parts/django/tests/regressiontests/aggregation_regress/tests.py
changeset 307 c6bca38c1cbf
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/tests/regressiontests/aggregation_regress/tests.py	Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,757 @@
+import datetime
+import pickle
+from decimal import Decimal
+from operator import attrgetter
+
+from django.conf import settings
+from django.core.exceptions import FieldError
+from django.db import DEFAULT_DB_ALIAS
+from django.db.models import Count, Max, Avg, Sum, StdDev, Variance, F
+from django.test import TestCase, Approximate
+
+from models import Author, Book, Publisher, Clues, Entries, HardbackBook
+
+
+def run_stddev_tests():
+    """Check to see if StdDev/Variance tests should be run.
+
+    Stddev and Variance are not guaranteed to be available for SQLite, and
+    are not available for PostgreSQL before 8.2.
+    """
+    if settings.DATABASES[DEFAULT_DB_ALIAS]['ENGINE'] == 'django.db.backends.sqlite3':
+        return False
+
+    class StdDevPop(object):
+        sql_function = 'STDDEV_POP'
+
+    try:
+        connection.ops.check_aggregate_support(StdDevPop())
+    except:
+        return False
+    return True
+
+
+class AggregationTests(TestCase):
+    def assertObjectAttrs(self, obj, **kwargs):
+        for attr, value in kwargs.iteritems():
+            self.assertEqual(getattr(obj, attr), value)
+
+    def test_aggregates_in_where_clause(self):
+        """
+        Regression test for #12822: DatabaseError: aggregates not allowed in
+        WHERE clause
+
+        Tests that the subselect works and returns results equivalent to a
+        query with the IDs listed.
+
+        Before the corresponding fix for this bug, this test passed in 1.1 and
+        failed in 1.2-beta (trunk).
+        """
+        qs = Book.objects.values('contact').annotate(Max('id'))
+        qs = qs.order_by('contact').values_list('id__max', flat=True)
+        # don't do anything with the queryset (qs) before including it as a
+        # subquery
+        books = Book.objects.order_by('id')
+        qs1 = books.filter(id__in=qs)
+        qs2 = books.filter(id__in=list(qs))
+        self.assertEqual(list(qs1), list(qs2))
+
+    def test_aggregates_in_where_clause_pre_eval(self):
+        """
+        Regression test for #12822: DatabaseError: aggregates not allowed in
+        WHERE clause
+
+        Same as the above test, but evaluates the queryset for the subquery
+        before it's used as a subquery.
+
+        Before the corresponding fix for this bug, this test failed in both
+        1.1 and 1.2-beta (trunk).
+        """
+        qs = Book.objects.values('contact').annotate(Max('id'))
+        qs = qs.order_by('contact').values_list('id__max', flat=True)
+        # force the queryset (qs) for the subquery to be evaluated in its
+        # current state
+        list(qs)
+        books = Book.objects.order_by('id')
+        qs1 = books.filter(id__in=qs)
+        qs2 = books.filter(id__in=list(qs))
+        self.assertEqual(list(qs1), list(qs2))
+
+    if settings.DATABASES[DEFAULT_DB_ALIAS]['ENGINE'] != 'django.db.backends.oracle':
+        def test_annotate_with_extra(self):
+            """
+            Regression test for #11916: Extra params + aggregation creates
+            incorrect SQL.
