parts/django/tests/regressiontests/queries/tests.py
changeset 69 c6bca38c1cbf
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/tests/regressiontests/queries/tests.py	Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,1586 @@
+import datetime
+import pickle
+import sys
+import unittest
+
+from django.conf import settings
+from django.core.exceptions import FieldError
+from django.db import DatabaseError, connection, connections, DEFAULT_DB_ALIAS
+from django.db.models import Count
+from django.db.models.query import Q, ITER_CHUNK_SIZE, EmptyQuerySet
+from django.test import TestCase
+from django.utils.datastructures import SortedDict
+
+from models import (Annotation, Article, Author, Celebrity, Child, Cover, Detail,
+    DumbCategory, ExtraInfo, Fan, Item, LeafA, LoopX, LoopZ, ManagedModel,
+    Member, NamedCategory, Note, Number, Plaything, PointerA, Ranking, Related,
+    Report, ReservedName, Tag, TvChef, Valid, X)
+
+
+class BaseQuerysetTest(TestCase):
+    def assertValueQuerysetEqual(self, qs, values):
+        return self.assertQuerysetEqual(qs, values, transform=lambda x: x)
+
+    def assertRaisesMessage(self, exc, msg, func, *args, **kwargs):
+        try:
+            func(*args, **kwargs)
+        except Exception, e:
+            self.assertEqual(msg, str(e))
+            self.assertTrue(isinstance(e, exc), "Expected %s, got %s" % (exc, type(e)))
+        else:
+            if hasattr(exc, '__name__'):
+                excName = exc.__name__
+            else:
+                excName = str(exc)
+            raise AssertionError, "%s not raised" % excName
+
+
+class Queries1Tests(BaseQuerysetTest):
+    def setUp(self):
+        generic = NamedCategory.objects.create(name="Generic")
+        self.t1 = Tag.objects.create(name='t1', category=generic)
+        self.t2 = Tag.objects.create(name='t2', parent=self.t1, category=generic)
+        self.t3 = Tag.objects.create(name='t3', parent=self.t1)
+        t4 = Tag.objects.create(name='t4', parent=self.t3)
+        self.t5 = Tag.objects.create(name='t5', parent=self.t3)
+
+        self.n1 = Note.objects.create(note='n1', misc='foo', id=1)
+        n2 = Note.objects.create(note='n2', misc='bar', id=2)
+        self.n3 = Note.objects.create(note='n3', misc='foo', id=3)
+
+        ann1 = Annotation.objects.create(name='a1', tag=self.t1)
+        ann1.notes.add(self.n1)
+        ann2 = Annotation.objects.create(name='a2', tag=t4)
+        ann2.notes.add(n2, self.n3)
+
+        # Create these out of order so that sorting by 'id' will be different to sorting
+        # by 'info'. Helps detect some problems later.
+        self.e2 = ExtraInfo.objects.create(info='e2', note=n2)
+        e1 = ExtraInfo.objects.create(info='e1', note=self.n1)
+
+        self.a1 = Author.objects.create(name='a1', num=1001, extra=e1)
+        self.a2 = Author.objects.create(name='a2', num=2002, extra=e1)
+        a3 = Author.objects.create(name='a3', num=3003, extra=self.e2)
+        self.a4 = Author.objects.create(name='a4', num=4004, extra=self.e2)
+
+        self.time1 = datetime.datetime(2007, 12, 19, 22, 25, 0)
+        self.time2 = datetime.datetime(2007, 12, 19, 21, 0, 0)
+        time3 = datetime.datetime(2007, 12, 20, 22, 25, 0)
+        time4 = datetime.datetime(2007, 12, 20, 21, 0, 0)
+        self.i1 = Item.objects.create(name='one', created=self.time1, modified=self.time1, creator=self.a1, note=self.n3)
+        self.i1.tags = [self.t1, self.t2]
+        self.i2 = Item.objects.create(name='two', created=self.time2, creator=self.a2, note=n2)
+        self.i2.tags = [self.t1, self.t3]
+        self.i3 = Item.objects.create(name='three', created=time3, creator=self.a2, note=self.n3)
+        i4 = Item.objects.create(name='four', created=time4, creator=self.a4, note=self.n3)
+        i4.tags = [t4]
+
+        self.r1 = Report.objects.create(name='r1', creator=self.a1)
+        Report.objects.create(name='r2', creator=a3)
+        Report.objects.create(name='r3')
+
+        # Ordering by 'rank' gives us rank2, rank1, rank3. Ordering by the Meta.ordering
+        # will be rank3, rank2, rank1.
