import collections.abc
from datetime import datetime
from math import ceil
from operator import attrgetter

from django.core.exceptions import FieldError
from django.db import connection, models
from django.db.models import (
    BooleanField, Case, Exists, ExpressionWrapper, F, Max, OuterRef, Q,
    Subquery, Value, When,
)
from django.db.models.functions import Cast, Substr
from django.db.models.lookups import (
    Exact, GreaterThan, GreaterThanOrEqual, LessThan, LessThanOrEqual,
)
from django.test import TestCase, skipUnlessDBFeature
from django.test.utils import isolate_apps

from .models import (
    Article, Author, Freebie, Game, IsNullWithNoneAsRHS, Player, Product,
    Season, Stock, Tag,
)


class LookupTests(TestCase):

    @classmethod
    def setUpTestData(cls):
        # Create a few Authors.
        cls.au1 = Author.objects.create(name='Author 1', alias='a1')
        cls.au2 = Author.objects.create(name='Author 2', alias='a2')
        # Create a few Articles.
        cls.a1 = Article.objects.create(
            headline='Article 1',
            pub_date=datetime(2005, 7, 26),
            author=cls.au1,
            slug='a1',
        )
        cls.a2 = Article.objects.create(
            headline='Article 2',
            pub_date=datetime(2005, 7, 27),
            author=cls.au1,
            slug='a2',
        )
        cls.a3 = Article.objects.create(
            headline='Article 3',
            pub_date=datetime(2005, 7, 27),
            author=cls.au1,
            slug='a3',
        )
        cls.a4 = Article.objects.create(
            headline='Article 4',
            pub_date=datetime(2005, 7, 28),
            author=cls.au1,
            slug='a4',
        )
        cls.a5 = Article.objects.create(
            headline='Article 5',
            pub_date=datetime(2005, 8, 1, 9, 0),
            author=cls.au2,
            slug='a5',
        )
        cls.a6 = Article.objects.create(
            headline='Article 6',
            pub_date=datetime(2005, 8, 1, 8, 0),
            author=cls.au2,
            slug='a6',
        )
        cls.a7 = Article.objects.create(
            headline='Article 7',
            pub_date=datetime(2005, 7, 27),
            author=cls.au2,
            slug='a7',
        )
        # Create a few Tags.
        cls.t1 = Tag.objects.create(name='Tag 1')
        cls.t1.articles.add(cls.a1, cls.a2, cls.a3)
        cls.t2 = Tag.objects.create(name='Tag 2')
        cls.t2.articles.add(cls.a3, cls.a4, cls.a5)
        cls.t3 = Tag.objects.create(name='Tag 3')
        cls.t3.articles.add(cls.a5, cls.a6, cls.a7)

    def test_exists(self):
        # We can use .exists() to check that there are some
        self.assertTrue(Article.objects.exists())
        for a in Article.objects.all():
            a.delete()
        # There should be none now!
        self.assertFalse(Article.objects.exists())

    def test_lookup_int_as_str(self):
        # Integer value can be queried using string
        self.assertSequenceEqual(
            Article.objects.filter(id__iexact=str(self.a1.id)),
            [self.a1],
        )

    @skipUnlessDBFeature('supports_date_lookup_using_string')
    def test_lookup_date_as_str(self):
        # A date lookup can be performed using a string search
        self.assertSequenceEqual(
            Article.objects.filter(pub_date__startswith='2005'),
            [self.a5, self.a6, self.a4, self.a2, self.a3, self.a7, self.a1],
        )

    def test_iterator(self):
        # Each QuerySet gets iterator(), which is a generator that "lazily"
        # returns results using database-level iteration.
        self.assertIsInstance(Article.objects.iterator(), collections.abc.Iterator)

        self.assertQuerysetEqual(
            Article.objects.iterator(),
            [
                'Article 5',
                'Article 6',
                'Article 4',
                'Article 2',
                'Article 3',
                'Article 7',
                'Article 1',
            ],
            transform=attrgetter('headline')
        )
        # iterator() can be used on any QuerySet.
        self.assertQuerysetEqual(
            Article.objects.filter(headline__endswith='4').iterator(),
            ['Article 4'],
            transform=attrgetter('headline'))

    def test_count(self):
        # count() returns the number of objects matching search criteria.
        self.assertEqual(Article.objects.count(), 7)
        self.assertEqual(Article.objects.filter(pub_date__exact=datetime(2005, 7, 27)).count(), 3)
        self.assertEqual(Article.objects.filter(headline__startswith='Blah blah').count(), 0)

        # count() should respect sliced query sets.
        articles = Article.objects.all()
        self.assertEqual(articles.count(), 7)
        self.assertEqual(articles[:4].count(), 4)
        self.assertEqual(articles[1:100].count(), 6)
        self.assertEqual(articles[10:100].count(), 0)

        # Date and date/time lookups can also be done with strings.
        self.assertEqual(Article.objects.filter(pub_date__exact='2005-07-27 00:00:00').count(), 3)

    def test_in_bulk(self):
        # in_bulk() takes a list of IDs and returns a dictionary mapping IDs to objects.
        arts = Article.objects.in_bulk([self.a1.id, self.a2.id])
        self.assertEqual(arts[self.a1.id], self.a1)
        self.assertEqual(arts[self.a2.id], self.a2)
        self.assertEqual(
            Article.objects.in_bulk(),
            {
                self.a1.id: self.a1,
                self.a2.id: self.a2,
                self.a3.id: self.a3,
                self.a4.id: self.a4,
                self.a5.id: self.a5,
                self.a6.id: self.a6,
                self.a7.id: self.a7,
            }
        )
        self.assertEqual(Article.objects.in_bulk([self.a3.id]), {self.a3.id: self.a3})
        self.assertEqual(Article.objects.in_bulk({self.a3.id}), {self.a3.id: self.a3})
        self.assertEqual(Article.objects.in_bulk(frozenset([self.a3.id])), {self.a3.id: self.a3})
        self.assertEqual(Article.objects.in_bulk((self.a3.id,)), {self.a3.id: self.a3})
        self.assertEqual(Article.objects.in_bulk([1000]), {})
        self.assertEqual(Article.objects.in_bulk([]), {})
        self.assertEqual(Article.objects.in_bulk(iter([self.a1.id])), {self.a1.id: self.a1})
        self.assertEqual(Article.objects.in_bulk(iter([])), {})
        with self.assertRaises(TypeError):
            Article.objects.in_bulk(headline__startswith='Blah')

