django/tests/aggregation/tests.py

from __future__ import unicode_literals

import datetime
from decimal import Decimal
import re

from django.db import connection
from django.db.models import Avg, Sum, Count, Max, Min
from django.test import TestCase
from django.test.utils import Approximate
from django.test.utils import CaptureQueriesContext

from .models import Author, Publisher, Book, Store


class BaseAggregateTestCase(TestCase):
    fixtures = ["aggregation.json"]

    def test_empty_aggregate(self):
        self.assertEqual(Author.objects.all().aggregate(), {})

    def test_single_aggregate(self):
        vals = Author.objects.aggregate(Avg("age"))
        self.assertEqual(vals, {"age__avg": Approximate(37.4, places=1)})

    def test_multiple_aggregates(self):
        vals = Author.objects.aggregate(Sum("age"), Avg("age"))
        self.assertEqual(vals, {"age__sum": 337, "age__avg": Approximate(37.4, places=1)})

    def test_filter_aggregate(self):
        vals = Author.objects.filter(age__gt=29).aggregate(Sum("age"))
        self.assertEqual(len(vals), 1)
        self.assertEqual(vals["age__sum"], 254)

    def test_related_aggregate(self):
        vals = Author.objects.aggregate(Avg("friends__age"))
        self.assertEqual(len(vals), 1)
        self.assertAlmostEqual(vals["friends__age__avg"], 34.07, places=2)

        vals = Book.objects.filter(rating__lt=4.5).aggregate(Avg("authors__age"))
        self.assertEqual(len(vals), 1)
        self.assertAlmostEqual(vals["authors__age__avg"], 38.2857, places=2)

        vals = Author.objects.all().filter(name__contains="a").aggregate(Avg("book__rating"))
        self.assertEqual(len(vals), 1)
        self.assertEqual(vals["book__rating__avg"], 4.0)

        vals = Book.objects.aggregate(Sum("publisher__num_awards"))
        self.assertEqual(len(vals), 1)
        self.assertEqual(vals["publisher__num_awards__sum"], 30)

        vals = Publisher.objects.aggregate(Sum("book__price"))
        self.assertEqual(len(vals), 1)
        self.assertEqual(vals["book__price__sum"], Decimal("270.27"))

    def test_aggregate_multi_join(self):
        vals = Store.objects.aggregate(Max("books__authors__age"))
        self.assertEqual(len(vals), 1)
        self.assertEqual(vals["books__authors__age__max"], 57)

        vals = Author.objects.aggregate(Min("book__publisher__num_awards"))
        self.assertEqual(len(vals), 1)
        self.assertEqual(vals["book__publisher__num_awards__min"], 1)

    def test_aggregate_alias(self):
        vals = Store.objects.filter(name="Amazon.com").aggregate(amazon_mean=Avg("books__rating"))
        self.assertEqual(len(vals), 1)
        self.assertAlmostEqual(vals["amazon_mean"], 4.08, places=2)

    def test_annotate_basic(self):
        self.assertQuerysetEqual(
            Book.objects.annotate().order_by('pk'), [
                "The Definitive Guide to Django: Web Development Done Right",
                "Sams Teach Yourself Django in 24 Hours",
                "Practical Django Projects",
                "Python Web Development with Django",
                "Artificial Intelligence: A Modern Approach",
                "Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp"
            ],
            lambda b: b.name
        )

        books = Book.objects.annotate(mean_age=Avg("authors__age"))
        b = books.get(pk=1)
        self.assertEqual(
            b.name,
            'The Definitive Guide to Django: Web Development Done Right'
        )
        self.assertEqual(b.mean_age, 34.5)

    def test_annotate_m2m(self):
        books = Book.objects.filter(rating__lt=4.5).annotate(Avg("authors__age")).order_by("name")
        self.assertQuerysetEqual(
            books, [
                ('Artificial Intelligence: A Modern Approach', 51.5),
                ('Practical Django Projects', 29.0),
                ('Python Web Development with Django', Approximate(30.3, places=1)),
                ('Sams Teach Yourself Django in 24 Hours', 45.0)
            ],
            lambda b: (b.name, b.authors__age__avg),
        )