+        self.rank1 = Ranking.objects.create(rank=2, author=self.a2)
+
+        Cover.objects.create(title="first", item=i4)
+        Cover.objects.create(title="second", item=self.i2)
+
+    def test_ticket1050(self):
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__isnull=True),
+            ['<Item: three>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__id__isnull=True),
+            ['<Item: three>']
+        )
+
+    def test_ticket1801(self):
+        self.assertQuerysetEqual(
+            Author.objects.filter(item=self.i2),
+            ['<Author: a2>']
+        )
+        self.assertQuerysetEqual(
+            Author.objects.filter(item=self.i3),
+            ['<Author: a2>']
+        )
+        self.assertQuerysetEqual(
+            Author.objects.filter(item=self.i2) & Author.objects.filter(item=self.i3),
+            ['<Author: a2>']
+        )
+
+    def test_ticket2306(self):
+        # Checking that no join types are "left outer" joins.
+        query = Item.objects.filter(tags=self.t2).query
+        self.assertTrue(query.LOUTER not in [x[2] for x in query.alias_map.values()])
+
+        self.assertQuerysetEqual(
+            Item.objects.filter(Q(tags=self.t1)).order_by('name'),
+            ['<Item: one>', '<Item: two>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(Q(tags=self.t1)).filter(Q(tags=self.t2)),
+            ['<Item: one>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(Q(tags=self.t1)).filter(Q(creator__name='fred')|Q(tags=self.t2)),
+            ['<Item: one>']
+        )
+
+        # Each filter call is processed "at once" against a single table, so this is
+        # different from the previous example as it tries to find tags that are two
+        # things at once (rather than two tags).
+        self.assertQuerysetEqual(
+            Item.objects.filter(Q(tags=self.t1) & Q(tags=self.t2)),
+            []
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(Q(tags=self.t1), Q(creator__name='fred')|Q(tags=self.t2)),
+            []
+        )
+
+        qs = Author.objects.filter(ranking__rank=2, ranking__id=self.rank1.id)
+        self.assertQuerysetEqual(list(qs), ['<Author: a2>'])
+        self.assertEqual(2, qs.query.count_active_tables(), 2)
+        qs = Author.objects.filter(ranking__rank=2).filter(ranking__id=self.rank1.id)
+        self.assertEqual(qs.query.count_active_tables(), 3)
+
+    def test_ticket4464(self):
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags=self.t1).filter(tags=self.t2),
+            ['<Item: one>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__in=[self.t1, self.t2]).distinct().order_by('name'),
+            ['<Item: one>', '<Item: two>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__in=[self.t1, self.t2]).filter(tags=self.t3),
+            ['<Item: two>']
+        )
+
+        # Make sure .distinct() works with slicing (this was broken in Oracle).
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__in=[self.t1, self.t2]).order_by('name')[:3],
+            ['<Item: one>', '<Item: one>', '<Item: two>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__in=[self.t1, self.t2]).distinct().order_by('name')[:3],
+            ['<Item: one>', '<Item: two>']
+        )
+
+    def test_tickets_2080_3592(self):
+        self.assertQuerysetEqual(
+            Author.objects.filter(item__name='one') | Author.objects.filter(name='a3'),
+            ['<Author: a1>', '<Author: a3>']
+        )
+        self.assertQuerysetEqual(
+            Author.objects.filter(Q(item__name='one') | Q(name='a3')),
+            ['<Author: a1>', '<Author: a3>']
+        )
+        self.assertQuerysetEqual(
+            Author.objects.filter(Q(name='a3') | Q(item__name='one')),
+            ['<Author: a1>', '<Author: a3>']
+        )
+        self.assertQuerysetEqual(
+            Author.objects.filter(Q(item__name='three') | Q(report__name='r3')),
+            ['<Author: a2>']
+        )
+
+    def test_ticket6074(self):
+        # Merging two empty result sets shouldn't leave a queryset with no constraints
+        # (which would match everything).