    def test_in_bulk_lots_of_ids(self):
        test_range = 2000
        max_query_params = connection.features.max_query_params
        expected_num_queries = ceil(test_range / max_query_params) if max_query_params else 1
        Author.objects.bulk_create([Author() for i in range(test_range - Author.objects.count())])
        authors = {author.pk: author for author in Author.objects.all()}
        with self.assertNumQueries(expected_num_queries):
            self.assertEqual(Author.objects.in_bulk(authors), authors)

    def test_in_bulk_with_field(self):
        self.assertEqual(
            Article.objects.in_bulk([self.a1.slug, self.a2.slug, self.a3.slug], field_name='slug'),
            {
                self.a1.slug: self.a1,
                self.a2.slug: self.a2,
                self.a3.slug: self.a3,
            }
        )

    def test_in_bulk_meta_constraint(self):
        season_2011 = Season.objects.create(year=2011)
        season_2012 = Season.objects.create(year=2012)
        Season.objects.create(year=2013)
        self.assertEqual(
            Season.objects.in_bulk(
                [season_2011.year, season_2012.year],
                field_name='year',
            ),
            {season_2011.year: season_2011, season_2012.year: season_2012},
        )

    def test_in_bulk_non_unique_field(self):
        msg = "in_bulk()'s field_name must be a unique field but 'author' isn't."
        with self.assertRaisesMessage(ValueError, msg):
            Article.objects.in_bulk([self.au1], field_name='author')

    @skipUnlessDBFeature('can_distinct_on_fields')
    def test_in_bulk_distinct_field(self):
        self.assertEqual(
            Article.objects.order_by('headline').distinct('headline').in_bulk(
                [self.a1.headline, self.a5.headline],
                field_name='headline',
            ),
            {self.a1.headline: self.a1, self.a5.headline: self.a5},
        )

    @skipUnlessDBFeature('can_distinct_on_fields')
    def test_in_bulk_multiple_distinct_field(self):
        msg = "in_bulk()'s field_name must be a unique field but 'pub_date' isn't."
        with self.assertRaisesMessage(ValueError, msg):
            Article.objects.order_by('headline', 'pub_date').distinct(
                'headline', 'pub_date',
            ).in_bulk(field_name='pub_date')

    @isolate_apps('lookup')
    def test_in_bulk_non_unique_meta_constaint(self):
        class Model(models.Model):
            ean = models.CharField(max_length=100)
            brand = models.CharField(max_length=100)
            name = models.CharField(max_length=80)

            class Meta:
                constraints = [
                    models.UniqueConstraint(
                        fields=['ean'],
                        name='partial_ean_unique',
                        condition=models.Q(is_active=True)
                    ),
                    models.UniqueConstraint(
                        fields=['brand', 'name'],
                        name='together_brand_name_unique',
                    ),
                ]

        msg = "in_bulk()'s field_name must be a unique field but '%s' isn't."
        for field_name in ['brand', 'ean']:
            with self.subTest(field_name=field_name):
                with self.assertRaisesMessage(ValueError, msg % field_name):
                    Model.objects.in_bulk(field_name=field_name)

    def test_in_bulk_sliced_queryset(self):
        msg = "Cannot use 'limit' or 'offset' with in_bulk()."
        with self.assertRaisesMessage(TypeError, msg):
            Article.objects.all()[0:5].in_bulk([self.a1.id, self.a2.id])