+            """
+            #oracle doesn't support subqueries in group by clause
+            shortest_book_sql = """
+            SELECT name
+            FROM aggregation_regress_book b
+            WHERE b.publisher_id = aggregation_regress_publisher.id
+            ORDER BY b.pages
+            LIMIT 1
+            """
+            # tests that this query does not raise a DatabaseError due to the full
+            # subselect being (erroneously) added to the GROUP BY parameters
+            qs = Publisher.objects.extra(select={
+                'name_of_shortest_book': shortest_book_sql,
+            }).annotate(total_books=Count('book'))
+            # force execution of the query
+            list(qs)
+
+    def test_aggregate(self):
+        # Ordering requests are ignored
+        self.assertEqual(
+            Author.objects.order_by("name").aggregate(Avg("age")),
+            {"age__avg": Approximate(37.444, places=1)}
+        )
+
+        # Implicit ordering is also ignored
+        self.assertEqual(
+            Book.objects.aggregate(Sum("pages")),
+            {"pages__sum": 3703},
+        )
+
+        # Baseline results
+        self.assertEqual(
+            Book.objects.aggregate(Sum('pages'), Avg('pages')),
+            {'pages__sum': 3703, 'pages__avg': Approximate(617.166, places=2)}
+        )
+
+        # Empty values query doesn't affect grouping or results
+        self.assertEqual(
+            Book.objects.values().aggregate(Sum('pages'), Avg('pages')),
+            {'pages__sum': 3703, 'pages__avg': Approximate(617.166, places=2)}
+        )
+
+        # Aggregate overrides extra selected column
+        self.assertEqual(
+            Book.objects.extra(select={'price_per_page' : 'price / pages'}).aggregate(Sum('pages')),
+            {'pages__sum': 3703}
+        )
+
+    def test_annotation(self):
+        # Annotations get combined with extra select clauses
+        obj = Book.objects.annotate(mean_auth_age=Avg("authors__age")).extra(select={"manufacture_cost": "price * .5"}).get(pk=2)
+        self.assertObjectAttrs(obj,
+            contact_id=3,
+            id=2,
+            isbn=u'067232959',
+            mean_auth_age=45.0,
+            name='Sams Teach Yourself Django in 24 Hours',
+            pages=528,
+            price=Decimal("23.09"),
+            pubdate=datetime.date(2008, 3, 3),
+            publisher_id=2,
+            rating=3.0
+        )
+        # Different DB backends return different types for the extra select computation
+        self.assertTrue(obj.manufacture_cost == 11.545 or obj.manufacture_cost == Decimal('11.545'))
+
+        # Order of the annotate/extra in the query doesn't matter
+        obj = Book.objects.extra(select={'manufacture_cost' : 'price * .5'}).annotate(mean_auth_age=Avg('authors__age')).get(pk=2)
+        self.assertObjectAttrs(obj,
+            contact_id=3,
+            id=2,
+            isbn=u'067232959',
+            mean_auth_age=45.0,
+            name=u'Sams Teach Yourself Django in 24 Hours',
+            pages=528,
+            price=Decimal("23.09"),
+            pubdate=datetime.date(2008, 3, 3),
+            publisher_id=2,
+            rating=3.0
+        )
+        # Different DB backends return different types for the extra select computation
+        self.assertTrue(obj.manufacture_cost == 11.545 or obj.manufacture_cost == Decimal('11.545'))
+
+        # Values queries can be combined with annotate and extra
+        obj = Book.objects.annotate(mean_auth_age=Avg('authors__age')).extra(select={'manufacture_cost' : 'price * .5'}).values().get(pk=2)
+        manufacture_cost = obj['manufacture_cost']
+        self.assertTrue(manufacture_cost == 11.545 or manufacture_cost == Decimal('11.545'))
+        del obj['manufacture_cost']
+        self.assertEqual(obj, {
+            "contact_id": 3,
+            "id": 2,
+            "isbn": u"067232959",
+            "mean_auth_age": 45.0,
+            "name": u"Sams Teach Yourself Django in 24 Hours",
+            "pages": 528,
+            "price": Decimal("23.09"),
+            "pubdate": datetime.date(2008, 3, 3),
+            "publisher_id": 2,
+            "rating": 3.0,
+        })
+
+        # The order of the (empty) values, annotate and extra clauses doesn't
+        # matter
+        obj = Book.objects.values().annotate(mean_auth_age=Avg('authors__age')).extra(select={'manufacture_cost' : 'price * .5'}).get(pk=2)