+        self.assertQuerysetEqual(Author.objects.filter(Q(id__in=[])), [])
+        self.assertQuerysetEqual(
+            Author.objects.filter(Q(id__in=[])|Q(id__in=[])),
+            []
+        )
+
+    def test_tickets_1878_2939(self):
+        self.assertEqual(Item.objects.values('creator').distinct().count(), 3)
+
+        # Create something with a duplicate 'name' so that we can test multi-column
+        # cases (which require some tricky SQL transformations under the covers).
+        xx = Item(name='four', created=self.time1, creator=self.a2, note=self.n1)
+        xx.save()
+        self.assertEqual(
+            Item.objects.exclude(name='two').values('creator', 'name').distinct().count(),
+            4
+        )
+        self.assertEqual(
+            Item.objects.exclude(name='two').extra(select={'foo': '%s'}, select_params=(1,)).values('creator', 'name', 'foo').distinct().count(),
+            4
+        )
+        self.assertEqual(
+            Item.objects.exclude(name='two').extra(select={'foo': '%s'}, select_params=(1,)).values('creator', 'name').distinct().count(),
+            4
+        )
+        xx.delete()
+
+    def test_ticket7323(self):
+        self.assertEqual(Item.objects.values('creator', 'name').count(), 4)
+
+    def test_ticket2253(self):
+        q1 = Item.objects.order_by('name')
+        q2 = Item.objects.filter(id=self.i1.id)
+        self.assertQuerysetEqual(
+            q1,
+            ['<Item: four>', '<Item: one>', '<Item: three>', '<Item: two>']
+        )
+        self.assertQuerysetEqual(q2, ['<Item: one>'])
+        self.assertQuerysetEqual(
+            (q1 | q2).order_by('name'),
+            ['<Item: four>', '<Item: one>', '<Item: three>', '<Item: two>']
+        )
+        self.assertQuerysetEqual((q1 & q2).order_by('name'), ['<Item: one>'])
+
+        # FIXME: This is difficult to fix and very much an edge case, so punt for now.
+        # This is related to the order_by() tests, below, but the old bug exhibited
+        # itself here (q2 was pulling too many tables into the combined query with the
+        # new ordering, but only because we have evaluated q2 already).
+        #
+        #self.assertEqual(len((q1 & q2).order_by('name').query.tables), 1)
+
+        q1 = Item.objects.filter(tags=self.t1)
+        q2 = Item.objects.filter(note=self.n3, tags=self.t2)
+        q3 = Item.objects.filter(creator=self.a4)
+        self.assertQuerysetEqual(
+            ((q1 & q2) | q3).order_by('name'),
+            ['<Item: four>', '<Item: one>']
+        )
+
+    def test_tickets_4088_4306(self):
+        self.assertQuerysetEqual(
+            Report.objects.filter(creator=1001),
+            ['<Report: r1>']
+        )
+        self.assertQuerysetEqual(
+            Report.objects.filter(creator__num=1001),
+            ['<Report: r1>']
+        )
+        self.assertQuerysetEqual(Report.objects.filter(creator__id=1001), [])
+        self.assertQuerysetEqual(
+            Report.objects.filter(creator__id=self.a1.id),
+            ['<Report: r1>']
+        )
+        self.assertQuerysetEqual(
+            Report.objects.filter(creator__name='a1'),
+            ['<Report: r1>']
+        )
+
+    def test_ticket4510(self):
+        self.assertQuerysetEqual(
+            Author.objects.filter(report__name='r1'),
+            ['<Author: a1>']
+        )
+
+    def test_ticket7378(self):
+        self.assertQuerysetEqual(self.a1.report_set.all(), ['<Report: r1>'])
+
+    def test_tickets_5324_6704(self):
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__name='t4'),
+            ['<Item: four>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.exclude(tags__name='t4').order_by('name').distinct(),
+            ['<Item: one>', '<Item: three>', '<Item: two>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.exclude(tags__name='t4').order_by('name').distinct().reverse(),
+            ['<Item: two>', '<Item: three>', '<Item: one>']
+        )
+        self.assertQuerysetEqual(
+            Author.objects.exclude(item__name='one').distinct().order_by('name'),
+            ['<Author: a2>', '<Author: a3>', '<Author: a4>']
+        )
+
+        # Excluding across a m2m relation when there is more than one related
+        # object associated was problematic.