    def test_values(self):
        # values() returns a list of dictionaries instead of object instances --
        # and you can specify which fields you want to retrieve.
        self.assertSequenceEqual(
            Article.objects.values('headline'),
            [
                {'headline': 'Article 5'},
                {'headline': 'Article 6'},
                {'headline': 'Article 4'},
                {'headline': 'Article 2'},
                {'headline': 'Article 3'},
                {'headline': 'Article 7'},
                {'headline': 'Article 1'},
            ],
        )
        self.assertSequenceEqual(
            Article.objects.filter(pub_date__exact=datetime(2005, 7, 27)).values('id'),
            [{'id': self.a2.id}, {'id': self.a3.id}, {'id': self.a7.id}],
        )
        self.assertSequenceEqual(
            Article.objects.values('id', 'headline'),
            [
                {'id': self.a5.id, 'headline': 'Article 5'},
                {'id': self.a6.id, 'headline': 'Article 6'},
                {'id': self.a4.id, 'headline': 'Article 4'},
                {'id': self.a2.id, 'headline': 'Article 2'},
                {'id': self.a3.id, 'headline': 'Article 3'},
                {'id': self.a7.id, 'headline': 'Article 7'},
                {'id': self.a1.id, 'headline': 'Article 1'},
            ],
        )
        # You can use values() with iterator() for memory savings,
        # because iterator() uses database-level iteration.
        self.assertSequenceEqual(
            list(Article.objects.values('id', 'headline').iterator()),
            [
                {'headline': 'Article 5', 'id': self.a5.id},
                {'headline': 'Article 6', 'id': self.a6.id},
                {'headline': 'Article 4', 'id': self.a4.id},
                {'headline': 'Article 2', 'id': self.a2.id},
                {'headline': 'Article 3', 'id': self.a3.id},
                {'headline': 'Article 7', 'id': self.a7.id},
                {'headline': 'Article 1', 'id': self.a1.id},
            ],
        )
        # The values() method works with "extra" fields specified in extra(select).
        self.assertSequenceEqual(
            Article.objects.extra(select={'id_plus_one': 'id + 1'}).values('id', 'id_plus_one'),
            [
                {'id': self.a5.id, 'id_plus_one': self.a5.id + 1},
                {'id': self.a6.id, 'id_plus_one': self.a6.id + 1},
                {'id': self.a4.id, 'id_plus_one': self.a4.id + 1},
                {'id': self.a2.id, 'id_plus_one': self.a2.id + 1},
                {'id': self.a3.id, 'id_plus_one': self.a3.id + 1},
                {'id': self.a7.id, 'id_plus_one': self.a7.id + 1},
                {'id': self.a1.id, 'id_plus_one': self.a1.id + 1},
            ],
        )
        data = {
            'id_plus_one': 'id+1',
            'id_plus_two': 'id+2',
            'id_plus_three': 'id+3',
            'id_plus_four': 'id+4',
            'id_plus_five': 'id+5',
            'id_plus_six': 'id+6',
            'id_plus_seven': 'id+7',
            'id_plus_eight': 'id+8',
        }
        self.assertSequenceEqual(
            Article.objects.filter(id=self.a1.id).extra(select=data).values(*data),
            [{
                'id_plus_one': self.a1.id + 1,
                'id_plus_two': self.a1.id + 2,
                'id_plus_three': self.a1.id + 3,
                'id_plus_four': self.a1.id + 4,
                'id_plus_five': self.a1.id + 5,
                'id_plus_six': self.a1.id + 6,
                'id_plus_seven': self.a1.id + 7,
                'id_plus_eight': self.a1.id + 8,
            }],
        )
        # You can specify fields from forward and reverse relations, just like filter().
        self.assertSequenceEqual(
            Article.objects.values('headline', 'author__name'),
            [
                {'headline': self.a5.headline, 'author__name': self.au2.name},
                {'headline': self.a6.headline, 'author__name': self.au2.name},
                {'headline': self.a4.headline, 'author__name': self.au1.name},
                {'headline': self.a2.headline, 'author__name': self.au1.name},
                {'headline': self.a3.headline, 'author__name': self.au1.name},
                {'headline': self.a7.headline, 'author__name': self.au2.name},
                {'headline': self.a1.headline, 'author__name': self.au1.name},
            ],
        )
        self.assertSequenceEqual(
            Author.objects.values('name', 'article__headline').order_by('name', 'article__headline'),
            [
                {'name': self.au1.name, 'article__headline': self.a1.headline},
                {'name': self.au1.name, 'article__headline': self.a2.headline},
                {'name': self.au1.name, 'article__headline': self.a3.headline},
                {'name': self.au1.name, 'article__headline': self.a4.headline},
                {'name': self.au2.name, 'article__headline': self.a5.headline},
                {'name': self.au2.name, 'article__headline': self.a6.headline},
                {'name': self.au2.name, 'article__headline': self.a7.headline},
            ],
        )
        self.assertSequenceEqual(
            (
                Author.objects
                .values('name', 'article__headline', 'article__tag__name')
                .order_by('name', 'article__headline', 'article__tag__name')
            ),
            [
                {'name': self.au1.name, 'article__headline': self.a1.headline, 'article__tag__name': self.t1.name},
                {'name': self.au1.name, 'article__headline': self.a2.headline, 'article__tag__name': self.t1.name},
                {'name': self.au1.name, 'article__headline': self.a3.headline, 'article__tag__name': self.t1.name},
                {'name': self.au1.name, 'article__headline': self.a3.headline, 'article__tag__name': self.t2.name},
                {'name': self.au1.name, 'article__headline': self.a4.headline, 'article__tag__name': self.t2.name},
                {'name': self.au2.name, 'article__headline': self.a5.headline, 'article__tag__name': self.t2.name},
                {'name': self.au2.name, 'article__headline': self.a5.headline, 'article__tag__name': self.t3.name},
                {'name': self.au2.name, 'article__headline': self.a6.headline, 'article__tag__name': self.t3.name},
                {'name': self.au2.name, 'article__headline': self.a7.headline, 'article__tag__name': self.t3.name},
            ],
        )
        # However, an exception FieldDoesNotExist will be thrown if you specify
        # a nonexistent field name in values() (a field that is neither in the
        # model nor in extra(select)).
        msg = (
            "Cannot resolve keyword 'id_plus_two' into field. Choices are: "
            "author, author_id, headline, id, id_plus_one, pub_date, slug, tag"
        )
        with self.assertRaisesMessage(FieldError, msg):
            Article.objects.extra(select={'id_plus_one': 'id + 1'}).values('id', 'id_plus_two')
        # If you don't specify field names to values(), all are returned.
        self.assertSequenceEqual(
            Article.objects.filter(id=self.a5.id).values(),
            [{
                'id': self.a5.id,
                'author_id': self.au2.id,
                'headline': 'Article 5',
                'pub_date': datetime(2005, 8, 1, 9, 0),
                'slug': 'a5',
            }],
        )

    def test_values_list(self):
        # values_list() is similar to values(), except that the results are
        # returned as a list of tuples, rather than a list of dictionaries.
        # Within each tuple, the order of the elements is the same as the order
        # of fields in the values_list() call.
        self.assertSequenceEqual(
            Article.objects.values_list('headline'),
            [
                ('Article 5',),
                ('Article 6',),
                ('Article 4',),
                ('Article 2',),
                ('Article 3',),
                ('Article 7',),
                ('Article 1',),
            ],
        )
        self.assertSequenceEqual(
            Article.objects.values_list('id').order_by('id'),
            [(self.a1.id,), (self.a2.id,), (self.a3.id,), (self.a4.id,), (self.a5.id,), (self.a6.id,), (self.a7.id,)],
        )
        self.assertSequenceEqual(
            Article.objects.values_list('id', flat=True).order_by('id'),
            [self.a1.id, self.a2.id, self.a3.id, self.a4.id, self.a5.id, self.a6.id, self.a7.id],
        )
        self.assertSequenceEqual(
            Article.objects.extra(select={'id_plus_one': 'id+1'}).order_by('id').values_list('id'),
            [(self.a1.id,), (self.a2.id,), (self.a3.id,), (self.a4.id,), (self.a5.id,), (self.a6.id,), (self.a7.id,)],
        )
        self.assertSequenceEqual(
            Article.objects.extra(select={'id_plus_one': 'id+1'}).order_by('id').values_list('id_plus_one', 'id'),
            [
                (self.a1.id + 1, self.a1.id),
                (self.a2.id + 1, self.a2.id),
                (self.a3.id + 1, self.a3.id),
                (self.a4.id + 1, self.a4.id),
                (self.a5.id + 1, self.a5.id),
                (self.a6.id + 1, self.a6.id),
                (self.a7.id + 1, self.a7.id)
            ],
        )
        self.assertSequenceEqual(
            Article.objects.extra(select={'id_plus_one': 'id+1'}).order_by('id').values_list('id', 'id_plus_one'),
            [
                (self.a1.id, self.a1.id + 1),
                (self.a2.id, self.a2.id + 1),
                (self.a3.id, self.a3.id + 1),
                (self.a4.id, self.a4.id + 1),
                (self.a5.id, self.a5.id + 1),
                (self.a6.id, self.a6.id + 1),
                (self.a7.id, self.a7.id + 1)
            ],
        )
        args = ('name', 'article__headline', 'article__tag__name')
        self.assertSequenceEqual(
            Author.objects.values_list(*args).order_by(*args),
            [
                (self.au1.name, self.a1.headline, self.t1.name),
                (self.au1.name, self.a2.headline, self.t1.name),
                (self.au1.name, self.a3.headline, self.t1.name),
                (self.au1.name, self.a3.headline, self.t2.name),
                (self.au1.name, self.a4.headline, self.t2.name),
                (self.au2.name, self.a5.headline, self.t2.name),
                (self.au2.name, self.a5.headline, self.t3.name),
                (self.au2.name, self.a6.headline, self.t3.name),
                (self.au2.name, self.a7.headline, self.t3.name),
            ],
        )
        with self.assertRaises(TypeError):
            Article.objects.values_list('id', 'headline', flat=True)