        books = Book.objects.annotate(num_authors=Count("authors")).order_by("name")
        self.assertQuerysetEqual(
            books, [
                ('Artificial Intelligence: A Modern Approach', 2),
                ('Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp', 1),
                ('Practical Django Projects', 1),
                ('Python Web Development with Django', 3),
                ('Sams Teach Yourself Django in 24 Hours', 1),
                ('The Definitive Guide to Django: Web Development Done Right', 2)
            ],
            lambda b: (b.name, b.num_authors)
        )

    def test_backwards_m2m_annotate(self):
        authors = Author.objects.filter(name__contains="a").annotate(Avg("book__rating")).order_by("name")
        self.assertQuerysetEqual(
            authors, [
                ('Adrian Holovaty', 4.5),
                ('Brad Dayley', 3.0),
                ('Jacob Kaplan-Moss', 4.5),
                ('James Bennett', 4.0),
                ('Paul Bissex', 4.0),
                ('Stuart Russell', 4.0)
            ],
            lambda a: (a.name, a.book__rating__avg)
        )

        authors = Author.objects.annotate(num_books=Count("book")).order_by("name")
        self.assertQuerysetEqual(
            authors, [
                ('Adrian Holovaty', 1),
                ('Brad Dayley', 1),
                ('Jacob Kaplan-Moss', 1),
                ('James Bennett', 1),
                ('Jeffrey Forcier', 1),
                ('Paul Bissex', 1),
                ('Peter Norvig', 2),
                ('Stuart Russell', 1),
                ('Wesley J. Chun', 1)
            ],
            lambda a: (a.name, a.num_books)
        )

    def test_reverse_fkey_annotate(self):
        books = Book.objects.annotate(Sum("publisher__num_awards")).order_by("name")
        self.assertQuerysetEqual(
            books, [
                ('Artificial Intelligence: A Modern Approach', 7),
                ('Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp', 9),
                ('Practical Django Projects', 3),
                ('Python Web Development with Django', 7),
                ('Sams Teach Yourself Django in 24 Hours', 1),
                ('The Definitive Guide to Django: Web Development Done Right', 3)
            ],
            lambda b: (b.name, b.publisher__num_awards__sum)
        )

        publishers = Publisher.objects.annotate(Sum("book__price")).order_by("name")
        self.assertQuerysetEqual(
            publishers, [
                ('Apress', Decimal("59.69")),
                ("Jonno's House of Books", None),
                ('Morgan Kaufmann', Decimal("75.00")),
                ('Prentice Hall', Decimal("112.49")),
                ('Sams', Decimal("23.09"))
            ],
            lambda p: (p.name, p.book__price__sum)
        )

    def test_annotate_values(self):
        books = list(Book.objects.filter(pk=1).annotate(mean_age=Avg("authors__age")).values())
        self.assertEqual(
            books, [
                {
                    "contact_id": 1,
                    "id": 1,
                    "isbn": "159059725",
                    "mean_age": 34.5,
                    "name": "The Definitive Guide to Django: Web Development Done Right",
                    "pages": 447,
                    "price": Approximate(Decimal("30")),
                    "pubdate": datetime.date(2007, 12, 6),
                    "publisher_id": 1,
                    "rating": 4.5,
                }
            ]
        )

        books = Book.objects.filter(pk=1).annotate(mean_age=Avg('authors__age')).values('pk', 'isbn', 'mean_age')
        self.assertEqual(
            list(books), [
                {
                    "pk": 1,
                    "isbn": "159059725",
                    "mean_age": 34.5,
                }
            ]
        )

        books = Book.objects.filter(pk=1).annotate(mean_age=Avg("authors__age")).values("name")
        self.assertEqual(
            list(books), [
                {
                    "name": "The Definitive Guide to Django: Web Development Done Right"
                }
            ]
        )

        books = Book.objects.filter(pk=1).values().annotate(mean_age=Avg('authors__age'))
        self.assertEqual(
            list(books), [
                {
                    "contact_id": 1,
                    "id": 1,
                    "isbn": "159059725",
                    "mean_age": 34.5,
                    "name": "The Definitive Guide to Django: Web Development Done Right",
                    "pages": 447,
                    "price": Approximate(Decimal("30")),
                    "pubdate": datetime.date(2007, 12, 6),
                    "publisher_id": 1,
                    "rating": 4.5,
                }
            ]
        )