+        self.assertQuerysetEqual(
+            Item.objects.exclude(tags__name='t1').order_by('name'),
+            ['<Item: four>', '<Item: three>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.exclude(tags__name='t1').exclude(tags__name='t4'),
+            ['<Item: three>']
+        )
+
+        # Excluding from a relation that cannot be NULL should not use outer joins.
+        query = Item.objects.exclude(creator__in=[self.a1, self.a2]).query
+        self.assertTrue(query.LOUTER not in [x[2] for x in query.alias_map.values()])
+
+        # Similarly, when one of the joins cannot possibly, ever, involve NULL
+        # values (Author -> ExtraInfo, in the following), it should never be
+        # promoted to a left outer join. So the following query should only
+        # involve one "left outer" join (Author -> Item is 0-to-many).
+        qs = Author.objects.filter(id=self.a1.id).filter(Q(extra__note=self.n1)|Q(item__note=self.n3))
+        self.assertEqual(
+            len([x[2] for x in qs.query.alias_map.values() if x[2] == query.LOUTER and qs.query.alias_refcount[x[1]]]),
+            1
+        )
+
+        # The previous changes shouldn't affect nullable foreign key joins.
+        self.assertQuerysetEqual(
+            Tag.objects.filter(parent__isnull=True).order_by('name'),
+            ['<Tag: t1>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.exclude(parent__isnull=True).order_by('name'),
+            ['<Tag: t2>', '<Tag: t3>', '<Tag: t4>', '<Tag: t5>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.exclude(Q(parent__name='t1') | Q(parent__isnull=True)).order_by('name'),
+            ['<Tag: t4>', '<Tag: t5>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.exclude(Q(parent__isnull=True) | Q(parent__name='t1')).order_by('name'),
+            ['<Tag: t4>', '<Tag: t5>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.exclude(Q(parent__parent__isnull=True)).order_by('name'),
+            ['<Tag: t4>', '<Tag: t5>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.filter(~Q(parent__parent__isnull=True)).order_by('name'),
+            ['<Tag: t4>', '<Tag: t5>']
+        )
+
+    def test_ticket2091(self):
+        t = Tag.objects.get(name='t4')
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__in=[t]),
+            ['<Item: four>']
+        )
+
+    def test_heterogeneous_qs_combination(self):
+        # Combining querysets built on different models should behave in a well-defined
+        # fashion. We raise an error.
+        self.assertRaisesMessage(
+            AssertionError,
+            'Cannot combine queries on two different base models.',
+            lambda: Author.objects.all() & Tag.objects.all()
+        )
+        self.assertRaisesMessage(
+            AssertionError,
+            'Cannot combine queries on two different base models.',
+            lambda: Author.objects.all() | Tag.objects.all()
+        )
+
+    def test_ticket3141(self):
+        self.assertEqual(Author.objects.extra(select={'foo': '1'}).count(), 4)
+        self.assertEqual(
+            Author.objects.extra(select={'foo': '%s'}, select_params=(1,)).count(),
+            4
+        )
+
+    def test_ticket2400(self):
+        self.assertQuerysetEqual(
+            Author.objects.filter(item__isnull=True),
+            ['<Author: a3>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.filter(item__isnull=True),
+            ['<Tag: t5>']
+        )
+
+    def test_ticket2496(self):
+        self.assertQuerysetEqual(
+            Item.objects.extra(tables=['queries_author']).select_related().order_by('name')[:1],
+            ['<Item: four>']
+        )
+
+    def test_tickets_2076_7256(self):
+        # Ordering on related tables should be possible, even if the table is
+        # not otherwise involved.