    def test_get_next_previous_by(self):
        # Every DateField and DateTimeField creates get_next_by_FOO() and
        # get_previous_by_FOO() methods. In the case of identical date values,
        # these methods will use the ID as a fallback check. This guarantees
        # that no records are skipped or duplicated.
        self.assertEqual(repr(self.a1.get_next_by_pub_date()), '<Article: Article 2>')
        self.assertEqual(repr(self.a2.get_next_by_pub_date()), '<Article: Article 3>')
        self.assertEqual(repr(self.a2.get_next_by_pub_date(headline__endswith='6')), '<Article: Article 6>')
        self.assertEqual(repr(self.a3.get_next_by_pub_date()), '<Article: Article 7>')
        self.assertEqual(repr(self.a4.get_next_by_pub_date()), '<Article: Article 6>')
        with self.assertRaises(Article.DoesNotExist):
            self.a5.get_next_by_pub_date()
        self.assertEqual(repr(self.a6.get_next_by_pub_date()), '<Article: Article 5>')
        self.assertEqual(repr(self.a7.get_next_by_pub_date()), '<Article: Article 4>')

        self.assertEqual(repr(self.a7.get_previous_by_pub_date()), '<Article: Article 3>')
        self.assertEqual(repr(self.a6.get_previous_by_pub_date()), '<Article: Article 4>')
        self.assertEqual(repr(self.a5.get_previous_by_pub_date()), '<Article: Article 6>')
        self.assertEqual(repr(self.a4.get_previous_by_pub_date()), '<Article: Article 7>')
        self.assertEqual(repr(self.a3.get_previous_by_pub_date()), '<Article: Article 2>')
        self.assertEqual(repr(self.a2.get_previous_by_pub_date()), '<Article: Article 1>')

    def test_escaping(self):
        # Underscores, percent signs and backslashes have special meaning in the
        # underlying SQL code, but Django handles the quoting of them automatically.
        a8 = Article.objects.create(headline='Article_ with underscore', pub_date=datetime(2005, 11, 20))

        self.assertSequenceEqual(
            Article.objects.filter(headline__startswith='Article'),
            [a8, self.a5, self.a6, self.a4, self.a2, self.a3, self.a7, self.a1],
        )
        self.assertSequenceEqual(
            Article.objects.filter(headline__startswith='Article_'),
            [a8],
        )
        a9 = Article.objects.create(headline='Article% with percent sign', pub_date=datetime(2005, 11, 21))
        self.assertSequenceEqual(
            Article.objects.filter(headline__startswith='Article'),
            [a9, a8, self.a5, self.a6, self.a4, self.a2, self.a3, self.a7, self.a1],
        )
        self.assertSequenceEqual(
            Article.objects.filter(headline__startswith='Article%'),
            [a9],
        )
        a10 = Article.objects.create(headline='Article with \\ backslash', pub_date=datetime(2005, 11, 22))
        self.assertSequenceEqual(
            Article.objects.filter(headline__contains='\\'),
            [a10],
        )

    def test_exclude(self):
        pub_date = datetime(2005, 11, 20)
        a8 = Article.objects.create(headline='Article_ with underscore', pub_date=pub_date)
        a9 = Article.objects.create(headline='Article% with percent sign', pub_date=pub_date)
        a10 = Article.objects.create(headline='Article with \\ backslash', pub_date=pub_date)
        # exclude() is the opposite of filter() when doing lookups:
        self.assertSequenceEqual(
            Article.objects.filter(headline__contains='Article').exclude(headline__contains='with'),
            [self.a5, self.a6, self.a4, self.a2, self.a3, self.a7, self.a1],
        )
        self.assertSequenceEqual(
            Article.objects.exclude(headline__startswith="Article_"),
            [a10, a9, self.a5, self.a6, self.a4, self.a2, self.a3, self.a7, self.a1],
        )
        self.assertSequenceEqual(
            Article.objects.exclude(headline="Article 7"),
            [a10, a9, a8, self.a5, self.a6, self.a4, self.a2, self.a3, self.a1],
        )

    def test_none(self):
        # none() returns a QuerySet that behaves like any other QuerySet object
        self.assertQuerysetEqual(Article.objects.none(), [])
        self.assertQuerysetEqual(Article.objects.none().filter(headline__startswith='Article'), [])
        self.assertQuerysetEqual(Article.objects.filter(headline__startswith='Article').none(), [])
        self.assertEqual(Article.objects.none().count(), 0)
        self.assertEqual(Article.objects.none().update(headline="This should not take effect"), 0)
        self.assertQuerysetEqual(Article.objects.none().iterator(), [])

    def test_in(self):
        self.assertSequenceEqual(
            Article.objects.exclude(id__in=[]),
            [self.a5, self.a6, self.a4, self.a2, self.a3, self.a7, self.a1],
        )

    def test_in_empty_list(self):
        self.assertSequenceEqual(Article.objects.filter(id__in=[]), [])

    def test_in_different_database(self):
        with self.assertRaisesMessage(
            ValueError,
            "Subqueries aren't allowed across different databases. Force the "
            "inner query to be evaluated using `list(inner_query)`."
        ):
            list(Article.objects.filter(id__in=Article.objects.using('other').all()))