        books = Book.objects.values("rating").annotate(n_authors=Count("authors__id"), mean_age=Avg("authors__age")).order_by("rating")
        self.assertEqual(
            list(books), [
                {
                    "rating": 3.0,
                    "n_authors": 1,
                    "mean_age": 45.0,
                },
                {
                    "rating": 4.0,
                    "n_authors": 6,
                    "mean_age": Approximate(37.16, places=1)
                },
                {
                    "rating": 4.5,
                    "n_authors": 2,
                    "mean_age": 34.5,
                },
                {
                    "rating": 5.0,
                    "n_authors": 1,
                    "mean_age": 57.0,
                }
            ]
        )

        authors = Author.objects.annotate(Avg("friends__age")).order_by("name")
        self.assertEqual(len(authors), 9)
        self.assertQuerysetEqual(
            authors, [
                ('Adrian Holovaty', 32.0),
                ('Brad Dayley', None),
                ('Jacob Kaplan-Moss', 29.5),
                ('James Bennett', 34.0),
                ('Jeffrey Forcier', 27.0),
                ('Paul Bissex', 31.0),
                ('Peter Norvig', 46.0),
                ('Stuart Russell', 57.0),
                ('Wesley J. Chun', Approximate(33.66, places=1))
            ],
            lambda a: (a.name, a.friends__age__avg)
        )

    def test_count(self):
        vals = Book.objects.aggregate(Count("rating"))
        self.assertEqual(vals, {"rating__count": 6})

        vals = Book.objects.aggregate(Count("rating", distinct=True))
        self.assertEqual(vals, {"rating__count": 4})

    def test_fkey_aggregate(self):
        explicit = list(Author.objects.annotate(Count('book__id')))
        implicit = list(Author.objects.annotate(Count('book')))
        self.assertEqual(explicit, implicit)

    def test_annotate_ordering(self):
        books = Book.objects.values('rating').annotate(oldest=Max('authors__age')).order_by('oldest', 'rating')
        self.assertEqual(
            list(books), [
                {
                    "rating": 4.5,
                    "oldest": 35,
                },
                {
                    "rating": 3.0,
                    "oldest": 45
                },
                {
                    "rating": 4.0,
                    "oldest": 57,
                },
                {
                    "rating": 5.0,
                    "oldest": 57,
                }
            ]
        )

        books = Book.objects.values("rating").annotate(oldest=Max("authors__age")).order_by("-oldest", "-rating")
        self.assertEqual(
            list(books), [
                {
                    "rating": 5.0,
                    "oldest": 57,
                },
                {
                    "rating": 4.0,
                    "oldest": 57,
                },
                {
                    "rating": 3.0,
                    "oldest": 45,
                },
                {
                    "rating": 4.5,
                    "oldest": 35,
                }
            ]
        )

    def test_aggregate_annotation(self):
        vals = Book.objects.annotate(num_authors=Count("authors__id")).aggregate(Avg("num_authors"))
        self.assertEqual(vals, {"num_authors__avg": Approximate(1.66, places=1)})

    def test_filtering(self):
        p = Publisher.objects.create(name='Expensive Publisher', num_awards=0)
        Book.objects.create(
            name='ExpensiveBook1',
            pages=1,
            isbn='111',
            rating=3.5,
            price=Decimal("1000"),
            publisher=p,
            contact_id=1,
            pubdate=datetime.date(2008, 12, 1)
        )
        Book.objects.create(
            name='ExpensiveBook2',
            pages=1,
            isbn='222',
            rating=4.0,
            price=Decimal("1000"),
            publisher=p,
            contact_id=1,
            pubdate=datetime.date(2008, 12, 2)
        )
        Book.objects.create(
            name='ExpensiveBook3',
            pages=1,
            isbn='333',
            rating=4.5,
            price=Decimal("35"),
            publisher=p,
            contact_id=1,
            pubdate=datetime.date(2008, 12, 3)
        )

        publishers = Publisher.objects.annotate(num_books=Count("book__id")).filter(num_books__gt=1).order_by("pk")
        self.assertQuerysetEqual(
            publishers, [
                "Apress",
                "Prentice Hall",
                "Expensive Publisher",
            ],
            lambda p: p.name,
        )

        publishers = Publisher.objects.filter(book__price__lt=Decimal("40.0")).order_by("pk")
        self.assertQuerysetEqual(
            publishers, [
                "Apress",
                "Apress",
                "Sams",
                "Prentice Hall",
                "Expensive Publisher",
            ],
            lambda p: p.name
        )