+        self.assertQuerysetEqual(
+            Item.objects.order_by('note__note', 'name'),
+            ['<Item: two>', '<Item: four>', '<Item: one>', '<Item: three>']
+        )
+
+        # Ordering on a related field should use the remote model's default
+        # ordering as a final step.
+        self.assertQuerysetEqual(
+            Author.objects.order_by('extra', '-name'),
+            ['<Author: a2>', '<Author: a1>', '<Author: a4>', '<Author: a3>']
+        )
+
+        # Using remote model default ordering can span multiple models (in this
+        # case, Cover is ordered by Item's default, which uses Note's default).
+        self.assertQuerysetEqual(
+            Cover.objects.all(),
+            ['<Cover: first>', '<Cover: second>']
+        )
+
+        # If the remote model does not have a default ordering, we order by its 'id'
+        # field.
+        self.assertQuerysetEqual(
+            Item.objects.order_by('creator', 'name'),
+            ['<Item: one>', '<Item: three>', '<Item: two>', '<Item: four>']
+        )
+
+        # Ordering by a many-valued attribute (e.g. a many-to-many or reverse
+        # ForeignKey) is legal, but the results might not make sense. That
+        # isn't Django's problem. Garbage in, garbage out.
+        self.assertQuerysetEqual(
+            Item.objects.filter(tags__isnull=False).order_by('tags', 'id'),
+            ['<Item: one>', '<Item: two>', '<Item: one>', '<Item: two>', '<Item: four>']
+        )
+
+        # If we replace the default ordering, Django adjusts the required
+        # tables automatically. Item normally requires a join with Note to do
+        # the default ordering, but that isn't needed here.
+        qs = Item.objects.order_by('name')
+        self.assertQuerysetEqual(
+            qs,
+            ['<Item: four>', '<Item: one>', '<Item: three>', '<Item: two>']
+        )
+        self.assertEqual(len(qs.query.tables), 1)
+
+    def test_tickets_2874_3002(self):
+        qs = Item.objects.select_related().order_by('note__note', 'name')
+        self.assertQuerysetEqual(
+            qs,
+            ['<Item: two>', '<Item: four>', '<Item: one>', '<Item: three>']
+        )
+
+        # This is also a good select_related() test because there are multiple
+        # Note entries in the SQL. The two Note items should be different.
+        self.assertTrue(repr(qs[0].note), '<Note: n2>')
+        self.assertEqual(repr(qs[0].creator.extra.note), '<Note: n1>')
+
+    def test_ticket3037(self):
+        self.assertQuerysetEqual(
+            Item.objects.filter(Q(creator__name='a3', name='two')|Q(creator__name='a4', name='four')),
+            ['<Item: four>']
+        )
+
+    def test_tickets_5321_7070(self):
+        # Ordering columns must be included in the output columns. Note that
+        # this means results that might otherwise be distinct are not (if there
+        # are multiple values in the ordering cols), as in this example. This
+        # isn't a bug; it's a warning to be careful with the selection of
+        # ordering columns.
+        self.assertValueQuerysetEqual(
+            Note.objects.values('misc').distinct().order_by('note', '-misc'),
+            [{'misc': u'foo'}, {'misc': u'bar'}, {'misc': u'foo'}]
+        )
+
+    def test_ticket4358(self):
+        # If you don't pass any fields to values(), relation fields are
+        # returned as "foo_id" keys, not "foo". For consistency, you should be
+        # able to pass "foo_id" in the fields list and have it work, too. We
+        # actually allow both "foo" and "foo_id".
+
+        # The *_id version is returned by default.
+        self.assertTrue('note_id' in ExtraInfo.objects.values()[0])
+
+        # You can also pass it in explicitly.
+        self.assertValueQuerysetEqual(
+            ExtraInfo.objects.values('note_id'),
+            [{'note_id': 1}, {'note_id': 2}]
+        )
+
+        # ...or use the field name.
