FOR UPDATE OF variant appears in the generated SQL when
        select_for_update() is invoked.
        """
        with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
            list(Person.objects.select_related(
                'born__country',
            ).select_for_update(
                of=('born__country',),
            ).select_for_update(
                of=('self', 'born__country')
            ))
        features = connections['default'].features
        if features.select_for_update_of_column:
            expected = ['"select_for_update_person"."id"', '"select_for_update_country"."id"']
        else:
            expected = ['"select_for_update_person"', '"select_for_update_country"']
        if features.uppercases_column_names:
            expected = [value.upper() for value in expected]
        self.assertTrue(self.has_for_update_sql(ctx.captured_queries, of=expected)) 

def test_update_parent_filtering(self):
        """
        Updating a field of a model subclass doesn't issue an UPDATE
        query constrained by an inner query (#10399).
        """
        supplier = Supplier.objects.create(
            name='Central market',
            address='610 some street',
        )
        # Capture the expected query in a database agnostic way
        with CaptureQueriesContext(connection) as captured_queries:
            Place.objects.filter(pk=supplier.pk).update(name=supplier.name)
        expected_sql = captured_queries[0]['sql']
        # Capture the queries executed when a subclassed model instance is saved.
        with CaptureQueriesContext(connection) as captured_queries:
            supplier.save(update_fields=('name',))
        for query in captured_queries:
            sql = query['sql']
            if 'UPDATE' in sql:
                self.assertEqual(expected_sql, sql) 

def test_postgres_options(self):
        qs = Tag.objects.filter(name='test')
        test_options = [
            {'COSTS': False, 'BUFFERS': True, 'ANALYZE': True},
            {'costs': False, 'buffers': True, 'analyze': True},
            {'verbose': True, 'timing': True, 'analyze': True},
            {'verbose': False, 'timing': False, 'analyze': True},
        ]
        if connection.pg_version >= 100000:
            test_options.append({'summary': True})
        for options in test_options:
            with self.subTest(**options), transaction.atomic():
                with CaptureQueriesContext(connection) as captured_queries:
                    qs.explain(format='text', **options)
                self.assertEqual(len(captured_queries), 1)
                for name, value in options.items():
                    option = '{} {}'.format(name.upper(), 'true' if value else 'false')
                    self.assertIn(option, captured_queries[0]['sql']) 

def test_basic(self):
        querysets = [
            Tag.objects.filter(name='test'),
            Tag.objects.filter(name='test').select_related('parent'),
            Tag.objects.filter(name='test').prefetch_related('children'),
            Tag.objects.filter(name='test').annotate(Count('children')),
            Tag.objects.filter(name='test').values_list('name'),
            Tag.objects.order_by().union(Tag.objects.order_by().filter(name='test')),
            Tag.objects.all().select_for_update().filter(name='test'),
        ]
        supported_formats = connection.features.supported_explain_formats
        all_formats = (None,) + tuple(supported_formats) + tuple(f.lower() for f in supported_formats)
        for idx, queryset in enumerate(querysets):
            for format in all_formats:
                with self.subTest(format=format, queryset=idx):
                    if connection.vendor == 'mysql':
                        # This does a query and caches the result.
                        connection.features.needs_explain_extended
                    with self.assertNumQueries(1), CaptureQueriesContext(connection) as captured_queries:
                        result = queryset.explain(format=format)
                        self.assertTrue(captured_queries[0]['sql'].startswith(connection.ops.explain_prefix))
                        self.assertIsInstance(result, str)
                        self.assertTrue(result) 

def test_postgres_options(self):
        qs = Tag.objects.filter(name='test')
        test_options = [
            {'COSTS': False, 'BUFFERS': True, 'ANALYZE': True},
            {'costs': False, 'buffers': True, 'analyze': True},
            {'verbose': True, 'timing': True, 'analyze': True},
            {'verbose': False, 'timing': False, 'analyze': True},
        ]
        if connection.pg_version >= 100000:
            test_options.append({'summary': True})
        for options in test_options:
            with self.subTest(**options), transaction.atomic():
                with CaptureQueriesContext(connection) as captured_queries:
                    qs.explain(format='text', **options)
                self.assertEqual(len(captured_queries), 1)
                for name, value in options.items():
                    option = '{} {}'.format(name.upper(), 'true' if value else 'false')
                    self.assertIn(option, captured_queries[0]['sql']) 