+        manufacture_cost = obj['manufacture_cost']
+        self.assertTrue(manufacture_cost == 11.545 or manufacture_cost == Decimal('11.545'))
+        del obj['manufacture_cost']
+        self.assertEqual(obj, {
+            'contact_id': 3,
+            'id': 2,
+            'isbn': u'067232959',
+            'mean_auth_age': 45.0,
+            'name': u'Sams Teach Yourself Django in 24 Hours',
+            'pages': 528,
+            'price': Decimal("23.09"),
+            'pubdate': datetime.date(2008, 3, 3),
+            'publisher_id': 2,
+            'rating': 3.0
+        })
+
+        # If the annotation precedes the values clause, it won't be included
+        # unless it is explicitly named
+        obj = Book.objects.annotate(mean_auth_age=Avg('authors__age')).extra(select={'price_per_page' : 'price / pages'}).values('name').get(pk=1)
+        self.assertEqual(obj, {
+            "name": u'The Definitive Guide to Django: Web Development Done Right',
+        })
+
+        obj = Book.objects.annotate(mean_auth_age=Avg('authors__age')).extra(select={'price_per_page' : 'price / pages'}).values('name','mean_auth_age').get(pk=1)
+        self.assertEqual(obj, {
+            'mean_auth_age': 34.5,
+            'name': u'The Definitive Guide to Django: Web Development Done Right',
+        })
+
+        # If an annotation isn't included in the values, it can still be used
+        # in a filter
+        qs = Book.objects.annotate(n_authors=Count('authors')).values('name').filter(n_authors__gt=2)
+        self.assertQuerysetEqual(
+            qs, [
+                {"name": u'Python Web Development with Django'}
+            ],
+            lambda b: b,
+        )
+
+        # The annotations are added to values output if values() precedes
+        # annotate()
+        obj = Book.objects.values('name').annotate(mean_auth_age=Avg('authors__age')).extra(select={'price_per_page' : 'price / pages'}).get(pk=1)
+        self.assertEqual(obj, {
+            'mean_auth_age': 34.5,
+            'name': u'The Definitive Guide to Django: Web Development Done Right',
+        })
+
+        # Check that all of the objects are getting counted (allow_nulls) and
+        # that values respects the amount of objects
+        self.assertEqual(
+            len(Author.objects.annotate(Avg('friends__age')).values()),
+            9
+        )
+
+        # Check that consecutive calls to annotate accumulate in the query
+        qs = Book.objects.values('price').annotate(oldest=Max('authors__age')).order_by('oldest', 'price').annotate(Max('publisher__num_awards'))
+        self.assertQuerysetEqual(
+            qs, [
+                {'price': Decimal("30"), 'oldest': 35, 'publisher__num_awards__max': 3},
+                {'price': Decimal("29.69"), 'oldest': 37, 'publisher__num_awards__max': 7},
+                {'price': Decimal("23.09"), 'oldest': 45, 'publisher__num_awards__max': 1},
+                {'price': Decimal("75"), 'oldest': 57, 'publisher__num_awards__max': 9},
+                {'price': Decimal("82.8"), 'oldest': 57, 'publisher__num_awards__max': 7}
+            ],
+            lambda b: b,
+        )
+
+    def test_aggrate_annotation(self):
+        # Aggregates can be composed over annotations.
+        # The return type is derived from the composed aggregate
+        vals = Book.objects.all().annotate(num_authors=Count('authors__id')).aggregate(Max('pages'), Max('price'), Sum('num_authors'), Avg('num_authors'))
+        self.assertEqual(vals, {
+            'num_authors__sum': 10,
+            'num_authors__avg': Approximate(1.666, places=2),
+            'pages__max': 1132,
+            'price__max': Decimal("82.80")
+        })
+
+    def test_field_error(self):
+        # Bad field requests in aggregates are caught and reported
+        self.assertRaises(
+            FieldError,
+            lambda: Book.objects.all().aggregate(num_authors=Count('foo'))
+        )
+
+        self.assertRaises(
+            FieldError,
+            lambda: Book.objects.all().annotate(num_authors=Count('foo'))
+        )
+
+        self.assertRaises(
+            FieldError,
+            lambda: Book.objects.all().annotate(num_authors=Count('authors__id')).aggregate(Max('foo'))
+        )
+
+    def test_more(self):
+        # Old-style count aggregations can be mixed with new-style
+        self.assertEqual(
+            Book.objects.annotate(num_authors=Count('authors')).count(),
+            6
+        )
+