    def test_in_keeps_value_ordering(self):
        query = Article.objects.filter(slug__in=['a%d' % i for i in range(1, 8)]).values('pk').query
        self.assertIn(' IN (a1, a2, a3, a4, a5, a6, a7) ', str(query))

    def test_in_ignore_none(self):
        with self.assertNumQueries(1) as ctx:
            self.assertSequenceEqual(
                Article.objects.filter(id__in=[None, self.a1.id]),
                [self.a1],
            )
        sql = ctx.captured_queries[0]['sql']
        self.assertIn('IN (%s)' % self.a1.pk, sql)

    def test_in_ignore_solo_none(self):
        with self.assertNumQueries(0):
            self.assertSequenceEqual(Article.objects.filter(id__in=[None]), [])

    def test_in_ignore_none_with_unhashable_items(self):
        class UnhashableInt(int):
            __hash__ = None

        with self.assertNumQueries(1) as ctx:
            self.assertSequenceEqual(
                Article.objects.filter(id__in=[None, UnhashableInt(self.a1.id)]),
                [self.a1],
            )
        sql = ctx.captured_queries[0]['sql']
        self.assertIn('IN (%s)' % self.a1.pk, sql)

    def test_error_messages(self):
        # Programming errors are pointed out with nice error messages
        with self.assertRaisesMessage(
            FieldError,
            "Cannot resolve keyword 'pub_date_year' into field. Choices are: "
            "author, author_id, headline, id, pub_date, slug, tag"
        ):
            Article.objects.filter(pub_date_year='2005').count()

    def test_unsupported_lookups(self):
        with self.assertRaisesMessage(
            FieldError,
            "Unsupported lookup 'starts' for CharField or join on the field "
            "not permitted, perhaps you meant startswith or istartswith?"
        ):
            Article.objects.filter(headline__starts='Article')

        with self.assertRaisesMessage(
            FieldError,
            "Unsupported lookup 'is_null' for DateTimeField or join on the field "
            "not permitted, perhaps you meant isnull?"
        ):
            Article.objects.filter(pub_date__is_null=True)

        with self.assertRaisesMessage(
            FieldError,
            "Unsupported lookup 'gobbledygook' for DateTimeField or join on the field "
            "not permitted."
        ):
            Article.objects.filter(pub_date__gobbledygook='blahblah')

    def test_relation_nested_lookup_error(self):
        # An invalid nested lookup on a related field raises a useful error.
        msg = 'Related Field got invalid lookup: editor'
        with self.assertRaisesMessage(FieldError, msg):
            Article.objects.filter(author__editor__name='James')
        msg = 'Related Field got invalid lookup: foo'
        with self.assertRaisesMessage(FieldError, msg):
            Tag.objects.filter(articles__foo='bar')

    def test_regex(self):
        # Create some articles with a bit more interesting headlines for testing field lookups:
        for a in Article.objects.all():
            a.delete()
        now = datetime.now()
        Article.objects.bulk_create([
            Article(pub_date=now, headline='f'),
            Article(pub_date=now, headline='fo'),
            Article(pub_date=now, headline='foo'),
            Article(pub_date=now, headline='fooo'),
            Article(pub_date=now, headline='hey-Foo'),
            Article(pub_date=now, headline='bar'),
            Article(pub_date=now, headline='AbBa'),
            Article(pub_date=now, headline='baz'),
            Article(pub_date=now, headline='baxZ'),
        ])
        # zero-or-more
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'fo*'),
            Article.objects.filter(headline__in=['f', 'fo', 'foo', 'fooo']),
        )
        self.assertQuerysetEqual(
            Article.objects.filter(headline__iregex=r'fo*'),
            Article.objects.filter(headline__in=['f', 'fo', 'foo', 'fooo', 'hey-Foo']),
        )
        # one-or-more
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'fo+'),
            Article.objects.filter(headline__in=['fo', 'foo', 'fooo']),
        )
        # wildcard
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'fooo?'),
            Article.objects.filter(headline__in=['foo', 'fooo']),
        )
        # leading anchor
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'^b'),
            Article.objects.filter(headline__in=['bar', 'baxZ', 'baz']),
        )
        self.assertQuerysetEqual(
            Article.objects.filter(headline__iregex=r'^a'),
            Article.objects.filter(headline='AbBa'),
        )
        # trailing anchor
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'z$'),
            Article.objects.filter(headline='baz'),
        )
        self.assertQuerysetEqual(
            Article.objects.filter(headline__iregex=r'z$'),
            Article.objects.filter(headline__in=['baxZ', 'baz']),
        )
        # character sets
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'ba[rz]'),
            Article.objects.filter(headline__in=['bar', 'baz']),
        )
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'ba.[RxZ]'),
            Article.objects.filter(headline='baxZ'),
        )
        self.assertQuerysetEqual(
            Article.objects.filter(headline__iregex=r'ba[RxZ]'),
            Article.objects.filter(headline__in=['bar', 'baxZ', 'baz']),
        )

        # and more articles:
        Article.objects.bulk_create([
            Article(pub_date=now, headline='foobar'),
            Article(pub_date=now, headline='foobaz'),
            Article(pub_date=now, headline='ooF'),
            Article(pub_date=now, headline='foobarbaz'),
            Article(pub_date=now, headline='zoocarfaz'),
            Article(pub_date=now, headline='barfoobaz'),
            Article(pub_date=now, headline='bazbaRFOO'),
        ])

        # alternation
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'oo(f|b)'),
            Article.objects.filter(headline__in=[
                'barfoobaz',
                'foobar',
                'foobarbaz',
                'foobaz',
            ]),
        )
        self.assertQuerysetEqual(
            Article.objects.filter(headline__iregex=r'oo(f|b)'),
            Article.objects.filter(headline__in=[
                'barfoobaz',
                'foobar',
                'foobarbaz',
                'foobaz',
                'ooF',
            ]),
        )
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'^foo(f|b)'),
            Article.objects.filter(headline__in=['foobar', 'foobarbaz', 'foobaz']),
        )

        # greedy matching
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'b.*az'),
            Article.objects.filter(headline__in=[
                'barfoobaz',
                'baz',
                'bazbaRFOO',
                'foobarbaz',
                'foobaz',
            ]),
        )
        self.assertQuerysetEqual(
            Article.objects.filter(headline__iregex=r'b.*ar'),
            Article.objects.filter(headline__in=[
                'bar',
                'barfoobaz',
                'bazbaRFOO',
                'foobar',
                'foobarbaz',
            ]),
        )