        publishers = Publisher.objects.annotate(num_books=Count("book__id")).filter(num_books__gt=1, book__price__lt=Decimal("40.0")).order_by("pk")
        self.assertQuerysetEqual(
            publishers, [
                "Apress",
                "Prentice Hall",
                "Expensive Publisher",
            ],
            lambda p: p.name,
        )

        publishers = Publisher.objects.filter(book__price__lt=Decimal("40.0")).annotate(num_books=Count("book__id")).filter(num_books__gt=1).order_by("pk")
        self.assertQuerysetEqual(
            publishers, [
                "Apress",
            ],
            lambda p: p.name
        )

        publishers = Publisher.objects.annotate(num_books=Count("book")).filter(num_books__range=[1, 3]).order_by("pk")
        self.assertQuerysetEqual(
            publishers, [
                "Apress",
                "Sams",
                "Prentice Hall",
                "Morgan Kaufmann",
                "Expensive Publisher",
            ],
            lambda p: p.name
        )

        publishers = Publisher.objects.annotate(num_books=Count("book")).filter(num_books__range=[1, 2]).order_by("pk")
        self.assertQuerysetEqual(
            publishers, [
                "Apress",
                "Sams",
                "Prentice Hall",
                "Morgan Kaufmann",
            ],
            lambda p: p.name
        )

        publishers = Publisher.objects.annotate(num_books=Count("book")).filter(num_books__in=[1, 3]).order_by("pk")
        self.assertQuerysetEqual(
            publishers, [
                "Sams",
                "Morgan Kaufmann",
                "Expensive Publisher",
            ],
            lambda p: p.name,
        )

        publishers = Publisher.objects.annotate(num_books=Count("book")).filter(num_books__isnull=True)
        self.assertEqual(len(publishers), 0)

    def test_annotation(self):
        vals = Author.objects.filter(pk=1).aggregate(Count("friends__id"))
        self.assertEqual(vals, {"friends__id__count": 2})

        books = Book.objects.annotate(num_authors=Count("authors__name")).filter(num_authors__exact=2).order_by("pk")
        self.assertQuerysetEqual(
            books, [
                "The Definitive Guide to Django: Web Development Done Right",
                "Artificial Intelligence: A Modern Approach",
            ],
            lambda b: b.name
        )

        authors = Author.objects.annotate(num_friends=Count("friends__id", distinct=True)).filter(num_friends=0).order_by("pk")
        self.assertQuerysetEqual(
            authors, [
                "Brad Dayley",
            ],
            lambda a: a.name
        )

        publishers = Publisher.objects.annotate(num_books=Count("book__id")).filter(num_books__gt=1).order_by("pk")
        self.assertQuerysetEqual(
            publishers, [
                "Apress",
                "Prentice Hall",
            ],
            lambda p: p.name
        )

        publishers = Publisher.objects.filter(book__price__lt=Decimal("40.0")).annotate(num_books=Count("book__id")).filter(num_books__gt=1)
        self.assertQuerysetEqual(
            publishers, [
                "Apress",
            ],
            lambda p: p.name
        )

        books = Book.objects.annotate(num_authors=Count("authors__id")).filter(authors__name__contains="Norvig", num_authors__gt=1)
        self.assertQuerysetEqual(
            books, [
                "Artificial Intelligence: A Modern Approach",
            ],
            lambda b: b.name
        )

    def test_more_aggregation(self):
        a = Author.objects.get(name__contains='Norvig')
        b = Book.objects.get(name__contains='Done Right')
        b.authors.add(a)
        b.save()

        vals = Book.objects.annotate(num_authors=Count("authors__id")).filter(authors__name__contains="Norvig", num_authors__gt=1).aggregate(Avg("rating"))
        self.assertEqual(vals, {"rating__avg": 4.25})

    def test_even_more_aggregate(self):
        publishers = Publisher.objects.annotate(earliest_book=Min("book__pubdate")).exclude(earliest_book=None).order_by("earliest_book").values()
        self.assertEqual(
            list(publishers), [
                {
                    'earliest_book': datetime.date(1991, 10, 15),
                    'num_awards': 9,
                    'id': 4,
                    'name': 'Morgan Kaufmann'
                },
                {
                    'earliest_book': datetime.date(1995, 1, 15),
                    'num_awards': 7,
                    'id': 3,
                    'name': 'Prentice Hall'
                },
                {
                    'earliest_book': datetime.date(2007, 12, 6),
                    'num_awards': 3,
                    'id': 1,
                    'name': 'Apress'
                },
                {
                    'earliest_book': datetime.date(2008, 3, 3),
                    'num_awards': 1,
                    'id': 2,
                    'name': 'Sams'
                }
            ]
        )