def test_basic(self):
        querysets = [
            Tag.objects.filter(name='test'),
            Tag.objects.filter(name='test').select_related('parent'),
            Tag.objects.filter(name='test').prefetch_related('children'),
            Tag.objects.filter(name='test').annotate(Count('children')),
            Tag.objects.filter(name='test').values_list('name'),
            Tag.objects.order_by().union(Tag.objects.order_by().filter(name='test')),
            Tag.objects.all().select_for_update().filter(name='test'),
        ]
        supported_formats = connection.features.supported_explain_formats
        all_formats = (None,) + tuple(supported_formats) + tuple(f.lower() for f in supported_formats)
        for idx, queryset in enumerate(querysets):
            for format in all_formats:
                with self.subTest(format=format, queryset=idx):
                    if connection.vendor == 'mysql':
                        # This does a query and caches the result.
                        connection.features.needs_explain_extended
                    with self.assertNumQueries(1), CaptureQueriesContext(connection) as captured_queries:
                        result = queryset.explain(format=format)
                        self.assertTrue(captured_queries[0]['sql'].startswith(connection.ops.explain_prefix))
                        self.assertIsInstance(result, str)
                        self.assertTrue(result) 

def test_add_field(self):
        """
        Tests adding fields to models
        """
        # Create the table
        with connection.schema_editor() as editor:
            editor.create_model(Author)
        # Ensure there's no age field
        columns = self.column_classes(Author)
        self.assertNotIn("age", columns)
        # Add the new field
        new_field = IntegerField(null=True)
        new_field.set_attributes_from_name("age")
        with CaptureQueriesContext(connection) as ctx, connection.schema_editor() as editor:
            editor.add_field(Author, new_field)
        drop_default_sql = editor.sql_alter_column_no_default % {
            'column': editor.quote_name(new_field.name),
        }
        self.assertFalse(any(drop_default_sql in query['sql'] for query in ctx.captured_queries))
        # Ensure the field is right afterwards
        columns = self.column_classes(Author)
        self.assertEqual(columns['age'][0], "IntegerField")
        self.assertEqual(columns['age'][1][6], True) 

def test_ticket11881(self):
        """
        Subqueries do not needlessly contain ORDER BY, SELECT FOR UPDATE or
        select_related() stuff.
        """
        qs = Book.objects.all().select_for_update().order_by(
            'pk').select_related('publisher').annotate(max_pk=Max('pk'))
        with CaptureQueriesContext(connection) as captured_queries:
            qs.aggregate(avg_pk=Avg('max_pk'))
            self.assertEqual(len(captured_queries), 1)
            qstr = captured_queries[0]['sql'].lower()
            self.assertNotIn('for update', qstr)
            forced_ordering = connection.ops.force_no_ordering()
            if forced_ordering:
                # If the backend needs to force an ordering we make sure it's
                # the only "ORDER BY" clause present in the query.
                self.assertEqual(
                    re.findall(r'order by (\w+)', qstr),
                    [', '.join(f[1][0] for f in forced_ordering).lower()]
                )
            else:
                self.assertNotIn('order by', qstr)
            self.assertEqual(qstr.count(' join '), 0) 

def test_add_field(self):
        """
        Tests adding fields to models
        """
        # Create the table
        with connection.schema_editor() as editor:
            editor.create_model(Author)
        # Ensure there's no age field
        columns = self.column_classes(Author)
        self.assertNotIn("age", columns)
        # Add the new field
        new_field = IntegerField(null=True)
        new_field.set_attributes_from_name("age")
        with CaptureQueriesContext(connection) as ctx, connection.schema_editor() as editor:
            editor.add_field(Author, new_field)
        drop_default_sql = editor.sql_alter_column_no_default % {
            'column': editor.quote_name(new_field.name),
        }
        self.assertFalse(any(drop_default_sql in query['sql'] for query in ctx.captured_queries))
        # Ensure the field is right afterwards
        columns = self.column_classes(Author)
        self.assertEqual(columns['age'][0], "IntegerField")
        self.assertEqual(columns['age'][1][6], True) 

def test_running_without_changes(self):
        project_state = self.set_up_test_model("test_arstd")
        operation = AlterStorageEngine("Pony", from_engine="MyISAM", to_engine="InnoDB")

        assert table_storage_engine("test_arstd_pony") == "InnoDB"