    @skipUnlessDBFeature('supports_regex_backreferencing')
    def test_regex_backreferencing(self):
        # grouping and backreferences
        now = datetime.now()
        Article.objects.bulk_create([
            Article(pub_date=now, headline='foobar'),
            Article(pub_date=now, headline='foobaz'),
            Article(pub_date=now, headline='ooF'),
            Article(pub_date=now, headline='foobarbaz'),
            Article(pub_date=now, headline='zoocarfaz'),
            Article(pub_date=now, headline='barfoobaz'),
            Article(pub_date=now, headline='bazbaRFOO'),
        ])
        self.assertQuerysetEqual(
            Article.objects.filter(headline__regex=r'b(.).*b\1').values_list('headline', flat=True),
            ['barfoobaz', 'bazbaRFOO', 'foobarbaz'],
        )

    def test_regex_null(self):
        """
        A regex lookup does not fail on null/None values
        """
        Season.objects.create(year=2012, gt=None)
        self.assertQuerysetEqual(Season.objects.filter(gt__regex=r'^$'), [])

    def test_regex_non_string(self):
        """
        A regex lookup does not fail on non-string fields
        """
        s = Season.objects.create(year=2013, gt=444)
        self.assertQuerysetEqual(Season.objects.filter(gt__regex=r'^444$'), [s])

    def test_regex_non_ascii(self):
        """
        A regex lookup does not trip on non-ASCII characters.
        """
        Player.objects.create(name='\u2660')
        Player.objects.get(name__regex='\u2660')

    def test_nonfield_lookups(self):
        """
        A lookup query containing non-fields raises the proper exception.
        """
        msg = "Unsupported lookup 'blahblah' for CharField or join on the field not permitted."
        with self.assertRaisesMessage(FieldError, msg):
            Article.objects.filter(headline__blahblah=99)
        with self.assertRaisesMessage(FieldError, msg):
            Article.objects.filter(headline__blahblah__exact=99)
        msg = (
            "Cannot resolve keyword 'blahblah' into field. Choices are: "
            "author, author_id, headline, id, pub_date, slug, tag"
        )
        with self.assertRaisesMessage(FieldError, msg):
            Article.objects.filter(blahblah=99)

    def test_lookup_collision(self):
        """
        Genuine field names don't collide with built-in lookup types
        ('year', 'gt', 'range', 'in' etc.) (#11670).
        """
        # 'gt' is used as a code number for the year, e.g. 111=>2009.
        season_2009 = Season.objects.create(year=2009, gt=111)
        season_2009.games.create(home="Houston Astros", away="St. Louis Cardinals")
        season_2010 = Season.objects.create(year=2010, gt=222)
        season_2010.games.create(home="Houston Astros", away="Chicago Cubs")
        season_2010.games.create(home="Houston Astros", away="Milwaukee Brewers")
        season_2010.games.create(home="Houston Astros", away="St. Louis Cardinals")
        season_2011 = Season.objects.create(year=2011, gt=333)
        season_2011.games.create(home="Houston Astros", away="St. Louis Cardinals")
        season_2011.games.create(home="Houston Astros", away="Milwaukee Brewers")
        hunter_pence = Player.objects.create(name="Hunter Pence")
        hunter_pence.games.set(Game.objects.filter(season__year__in=[2009, 2010]))
        pudge = Player.objects.create(name="Ivan Rodriquez")
        pudge.games.set(Game.objects.filter(season__year=2009))
        pedro_feliz = Player.objects.create(name="Pedro Feliz")
        pedro_feliz.games.set(Game.objects.filter(season__year__in=[2011]))
        johnson = Player.objects.create(name="Johnson")
        johnson.games.set(Game.objects.filter(season__year__in=[2011]))

        # Games in 2010
        self.assertEqual(Game.objects.filter(season__year=2010).count(), 3)
        self.assertEqual(Game.objects.filter(season__year__exact=2010).count(), 3)
        self.assertEqual(Game.objects.filter(season__gt=222).count(), 3)
        self.assertEqual(Game.objects.filter(season__gt__exact=222).count(), 3)

        # Games in 2011
        self.assertEqual(Game.objects.filter(season__year=2011).count(), 2)
        self.assertEqual(Game.objects.filter(season__year__exact=2011).count(), 2)
        self.assertEqual(Game.objects.filter(season__gt=333).count(), 2)
        self.assertEqual(Game.objects.filter(season__gt__exact=333).count(), 2)
        self.assertEqual(Game.objects.filter(season__year__gt=2010).count(), 2)
        self.assertEqual(Game.objects.filter(season__gt__gt=222).count(), 2)

        # Games played in 2010 and 2011
        self.assertEqual(Game.objects.filter(season__year__in=[2010, 2011]).count(), 5)
        self.assertEqual(Game.objects.filter(season__year__gt=2009).count(), 5)
        self.assertEqual(Game.objects.filter(season__gt__in=[222, 333]).count(), 5)
        self.assertEqual(Game.objects.filter(season__gt__gt=111).count(), 5)

        # Players who played in 2009
        self.assertEqual(Player.objects.filter(games__season__year=2009).distinct().count(), 2)
        self.assertEqual(Player.objects.filter(games__season__year__exact=2009).distinct().count(), 2)
        self.assertEqual(Player.objects.filter(games__season__gt=111).distinct().count(), 2)
        self.assertEqual(Player.objects.filter(games__season__gt__exact=111).distinct().count(), 2)

        # Players who played in 2010
        self.assertEqual(Player.objects.filter(games__season__year=2010).distinct().count(), 1)
        self.assertEqual(Player.objects.filter(games__season__year__exact=2010).distinct().count(), 1)
        self.assertEqual(Player.objects.filter(games__season__gt=222).distinct().count(), 1)
        self.assertEqual(Player.objects.filter(games__season__gt__exact=222).distinct().count(), 1)