+        self.assertValueQuerysetEqual(
+            ExtraInfo.objects.values('note'),
+            [{'note': 1}, {'note': 2}]
+        )
+
+    def test_ticket2902(self):
+        # Parameters can be given to extra_select, *if* you use a SortedDict.
+
+        # (First we need to know which order the keys fall in "naturally" on
+        # your system, so we can put things in the wrong way around from
+        # normal. A normal dict would thus fail.)
+        s = [('a', '%s'), ('b', '%s')]
+        params = ['one', 'two']
+        if {'a': 1, 'b': 2}.keys() == ['a', 'b']:
+            s.reverse()
+            params.reverse()
+
+        # This slightly odd comparison works around the fact that PostgreSQL will
+        # return 'one' and 'two' as strings, not Unicode objects. It's a side-effect of
+        # using constants here and not a real concern.
+        d = Item.objects.extra(select=SortedDict(s), select_params=params).values('a', 'b')[0]
+        self.assertEqual(d, {'a': u'one', 'b': u'two'})
+
+        # Order by the number of tags attached to an item.
+        l = Item.objects.extra(select={'count': 'select count(*) from queries_item_tags where queries_item_tags.item_id = queries_item.id'}).order_by('-count')
+        self.assertEqual([o.count for o in l], [2, 2, 1, 0])
+
+    def test_ticket6154(self):
+        # Multiple filter statements are joined using "AND" all the time.
+
+        self.assertQuerysetEqual(
+            Author.objects.filter(id=self.a1.id).filter(Q(extra__note=self.n1)|Q(item__note=self.n3)),
+            ['<Author: a1>']
+        )
+        self.assertQuerysetEqual(
+                Author.objects.filter(Q(extra__note=self.n1)|Q(item__note=self.n3)).filter(id=self.a1.id),
+            ['<Author: a1>']
+        )
+
+    def test_ticket6981(self):
+        self.assertQuerysetEqual(
+            Tag.objects.select_related('parent').order_by('name'),
+            ['<Tag: t1>', '<Tag: t2>', '<Tag: t3>', '<Tag: t4>', '<Tag: t5>']
+        )
+
+    def test_ticket9926(self):
+        self.assertQuerysetEqual(
+            Tag.objects.select_related("parent", "category").order_by('name'),
+            ['<Tag: t1>', '<Tag: t2>', '<Tag: t3>', '<Tag: t4>', '<Tag: t5>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.select_related('parent', "parent__category").order_by('name'),
+            ['<Tag: t1>', '<Tag: t2>', '<Tag: t3>', '<Tag: t4>', '<Tag: t5>']
+        )
+
+    def test_tickets_6180_6203(self):
+        # Dates with limits and/or counts
+        self.assertEqual(Item.objects.count(), 4)
+        self.assertEqual(Item.objects.dates('created', 'month').count(), 1)
+        self.assertEqual(Item.objects.dates('created', 'day').count(), 2)
+        self.assertEqual(len(Item.objects.dates('created', 'day')), 2)
+        self.assertEqual(Item.objects.dates('created', 'day')[0], datetime.datetime(2007, 12, 19, 0, 0))
+
+    def test_tickets_7087_12242(self):
+        # Dates with extra select columns
+        self.assertQuerysetEqual(
+            Item.objects.dates('created', 'day').extra(select={'a': 1}),
+            ['datetime.datetime(2007, 12, 19, 0, 0)', 'datetime.datetime(2007, 12, 20, 0, 0)']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.extra(select={'a': 1}).dates('created', 'day'),
+            ['datetime.datetime(2007, 12, 19, 0, 0)', 'datetime.datetime(2007, 12, 20, 0, 0)']
+        )
+
+        name="one"
+        self.assertQuerysetEqual(
+            Item.objects.dates('created', 'day').extra(where=['name=%s'], params=[name]),
+            ['datetime.datetime(2007, 12, 19, 0, 0)']
+        )
+
+        self.assertQuerysetEqual(
+            Item.objects.extra(where=['name=%s'], params=[name]).dates('created', 'day'),
+            ['datetime.datetime(2007, 12, 19, 0, 0)']
+        )
+
+    def test_ticket7155(self):
+        # Nullable dates
+        self.assertQuerysetEqual(
+            Item.objects.dates('modified', 'day'),
+            ['datetime.datetime(2007, 12, 19, 0, 0)']
+        )
+
+    def test_ticket7098(self):
+        # Make sure semi-deprecated ordering by related models syntax still
+        # works.