+        # Non-ordinal, non-computed Aggregates over annotations correctly
+        # inherit the annotation's internal type if the annotation is ordinal
+        # or computed
+        vals = Book.objects.annotate(num_authors=Count('authors')).aggregate(Max('num_authors'))
+        self.assertEqual(
+            vals,
+            {'num_authors__max': 3}
+        )
+
+        vals = Publisher.objects.annotate(avg_price=Avg('book__price')).aggregate(Max('avg_price'))
+        self.assertEqual(
+            vals,
+            {'avg_price__max': 75.0}
+        )
+
+        # Aliases are quoted to protected aliases that might be reserved names
+        vals = Book.objects.aggregate(number=Max('pages'), select=Max('pages'))
+        self.assertEqual(
+            vals,
+            {'number': 1132, 'select': 1132}
+        )
+
+        # Regression for #10064: select_related() plays nice with aggregates
+        obj = Book.objects.select_related('publisher').annotate(num_authors=Count('authors')).values()[0]
+        self.assertEqual(obj, {
+            'contact_id': 8,
+            'id': 5,
+            'isbn': u'013790395',
+            'name': u'Artificial Intelligence: A Modern Approach',
+            'num_authors': 2,
+            'pages': 1132,
+            'price': Decimal("82.8"),
+            'pubdate': datetime.date(1995, 1, 15),
+            'publisher_id': 3,
+            'rating': 4.0,
+        })
+
+        # Regression for #10010: exclude on an aggregate field is correctly
+        # negated
+        self.assertEqual(
+            len(Book.objects.annotate(num_authors=Count('authors'))),
+            6
+        )
+        self.assertEqual(
+            len(Book.objects.annotate(num_authors=Count('authors')).filter(num_authors__gt=2)),
+            1
+        )
+        self.assertEqual(
+            len(Book.objects.annotate(num_authors=Count('authors')).exclude(num_authors__gt=2)),
+            5
+        )
+
+        self.assertEqual(
+            len(Book.objects.annotate(num_authors=Count('authors')).filter(num_authors__lt=3).exclude(num_authors__lt=2)),
+            2
+        )
+        self.assertEqual(
+            len(Book.objects.annotate(num_authors=Count('authors')).exclude(num_authors__lt=2).filter(num_authors__lt=3)),
+            2
+        )
+
+    def test_aggregate_fexpr(self):
+        # Aggregates can be used with F() expressions
+        # ... where the F() is pushed into the HAVING clause
+        qs = Publisher.objects.annotate(num_books=Count('book')).filter(num_books__lt=F('num_awards')/2).order_by('name').values('name','num_books','num_awards')
+        self.assertQuerysetEqual(
+            qs, [
+                {'num_books': 1, 'name': u'Morgan Kaufmann', 'num_awards': 9},
+                {'num_books': 2, 'name': u'Prentice Hall', 'num_awards': 7}
+            ],
+            lambda p: p,
+        )
+
+        qs = Publisher.objects.annotate(num_books=Count('book')).exclude(num_books__lt=F('num_awards')/2).order_by('name').values('name','num_books','num_awards')
+        self.assertQuerysetEqual(
+            qs, [
+                {'num_books': 2, 'name': u'Apress', 'num_awards': 3},
+                {'num_books': 0, 'name': u"Jonno's House of Books", 'num_awards': 0},
+                {'num_books': 1, 'name': u'Sams', 'num_awards': 1}
+            ],
+            lambda p: p,
+        )
+
+        # ... and where the F() references an aggregate
+        qs = Publisher.objects.annotate(num_books=Count('book')).filter(num_awards__gt=2*F('num_books')).order_by('name').values('name','num_books','num_awards')
+        self.assertQuerysetEqual(
+            qs, [
+                {'num_books': 1, 'name': u'Morgan Kaufmann', 'num_awards': 9},
+                {'num_books': 2, 'name': u'Prentice Hall', 'num_awards': 7}
+            ],
+            lambda p: p,
+        )
+
+        qs = Publisher.objects.annotate(num_books=Count('book')).exclude(num_books__lt=F('num_awards')/2).order_by('name').values('name','num_books','num_awards')
+        self.assertQuerysetEqual(
+            qs, [
+                {'num_books': 2, 'name': u'Apress', 'num_awards': 3},
+                {'num_books': 0, 'name': u"Jonno's House of Books", 'num_awards': 0},
+                {'num_books': 1, 'name': u'Sams', 'num_awards': 1}
+            ],
+            lambda p: p,
+        )
+
+    def test_db_col_table(self):
+        # Tests on fields with non-default table and column names.