        # Players who played in 2011
        self.assertEqual(Player.objects.filter(games__season__year=2011).distinct().count(), 2)
        self.assertEqual(Player.objects.filter(games__season__year__exact=2011).distinct().count(), 2)
        self.assertEqual(Player.objects.filter(games__season__gt=333).distinct().count(), 2)
        self.assertEqual(Player.objects.filter(games__season__year__gt=2010).distinct().count(), 2)
        self.assertEqual(Player.objects.filter(games__season__gt__gt=222).distinct().count(), 2)

    def test_chain_date_time_lookups(self):
        self.assertCountEqual(
            Article.objects.filter(pub_date__month__gt=7),
            [self.a5, self.a6],
        )
        self.assertCountEqual(
            Article.objects.filter(pub_date__day__gte=27),
            [self.a2, self.a3, self.a4, self.a7],
        )
        self.assertCountEqual(
            Article.objects.filter(pub_date__hour__lt=8),
            [self.a1, self.a2, self.a3, self.a4, self.a7],
        )
        self.assertCountEqual(
            Article.objects.filter(pub_date__minute__lte=0),
            [self.a1, self.a2, self.a3, self.a4, self.a5, self.a6, self.a7],
        )

    def test_exact_none_transform(self):
        """Transforms are used for __exact=None."""
        Season.objects.create(year=1, nulled_text_field='not null')
        self.assertFalse(Season.objects.filter(nulled_text_field__isnull=True))
        self.assertTrue(Season.objects.filter(nulled_text_field__nulled__isnull=True))
        self.assertTrue(Season.objects.filter(nulled_text_field__nulled__exact=None))
        self.assertTrue(Season.objects.filter(nulled_text_field__nulled=None))

    def test_exact_sliced_queryset_limit_one(self):
        self.assertCountEqual(
            Article.objects.filter(author=Author.objects.all()[:1]),
            [self.a1, self.a2, self.a3, self.a4]
        )

    def test_exact_sliced_queryset_limit_one_offset(self):
        self.assertCountEqual(
            Article.objects.filter(author=Author.objects.all()[1:2]),
            [self.a5, self.a6, self.a7]
        )

    def test_exact_sliced_queryset_not_limited_to_one(self):
        msg = (
            'The QuerySet value for an exact lookup must be limited to one '
            'result using slicing.'
        )
        with self.assertRaisesMessage(ValueError, msg):
            list(Article.objects.filter(author=Author.objects.all()[:2]))
        with self.assertRaisesMessage(ValueError, msg):
            list(Article.objects.filter(author=Author.objects.all()[1:]))

    def test_custom_field_none_rhs(self):
        """
        __exact=value is transformed to __isnull=True if Field.get_prep_value()
        converts value to None.
        """
        season = Season.objects.create(year=2012, nulled_text_field=None)
        self.assertTrue(Season.objects.filter(pk=season.pk, nulled_text_field__isnull=True))
        self.assertTrue(Season.objects.filter(pk=season.pk, nulled_text_field=''))

    def test_pattern_lookups_with_substr(self):
        a = Author.objects.create(name='John Smith', alias='Johx')
        b = Author.objects.create(name='Rhonda Simpson', alias='sonx')
        tests = (
            ('startswith', [a]),
            ('istartswith', [a]),
            ('contains', [a, b]),
            ('icontains', [a, b]),
            ('endswith', [b]),
            ('iendswith', [b]),
        )
        for lookup, result in tests:
            with self.subTest(lookup=lookup):
                authors = Author.objects.filter(**{'name__%s' % lookup: Substr('alias', 1, 3)})
                self.assertCountEqual(authors, result)

    def test_custom_lookup_none_rhs(self):
        """Lookup.can_use_none_as_rhs=True allows None as a lookup value."""
        season = Season.objects.create(year=2012, nulled_text_field=None)
        query = Season.objects.get_queryset().query
        field = query.model._meta.get_field('nulled_text_field')
        self.assertIsInstance(query.build_lookup(['isnull_none_rhs'], field, None), IsNullWithNoneAsRHS)
        self.assertTrue(Season.objects.filter(pk=season.pk, nulled_text_field__isnull_none_rhs=True))

    def test_exact_exists(self):
        qs = Article.objects.filter(pk=OuterRef('pk'))
        seasons = Season.objects.annotate(
            pk_exists=Exists(qs),
        ).filter(
            pk_exists=Exists(qs),
        )
        self.assertCountEqual(seasons, Season.objects.all())

    def test_nested_outerref_lhs(self):
        tag = Tag.objects.create(name=self.au1.alias)
        tag.articles.add(self.a1)
        qs = Tag.objects.annotate(
            has_author_alias_match=Exists(
                Article.objects.annotate(
                    author_exists=Exists(
                        Author.objects.filter(alias=OuterRef(OuterRef('name')))
                    ),
                ).filter(author_exists=True)
            ),
        )
        self.assertEqual(qs.get(has_author_alias_match=True), tag)

    def test_exact_query_rhs_with_selected_columns(self):
        newest_author = Author.objects.create(name='Author 2')
        authors_max_ids = Author.objects.filter(
            name='Author 2',
        ).values(
            'name',
        ).annotate(
            max_id=Max('id'),
        ).values('max_id')
        authors = Author.objects.filter(id=authors_max_ids[:1])
        self.assertEqual(authors.get(), newest_author)

    def test_isnull_non_boolean_value(self):
        msg = 'The QuerySet value for an isnull lookup must be True or False.'
        tests = [
            Author.objects.filter(alias__isnull=1),
            Article.objects.filter(author__isnull=1),
            Season.objects.filter(games__isnull=1),
            Freebie.objects.filter(stock__isnull=1),
        ]
        for qs in tests:
            with self.subTest(qs=qs):
                with self.assertRaisesMessage(ValueError, msg):
                    qs.exists()

    def test_lookup_rhs(self):
        product = Product.objects.create(name='GME', qty_target=5000)
        stock_1 = Stock.objects.create(product=product, short=True, qty_available=180)
        stock_2 = Stock.objects.create(product=product, short=False, qty_available=5100)
        Stock.objects.create(product=product, short=False, qty_available=4000)
        self.assertCountEqual(
            Stock.objects.filter(short=Q(qty_available__lt=F('product__qty_target'))),
            [stock_1, stock_2],
        )
        self.assertCountEqual(
            Stock.objects.filter(short=ExpressionWrapper(
                Q(qty_available__lt=F('product__qty_target')),
                output_field=BooleanField(),
            )),
            [stock_1, stock_2],
        )


class LookupQueryingTests(TestCase):
    @classmethod
    def setUpTestData(cls):
        cls.s1 = Season.objects.create(year=1942, gt=1942)
        cls.s2 = Season.objects.create(year=1842, gt=1942)
        cls.s3 = Season.objects.create(year=2042, gt=1942)