+        self.assertValueQuerysetEqual(
+            Item.objects.values('note__note').order_by('queries_note.note', 'id'),
+            [{'note__note': u'n2'}, {'note__note': u'n3'}, {'note__note': u'n3'}, {'note__note': u'n3'}]
+        )
+
+    def test_ticket7096(self):
+        # Make sure exclude() with multiple conditions continues to work.
+        self.assertQuerysetEqual(
+            Tag.objects.filter(parent=self.t1, name='t3').order_by('name'),
+            ['<Tag: t3>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.exclude(parent=self.t1, name='t3').order_by('name'),
+            ['<Tag: t1>', '<Tag: t2>', '<Tag: t4>', '<Tag: t5>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.exclude(tags__name='t1', name='one').order_by('name').distinct(),
+            ['<Item: four>', '<Item: three>', '<Item: two>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(name__in=['three', 'four']).exclude(tags__name='t1').order_by('name'),
+            ['<Item: four>', '<Item: three>']
+        )
+
+        # More twisted cases, involving nested negations.
+        self.assertQuerysetEqual(
+            Item.objects.exclude(~Q(tags__name='t1', name='one')),
+            ['<Item: one>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(~Q(tags__name='t1', name='one'), name='two'),
+            ['<Item: two>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.exclude(~Q(tags__name='t1', name='one'), name='two'),
+            ['<Item: four>', '<Item: one>', '<Item: three>']
+        )
+
+    def test_tickets_7204_7506(self):
+        # Make sure querysets with related fields can be pickled. If this
+        # doesn't crash, it's a Good Thing.
+        pickle.dumps(Item.objects.all())
+
+    def test_ticket7813(self):
+        # We should also be able to pickle things that use select_related().
+        # The only tricky thing here is to ensure that we do the related
+        # selections properly after unpickling.
+        qs = Item.objects.select_related()
+        query = qs.query.get_compiler(qs.db).as_sql()[0]
+        query2 = pickle.loads(pickle.dumps(qs.query))
+        self.assertEqual(
+            query2.get_compiler(qs.db).as_sql()[0],
+            query
+        )
+
+    def test_deferred_load_qs_pickling(self):
+        # Check pickling of deferred-loading querysets
+        qs = Item.objects.defer('name', 'creator')
+        q2 = pickle.loads(pickle.dumps(qs))
+        self.assertEqual(list(qs), list(q2))
+        q3 = pickle.loads(pickle.dumps(qs, pickle.HIGHEST_PROTOCOL))
+        self.assertEqual(list(qs), list(q3))
+
+    def test_ticket7277(self):
+        self.assertQuerysetEqual(
+            self.n1.annotation_set.filter(Q(tag=self.t5) | Q(tag__children=self.t5) | Q(tag__children__children=self.t5)),
+            ['<Annotation: a1>']
+        )
+
+    def test_tickets_7448_7707(self):
+        # Complex objects should be converted to strings before being used in
+        # lookups.
+        self.assertQuerysetEqual(
+            Item.objects.filter(created__in=[self.time1, self.time2]),
+            ['<Item: one>', '<Item: two>']
+        )
+
+    def test_ticket7235(self):
+        # An EmptyQuerySet should not raise exceptions if it is filtered.