+        qs = Clues.objects.values('EntryID__Entry').annotate(Appearances=Count('EntryID'), Distinct_Clues=Count('Clue', distinct=True))
+        self.assertQuerysetEqual(qs, [])
+
+        qs = Entries.objects.annotate(clue_count=Count('clues__ID'))
+        self.assertQuerysetEqual(qs, [])
+
+    def test_empty(self):
+        # Regression for #10089: Check handling of empty result sets with
+        # aggregates
+        self.assertEqual(
+            Book.objects.filter(id__in=[]).count(),
+            0
+        )
+
+        vals = Book.objects.filter(id__in=[]).aggregate(num_authors=Count('authors'), avg_authors=Avg('authors'), max_authors=Max('authors'), max_price=Max('price'), max_rating=Max('rating'))
+        self.assertEqual(
+            vals,
+            {'max_authors': None, 'max_rating': None, 'num_authors': 0, 'avg_authors': None, 'max_price': None}
+        )
+
+        qs = Publisher.objects.filter(pk=5).annotate(num_authors=Count('book__authors'), avg_authors=Avg('book__authors'), max_authors=Max('book__authors'), max_price=Max('book__price'), max_rating=Max('book__rating')).values()
+        self.assertQuerysetEqual(
+            qs, [
+                {'max_authors': None, 'name': u"Jonno's House of Books", 'num_awards': 0, 'max_price': None, 'num_authors': 0, 'max_rating': None, 'id': 5, 'avg_authors': None}
+            ],
+            lambda p: p
+        )
+
+    def test_more_more(self):
+        # Regression for #10113 - Fields mentioned in order_by() must be
+        # included in the GROUP BY. This only becomes a problem when the
+        # order_by introduces a new join.
+        self.assertQuerysetEqual(
+            Book.objects.annotate(num_authors=Count('authors')).order_by('publisher__name', 'name'), [
+                "Practical Django Projects",
+                "The Definitive Guide to Django: Web Development Done Right",
+                "Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp",
+                "Artificial Intelligence: A Modern Approach",
+                "Python Web Development with Django",
+                "Sams Teach Yourself Django in 24 Hours",
+            ],
+            lambda b: b.name
+        )
+
+        # Regression for #10127 - Empty select_related() works with annotate
+        qs = Book.objects.filter(rating__lt=4.5).select_related().annotate(Avg('authors__age'))
+        self.assertQuerysetEqual(
+            qs, [
+                (u'Artificial Intelligence: A Modern Approach', 51.5, u'Prentice Hall', u'Peter Norvig'),
+                (u'Practical Django Projects', 29.0, u'Apress', u'James Bennett'),
+                (u'Python Web Development with Django', Approximate(30.333, places=2), u'Prentice Hall', u'Jeffrey Forcier'),
+                (u'Sams Teach Yourself Django in 24 Hours', 45.0, u'Sams', u'Brad Dayley')
+            ],
+            lambda b: (b.name, b.authors__age__avg, b.publisher.name, b.contact.name)
+        )
+
+        # Regression for #10132 - If the values() clause only mentioned extra
+        # (select=) columns, those columns are used for grouping
+        qs = Book.objects.extra(select={'pub':'publisher_id'}).values('pub').annotate(Count('id')).order_by('pub')
+        self.assertQuerysetEqual(
+            qs, [
+                {'pub': 1, 'id__count': 2},
+                {'pub': 2, 'id__count': 1},
+                {'pub': 3, 'id__count': 2},
+                {'pub': 4, 'id__count': 1}
+            ],
+            lambda b: b
+        )
+
+        qs = Book.objects.extra(select={'pub':'publisher_id', 'foo':'pages'}).values('pub').annotate(Count('id')).order_by('pub')
+        self.assertQuerysetEqual(
+            qs, [
+                {'pub': 1, 'id__count': 2},
+                {'pub': 2, 'id__count': 1},
+                {'pub': 3, 'id__count': 2},
+                {'pub': 4, 'id__count': 1}
+            ],
+            lambda b: b
+        )
+
+        # Regression for #10182 - Queries with aggregate calls are correctly
+        # realiased when used in a subquery
+        ids = Book.objects.filter(pages__gt=100).annotate(n_authors=Count('authors')).filter(n_authors__gt=2).order_by('n_authors')
+        self.assertQuerysetEqual(
+            Book.objects.filter(id__in=ids), [
+                "Python Web Development with Django",
+            ],
+            lambda b: b.name
+        )
+
+    def test_duplicate_alias(self):
+        # Regression for #11256 - duplicating a default alias raises ValueError.