        vals = Store.objects.aggregate(Max("friday_night_closing"), Min("original_opening"))
        self.assertEqual(
            vals,
            {
                "friday_night_closing__max": datetime.time(23, 59, 59),
                "original_opening__min": datetime.datetime(1945, 4, 25, 16, 24, 14),
            }
        )

    def test_annotate_values_list(self):
        books = Book.objects.filter(pk=1).annotate(mean_age=Avg("authors__age")).values_list("pk", "isbn", "mean_age")
        self.assertEqual(
            list(books), [
                (1, "159059725", 34.5),
            ]
        )

        books = Book.objects.filter(pk=1).annotate(mean_age=Avg("authors__age")).values_list("isbn")
        self.assertEqual(
            list(books), [
                ('159059725',)
            ]
        )

        books = Book.objects.filter(pk=1).annotate(mean_age=Avg("authors__age")).values_list("mean_age")
        self.assertEqual(
            list(books), [
                (34.5,)
            ]
        )

        books = Book.objects.filter(pk=1).annotate(mean_age=Avg("authors__age")).values_list("mean_age", flat=True)
        self.assertEqual(list(books), [34.5])

        books = Book.objects.values_list("price").annotate(count=Count("price")).order_by("-count", "price")
        self.assertEqual(
            list(books), [
                (Decimal("29.69"), 2),
                (Decimal('23.09'), 1),
                (Decimal('30'), 1),
                (Decimal('75'), 1),
                (Decimal('82.8'), 1),
            ]
        )

    def test_dates_with_aggregation(self):
        """
        Test that .dates() returns a distinct set of dates when applied to a
        QuerySet with aggregation.

        Refs #18056. Previously, .dates() would return distinct (date_kind,
        aggregation) sets, in this case (year, num_authors), so 2008 would be
        returned twice because there are books from 2008 with a different
        number of authors.
        """
        dates = Book.objects.annotate(num_authors=Count("authors")).dates('pubdate', 'year')
        self.assertQuerysetEqual(
            dates, [
                "datetime.date(1991, 1, 1)",
                "datetime.date(1995, 1, 1)",
                "datetime.date(2007, 1, 1)",
                "datetime.date(2008, 1, 1)"
            ]
        )

    def test_values_aggregation(self):
        # Refs #20782
        max_rating = Book.objects.values('rating').aggregate(max_rating=Max('rating'))
        self.assertEqual(max_rating['max_rating'], 5)
        max_books_per_rating = Book.objects.values('rating').annotate(
            books_per_rating=Count('id')
        ).aggregate(Max('books_per_rating'))
        self.assertEqual(
            max_books_per_rating,
            {'books_per_rating__max': 3})

    def test_ticket17424(self):
        """
        Check that doing exclude() on a foreign model after annotate()
        doesn't crash.
        """
        all_books = list(Book.objects.values_list('pk', flat=True).order_by('pk'))
        annotated_books = Book.objects.order_by('pk').annotate(one=Count("id"))

        # The value doesn't matter, we just need any negative
        # constraint on a related model that's a noop.
        excluded_books = annotated_books.exclude(publisher__name="__UNLIKELY_VALUE__")

        # Try to generate query tree
        str(excluded_books.query)

        self.assertQuerysetEqual(excluded_books, all_books, lambda x: x.pk)

        # Check internal state
        self.assertIsNone(annotated_books.query.alias_map["aggregation_book"].join_type)
        self.assertIsNone(excluded_books.query.alias_map["aggregation_book"].join_type)

    def test_ticket12886(self):
        """
        Check that aggregation over sliced queryset works correctly.
        """
        qs = Book.objects.all().order_by('-rating')[0:3]
        vals = qs.aggregate(average_top3_rating=Avg('rating'))['average_top3_rating']
        self.assertAlmostEqual(vals, 4.5, places=2)

    def test_ticket11881(self):
        """
        Check that 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(forced_ordering).lower()]
                )
            else:
                self.assertNotIn('order by', qstr)
            self.assertEqual(qstr.count(' join '), 0)