        # Forwards - shouldn't actually do an ALTER since it is already InnoDB
        new_state = project_state.clone()
        operation.state_forwards("test_arstd", new_state)
        capturer = CaptureQueriesContext(connection)
        with capturer, connection.schema_editor() as editor:
            operation.database_forwards("test_arstd", editor, project_state, new_state)
        queries = [q["sql"] for q in capturer.captured_queries]
        assert not any(q.startswith("ALTER TABLE ") for q in queries)
        assert table_storage_engine("test_arstd_pony") == "InnoDB"

        # Backwards - will actually ALTER since it is going 'back' to MyISAM
        with connection.schema_editor() as editor:
            operation.database_backwards("test_arstd", editor, new_state, project_state)
        assert table_storage_engine("test_arstd_pony") == "MyISAM"

    # Copied from django core migration tests 

def test_ticket11881(self):
        """
        Subqueries do not needlessly contain ORDER BY, SELECT FOR UPDATE or
        select_related() stuff.
        """
        qs = Book.objects.all().select_for_update().order_by(
            'pk').select_related('publisher').annotate(max_pk=Max('pk'))
        with CaptureQueriesContext(connection) as captured_queries:
            qs.aggregate(avg_pk=Avg('max_pk'))
            self.assertEqual(len(captured_queries), 1)
            qstr = captured_queries[0]['sql'].lower()
            self.assertNotIn('for update', qstr)
            forced_ordering = connection.ops.force_no_ordering()
            if forced_ordering:
                # If the backend needs to force an ordering we make sure it's
                # the only "ORDER BY" clause present in the query.
                self.assertEqual(
                    re.findall(r'order by (\w+)', qstr),
                    [', '.join(f[1][0] for f in forced_ordering).lower()]
                )
            else:
                self.assertNotIn('order by', qstr)
            self.assertEqual(qstr.count(' join '), 0) 

def test_ticket11881(self):
        """
        Subqueries do not needlessly contain ORDER BY, SELECT FOR UPDATE or
        select_related() stuff.
        """
        qs = Book.objects.all().select_for_update().order_by(
            'pk').select_related('publisher').annotate(max_pk=Max('pk'))
        with CaptureQueriesContext(connection) as captured_queries:
            qs.aggregate(avg_pk=Avg('max_pk'))
            self.assertEqual(len(captured_queries), 1)
            qstr = captured_queries[0]['sql'].lower()
            self.assertNotIn('for update', qstr)
            forced_ordering = connection.ops.force_no_ordering()
            if forced_ordering:
                # If the backend needs to force an ordering we make sure it's
                # the only "ORDER BY" clause present in the query.
                self.assertEqual(
                    re.findall(r'order by (\w+)', qstr),
                    [', '.join(f[1][0] for f in forced_ordering).lower()]
                )
            else:
                self.assertNotIn('order by', qstr)
            self.assertEqual(qstr.count(' join '), 0) 

def test_m2m_then_m2m_object_ids(self):
        with CaptureQueriesContext(connection) as queries:
            list(Book.objects.prefetch_related('authors__favorite_authors'))

        sql = queries[-1]['sql']
        self.assertWhereContains(sql, self.author1.name) 

def test_for_update_sql_generated_skip_locked(self):
        """
        The backend's FOR UPDATE SKIP LOCKED variant appears in
        generated SQL when select_for_update is invoked.
        """
        with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
            list(Person.objects.all().select_for_update(skip_locked=True))
        self.assertTrue(self.has_for_update_sql(ctx.captured_queries, skip_locked=True)) 

def test_m2m_then_reverse_fk_object_ids(self):
        with CaptureQueriesContext(connection) as queries:
            list(Book.objects.prefetch_related('authors__addresses'))

        sql = queries[-1]['sql']
        self.assertWhereContains(sql, self.author1.name) 

def test_lhs_with_index_rhs_without_index(self):
        with CaptureQueriesContext(connection) as queries:
            RasterModel.objects.filter(rast__0__contains=json.loads(JSON_RASTER)).exists()
        # It's easier to check the indexes in the generated SQL than to write
        # tests that cover all index combinations.
        self.assertRegex(queries[-1]['sql'], r'WHERE ST_Contains\([^)]*, 1, [^)]*, 1\)') 

def test_m2m_then_reverse_one_to_one_object_ids(self):
        with CaptureQueriesContext(connection) as queries:
            list(Book.objects.prefetch_related('authors__authorwithage'))