+        self.assertRaises(ValueError, Book.objects.all().annotate, Avg('authors__age'), authors__age__avg=Avg('authors__age'))
+
+    def test_field_name_conflict(self):
+        # Regression for #11256 - providing an aggregate name that conflicts with a field name on the model raises ValueError
+        self.assertRaises(ValueError, Author.objects.annotate, age=Avg('friends__age'))
+
+    def test_m2m_name_conflict(self):
+        # Regression for #11256 - providing an aggregate name that conflicts with an m2m name on the model raises ValueError
+        self.assertRaises(ValueError, Author.objects.annotate, friends=Count('friends'))
+
+    def test_reverse_relation_name_conflict(self):
+        # Regression for #11256 - providing an aggregate name that conflicts with a reverse-related name on the model raises ValueError
+        self.assertRaises(ValueError, Author.objects.annotate, book_contact_set=Avg('friends__age'))
+
+    def test_pickle(self):
+        # Regression for #10197 -- Queries with aggregates can be pickled.
+        # First check that pickling is possible at all. No crash = success
+        qs = Book.objects.annotate(num_authors=Count('authors'))
+        pickle.dumps(qs)
+
+        # Then check that the round trip works.
+        query = qs.query.get_compiler(qs.db).as_sql()[0]
+        qs2 = pickle.loads(pickle.dumps(qs))
+        self.assertEqual(
+            qs2.query.get_compiler(qs2.db).as_sql()[0],
+            query,
+        )
+
+    def test_more_more_more(self):
+        # Regression for #10199 - Aggregate calls clone the original query so
+        # the original query can still be used
+        books = Book.objects.all()
+        books.aggregate(Avg("authors__age"))
+        self.assertQuerysetEqual(
+            books.all(), [
+                u'Artificial Intelligence: A Modern Approach',
+                u'Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp',
+                u'Practical Django Projects',
+                u'Python Web Development with Django',
+                u'Sams Teach Yourself Django in 24 Hours',
+                u'The Definitive Guide to Django: Web Development Done Right'
+            ],
+            lambda b: b.name
+        )
+
+        # Regression for #10248 - Annotations work with DateQuerySets
+        qs = Book.objects.annotate(num_authors=Count('authors')).filter(num_authors=2).dates('pubdate', 'day')
+        self.assertQuerysetEqual(
+            qs, [
+                datetime.datetime(1995, 1, 15, 0, 0),
+                datetime.datetime(2007, 12, 6, 0, 0)
+            ],
+            lambda b: b
+        )
+
+        # Regression for #10290 - extra selects with parameters can be used for
+        # grouping.
+        qs = Book.objects.annotate(mean_auth_age=Avg('authors__age')).extra(select={'sheets' : '(pages + %s) / %s'}, select_params=[1, 2]).order_by('sheets').values('sheets')
+        self.assertQuerysetEqual(
+            qs, [
+                150,
+                175,
+                224,
+                264,
+                473,
+                566
+            ],
+            lambda b: int(b["sheets"])
+        )
+
+        # Regression for 10425 - annotations don't get in the way of a count()
+        # clause
+        self.assertEqual(
+            Book.objects.values('publisher').annotate(Count('publisher')).count(),
+            4
+        )
+        self.assertEqual(
+            Book.objects.annotate(Count('publisher')).values('publisher').count(),
+            6
+        )
+
+        publishers = Publisher.objects.filter(id__in=[1, 2])
+        self.assertQuerysetEqual(
+            publishers, [
+                "Apress",
+                "Sams"
+            ],
+            lambda p: p.name
+        )
+
+        publishers = publishers.annotate(n_books=Count("book"))
+        self.assertEqual(
+            publishers[0].n_books,
+            2
+        )
+
+        self.assertQuerysetEqual(
+            publishers, [
+                "Apress",
+                "Sams",
+            ],
+            lambda p: p.name
+        )
+
+        books = Book.objects.filter(publisher__in=publishers)
+        self.assertQuerysetEqual(
+            books, [
+                "Practical Django Projects",
+                "Sams Teach Yourself Django in 24 Hours",
+                "The Definitive Guide to Django: Web Development Done Right",
+            ],
+            lambda b: b.name
+        )
+        self.assertQuerysetEqual(
+            publishers, [
+                "Apress",
+                "Sams",
+            ],
+            lambda p: p.name
+        )
+
+        # Regression for 10666 - inherited fields work with annotations and
+        # aggregations
+        self.assertEqual(
+            HardbackBook.objects.aggregate(n_pages=Sum('book_ptr__pages')),
+            {'n_pages': 2078}
+        )
+
+        self.assertEqual(
+            HardbackBook.objects.aggregate(n_pages=Sum('pages')),
+            {'n_pages': 2078},
+        )
+
+        qs = HardbackBook.objects.annotate(n_authors=Count('book_ptr__authors')).values('name', 'n_authors')
+        self.assertQuerysetEqual(
+            qs, [
+                {'n_authors': 2, 'name': u'Artificial Intelligence: A Modern Approach'},
+                {'n_authors': 1, 'name': u'Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp'}
+            ],
+            lambda h: h
+        )
+
+        qs = HardbackBook.objects.annotate(n_authors=Count('authors')).values('name', 'n_authors')
+        self.assertQuerysetEqual(
+            qs, [
+                {'n_authors': 2, 'name': u'Artificial Intelligence: A Modern Approach'},
+                {'n_authors': 1, 'name': u'Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp'}
+            ],
+            lambda h: h,
+        )
+
+        # Regression for #10766 - Shouldn't be able to reference an aggregate
+        # fields in an an aggregate() call.