    def test_annotate(self):
        qs = Season.objects.annotate(equal=Exact(F('year'), 1942))
        self.assertCountEqual(
            qs.values_list('year', 'equal'),
            ((1942, True), (1842, False), (2042, False)),
        )

    def test_alias(self):
        qs = Season.objects.alias(greater=GreaterThan(F('year'), 1910))
        self.assertCountEqual(qs.filter(greater=True), [self.s1, self.s3])

    def test_annotate_value_greater_than_value(self):
        qs = Season.objects.annotate(greater=GreaterThan(Value(40), Value(30)))
        self.assertCountEqual(
            qs.values_list('year', 'greater'),
            ((1942, True), (1842, True), (2042, True)),
        )

    def test_annotate_field_greater_than_field(self):
        qs = Season.objects.annotate(greater=GreaterThan(F('year'), F('gt')))
        self.assertCountEqual(
            qs.values_list('year', 'greater'),
            ((1942, False), (1842, False), (2042, True)),
        )

    def test_annotate_field_greater_than_value(self):
        qs = Season.objects.annotate(greater=GreaterThan(F('year'), Value(1930)))
        self.assertCountEqual(
            qs.values_list('year', 'greater'),
            ((1942, True), (1842, False), (2042, True)),
        )

    def test_annotate_field_greater_than_literal(self):
        qs = Season.objects.annotate(greater=GreaterThan(F('year'), 1930))
        self.assertCountEqual(
            qs.values_list('year', 'greater'),
            ((1942, True), (1842, False), (2042, True)),
        )

    def test_annotate_literal_greater_than_field(self):
        qs = Season.objects.annotate(greater=GreaterThan(1930, F('year')))
        self.assertCountEqual(
            qs.values_list('year', 'greater'),
            ((1942, False), (1842, True), (2042, False)),
        )

    def test_annotate_less_than_float(self):
        qs = Season.objects.annotate(lesser=LessThan(F('year'), 1942.1))
        self.assertCountEqual(
            qs.values_list('year', 'lesser'),
            ((1942, True), (1842, True), (2042, False)),
        )

    def test_annotate_greater_than_or_equal(self):
        qs = Season.objects.annotate(greater=GreaterThanOrEqual(F('year'), 1942))
        self.assertCountEqual(
            qs.values_list('year', 'greater'),
            ((1942, True), (1842, False), (2042, True)),
        )

    def test_annotate_greater_than_or_equal_float(self):
        qs = Season.objects.annotate(greater=GreaterThanOrEqual(F('year'), 1942.1))
        self.assertCountEqual(
            qs.values_list('year', 'greater'),
            ((1942, False), (1842, False), (2042, True)),
        )

    def test_combined_lookups(self):
        expression = Exact(F('year'), 1942) | GreaterThan(F('year'), 1942)
        qs = Season.objects.annotate(gte=expression)
        self.assertCountEqual(
            qs.values_list('year', 'gte'),
            ((1942, True), (1842, False), (2042, True)),
        )

    def test_lookup_in_filter(self):
        qs = Season.objects.filter(GreaterThan(F('year'), 1910))
        self.assertCountEqual(qs, [self.s1, self.s3])

    def test_filter_lookup_lhs(self):
        qs = Season.objects.annotate(before_20=LessThan(F('year'), 2000)).filter(
            before_20=LessThan(F('year'), 1900),
        )
        self.assertCountEqual(qs, [self.s2, self.s3])

    def test_filter_wrapped_lookup_lhs(self):
        qs = Season.objects.annotate(before_20=ExpressionWrapper(
            Q(year__lt=2000),
            output_field=BooleanField(),
        )).filter(before_20=LessThan(F('year'), 1900)).values_list('year', flat=True)
        self.assertCountEqual(qs, [1842, 2042])

    def test_filter_exists_lhs(self):
        qs = Season.objects.annotate(before_20=Exists(
            Season.objects.filter(pk=OuterRef('pk'), year__lt=2000),
        )).filter(before_20=LessThan(F('year'), 1900))
        self.assertCountEqual(qs, [self.s2, self.s3])

    def test_filter_subquery_lhs(self):
        qs = Season.objects.annotate(before_20=Subquery(
            Season.objects.filter(pk=OuterRef('pk')).values(
                lesser=LessThan(F('year'), 2000),
            ),
        )).filter(before_20=LessThan(F('year'), 1900))
        self.assertCountEqual(qs, [self.s2, self.s3])

    def test_combined_lookups_in_filter(self):
        expression = Exact(F('year'), 1942) | GreaterThan(F('year'), 1942)
        qs = Season.objects.filter(expression)
        self.assertCountEqual(qs, [self.s1, self.s3])

    def test_combined_annotated_lookups_in_filter(self):
        expression = Exact(F('year'), 1942) | GreaterThan(F('year'), 1942)
        qs = Season.objects.annotate(gte=expression).filter(gte=True)
        self.assertCountEqual(qs, [self.s1, self.s3])

    def test_combined_annotated_lookups_in_filter_false(self):
        expression = Exact(F('year'), 1942) | GreaterThan(F('year'), 1942)
        qs = Season.objects.annotate(gte=expression).filter(gte=False)
        self.assertSequenceEqual(qs, [self.s2])

    def test_lookup_in_order_by(self):
        qs = Season.objects.order_by(LessThan(F('year'), 1910), F('year'))
        self.assertSequenceEqual(qs, [self.s1, self.s3, self.s2])

    @skipUnlessDBFeature('supports_boolean_expr_in_select_clause')
    def test_aggregate_combined_lookup(self):
        expression = Cast(GreaterThan(F('year'), 1900), models.IntegerField())
        qs = Season.objects.aggregate(modern=models.Sum(expression))
        self.assertEqual(qs['modern'], 2)

    def test_conditional_expression(self):
        qs = Season.objects.annotate(century=Case(
            When(
                GreaterThan(F('year'), 1900) & LessThanOrEqual(F('year'), 2000),
                then=Value('20th'),
            ),
            default=Value('other'),
        )).values('year', 'century')
        self.assertCountEqual(qs, [
            {'year': 1942, 'century': '20th'},
            {'year': 1842, 'century': 'other'},
            {'year': 2042, 'century': 'other'},
        ])