        sql = queries[-1]['sql']
        self.assertWhereContains(sql, self.author1.id) 

def test_count_join_optimization(self):
        with CaptureQueriesContext(connection) as query:
            self.article.publications.count()
        self.assertNotIn('JOIN', query[0]['sql'])
        self.assertEqual(self.nullable_target_article.publications.count(), 0) 

def test_count_join_optimization_disabled(self):
        with mock.patch.object(connection.features, 'supports_foreign_keys', False), \
                CaptureQueriesContext(connection) as query:
            self.article.publications.count()
        self.assertIn('JOIN', query[0]['sql']) 

def test_exists_join_optimization(self):
        with CaptureQueriesContext(connection) as query:
            self.article.publications.exists()
        self.assertNotIn('JOIN', query[0]['sql'])
        self.assertIs(self.nullable_target_article.publications.exists(), False) 

def test_exists_join_optimization_disabled(self):
        with mock.patch.object(connection.features, 'supports_foreign_keys', False), \
                CaptureQueriesContext(connection) as query:
            self.article.publications.exists()
        self.assertIn('JOIN', query[0]['sql']) 

def test_exists(self):
        with CaptureQueriesContext(connection) as captured_queries:
            self.assertFalse(Tag.objects.exists())
        # Ok - so the exist query worked - but did it include too many columns?
        self.assertEqual(len(captured_queries), 1)
        qstr = captured_queries[0]['sql']
        id, name = connection.ops.quote_name('id'), connection.ops.quote_name('name')
        self.assertNotIn(id, qstr)
        self.assertNotIn(name, qstr) 

def test_mysql_text_to_traditional(self):
        # Initialize the cached property, if needed, to prevent a query for
        # the MySQL version during the QuerySet evaluation.
        connection.features.needs_explain_extended
        with CaptureQueriesContext(connection) as captured_queries:
            Tag.objects.filter(name='test').explain(format='text')
        self.assertEqual(len(captured_queries), 1)
        self.assertIn('FORMAT=TRADITIONAL', captured_queries[0]['sql']) 

def test_mysql_extended(self):
        # Inner skip to avoid module level query for MySQL version.
        if not connection.features.needs_explain_extended:
            raise unittest.SkipTest('MySQL < 5.7 specific')
        qs = Tag.objects.filter(name='test')
        with CaptureQueriesContext(connection) as captured_queries:
            qs.explain(format='json')
        self.assertEqual(len(captured_queries), 1)
        self.assertNotIn('EXTENDED', captured_queries[0]['sql'])
        with CaptureQueriesContext(connection) as captured_queries:
            qs.explain(format='text')
        self.assertEqual(len(captured_queries), 1)
        self.assertNotIn('EXTENDED', captured_queries[0]['sql']) 

def test_for_update_sql_generated_nowait(self):
        """
        The backend's FOR UPDATE NOWAIT variant appears in
        generated SQL when select_for_update is invoked.
        """
        with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
            list(Person.objects.all().select_for_update(nowait=True))
        self.assertTrue(self.has_for_update_sql(ctx.captured_queries, nowait=True)) 

def test_for_update_sql_generated_skip_locked(self):
        """
        The backend's FOR UPDATE SKIP LOCKED variant appears in
        generated SQL when select_for_update is invoked.
        """
        with transaction.atomic(), CaptureQueriesContext(connection) as ctx:
            list(Person.objects.all().select_for_update(skip_locked=True))
        self.assertTrue(self.has_for_update_sql(ctx.captured_queries, skip_locked=True)) 

def test_makes_no_db_queries(self, client):
        queries = CaptureQueriesContext(connection)
        with queries:
            res = client.get("/api/v1/classify_client/")
            assert res.status_code == 200
        assert len(queries) == 0 

def __enter__(self):
        self.capturer = CaptureQueriesContext(self.conn)
        self.capturer.__enter__()
        return self 

def test_apis_make_a_reasonable_number_of_db_queries(client, endpoint, Factory):
    """
    Naive versions of these views could easily make several queries
    per item, which is very slow. Make sure that isn't the case.
    """
    Factory.create_batch(100)
    queries = CaptureQueriesContext(connection)
    with queries:
        res = client.get(endpoint)
        assert res.status_code == 200
    # Anything under 100 isn't doing one query per recipe.
    assert len(queries) < 100