+        self.assertRaises(
+            FieldError,
+            lambda: Book.objects.annotate(mean_age=Avg('authors__age')).annotate(Avg('mean_age'))
+        )
+
+    def test_empty_filter_count(self):
+        self.assertEqual(
+            Author.objects.filter(id__in=[]).annotate(Count("friends")).count(),
+            0
+        )
+
+    def test_empty_filter_aggregate(self):
+        self.assertEqual(
+            Author.objects.filter(id__in=[]).annotate(Count("friends")).aggregate(Count("pk")),
+            {"pk__count": None}
+        )
+
+    def test_annotate_and_join(self):
+        self.assertEqual(
+            Author.objects.annotate(c=Count("friends__name")).exclude(friends__name="Joe").count(),
+            Author.objects.count()
+        )
+
+    def test_f_expression_annotation(self):
+        # Books with less than 200 pages per author.
+        qs = Book.objects.values("name").annotate(
+            n_authors=Count("authors")
+        ).filter(
+            pages__lt=F("n_authors") * 200
+        ).values_list("pk")
+        self.assertQuerysetEqual(
+            Book.objects.filter(pk__in=qs), [
+                "Python Web Development with Django"
+            ],
+            attrgetter("name")
+        )
+
+    def test_values_annotate_values(self):
+        qs = Book.objects.values("name").annotate(
+            n_authors=Count("authors")
+        ).values_list("pk", flat=True)
+        self.assertEqual(list(qs), list(Book.objects.values_list("pk", flat=True)))
+
+    def test_having_group_by(self):
+        # Test that when a field occurs on the LHS of a HAVING clause that it
+        # appears correctly in the GROUP BY clause
+        qs = Book.objects.values_list("name").annotate(
+            n_authors=Count("authors")
+        ).filter(
+            pages__gt=F("n_authors")
+        ).values_list("name", flat=True)
+        # Results should be the same, all Books have more pages than authors
+        self.assertEqual(
+            list(qs), list(Book.objects.values_list("name", flat=True))
+        )
+
+    if run_stddev_tests():
+        def test_stddev(self):
+            self.assertEqual(
+                Book.objects.aggregate(StdDev('pages')),
+                {'pages__stddev': Approximate(311.46, 1)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(StdDev('rating')),
+                {'rating__stddev': Approximate(0.60, 1)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(StdDev('price')),
+                {'price__stddev': Approximate(24.16, 2)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(StdDev('pages', sample=True)),
+                {'pages__stddev': Approximate(341.19, 2)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(StdDev('rating', sample=True)),
+                {'rating__stddev': Approximate(0.66, 2)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(StdDev('price', sample=True)),
+                {'price__stddev': Approximate(26.46, 1)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(Variance('pages')),
+                {'pages__variance': Approximate(97010.80, 1)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(Variance('rating')),
+                {'rating__variance': Approximate(0.36, 1)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(Variance('price')),
+                {'price__variance': Approximate(583.77, 1)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(Variance('pages', sample=True)),
+                {'pages__variance': Approximate(116412.96, 1)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(Variance('rating', sample=True)),
+                {'rating__variance': Approximate(0.44, 2)}
+            )
+
+            self.assertEqual(
+                Book.objects.aggregate(Variance('price', sample=True)),
+                {'price__variance': Approximate(700.53, 2)}
+            )