+        q = EmptyQuerySet()
+        self.assertQuerysetEqual(q.all(), [])
+        self.assertQuerysetEqual(q.filter(x=10), [])
+        self.assertQuerysetEqual(q.exclude(y=3), [])
+        self.assertQuerysetEqual(q.complex_filter({'pk': 1}), [])
+        self.assertQuerysetEqual(q.select_related('spam', 'eggs'), [])
+        self.assertQuerysetEqual(q.annotate(Count('eggs')), [])
+        self.assertQuerysetEqual(q.order_by('-pub_date', 'headline'), [])
+        self.assertQuerysetEqual(q.distinct(), [])
+        self.assertQuerysetEqual(
+            q.extra(select={'is_recent': "pub_date > '2006-01-01'"}),
+            []
+        )
+        q.query.low_mark = 1
+        self.assertRaisesMessage(
+            AssertionError,
+            'Cannot change a query once a slice has been taken',
+            q.extra, select={'is_recent': "pub_date > '2006-01-01'"}
+        )
+        self.assertQuerysetEqual(q.reverse(), [])
+        self.assertQuerysetEqual(q.defer('spam', 'eggs'), [])
+        self.assertQuerysetEqual(q.only('spam', 'eggs'), [])
+
+    def test_ticket7791(self):
+        # There were "issues" when ordering and distinct-ing on fields related
+        # via ForeignKeys.
+        self.assertEqual(
+            len(Note.objects.order_by('extrainfo__info').distinct()),
+            3
+        )
+
+        # Pickling of DateQuerySets used to fail
+        qs = Item.objects.dates('created', 'month')
+        _ = pickle.loads(pickle.dumps(qs))
+
+    def test_ticket9997(self):
+        # If a ValuesList or Values queryset is passed as an inner query, we
+        # make sure it's only requesting a single value and use that as the
+        # thing to select.
+        self.assertQuerysetEqual(
+            Tag.objects.filter(name__in=Tag.objects.filter(parent=self.t1).values('name')),
+            ['<Tag: t2>', '<Tag: t3>']
+        )
+
+        # Multi-valued values() and values_list() querysets should raise errors.
+        self.assertRaisesMessage(
+            TypeError,
+            'Cannot use a multi-field ValuesQuerySet as a filter value.',
+            lambda: Tag.objects.filter(name__in=Tag.objects.filter(parent=self.t1).values('name', 'id'))
+        )
+        self.assertRaisesMessage(
+            TypeError,
+            'Cannot use a multi-field ValuesListQuerySet as a filter value.',
+            lambda: Tag.objects.filter(name__in=Tag.objects.filter(parent=self.t1).values_list('name', 'id'))
+        )
+
+    def test_ticket9985(self):
+        # qs.values_list(...).values(...) combinations should work.
+        self.assertValueQuerysetEqual(
+            Note.objects.values_list("note", flat=True).values("id").order_by("id"),
+            [{'id': 1}, {'id': 2}, {'id': 3}]
+        )
+        self.assertQuerysetEqual(
+            Annotation.objects.filter(notes__in=Note.objects.filter(note="n1").values_list('note').values('id')),
+            ['<Annotation: a1>']
+        )
+
+    def test_ticket10205(self):
+        # When bailing out early because of an empty "__in" filter, we need
+        # to set things up correctly internally so that subqueries can continue properly.
+        self.assertEqual(Tag.objects.filter(name__in=()).update(name="foo"), 0)
+
+    def test_ticket10432(self):
+        # Testing an empty "__in" filter with a generator as the value.
+        def f():
+            return iter([])
+        n_obj = Note.objects.all()[0]
+        def g():
+            for i in [n_obj.pk]:
+                yield i
+        self.assertQuerysetEqual(Note.objects.filter(pk__in=f()), [])
+        self.assertEqual(list(Note.objects.filter(pk__in=g())), [n_obj])
+
+    def test_ticket10742(self):
+        # Queries used in an __in clause don't execute subqueries
+
+        subq = Author.objects.filter(num__lt=3000)
+        qs = Author.objects.filter(pk__in=subq)
+        self.assertQuerysetEqual(qs, ['<Author: a1>', '<Author: a2>'])
+
+        # The subquery result cache should not be populated
+        self.assertTrue(subq._result_cache is None)
+
+        subq = Author.objects.filter(num__lt=3000)
+        qs = Author.objects.exclude(pk__in=subq)
+        self.assertQuerysetEqual(qs, ['<Author: a3>', '<Author: a4>'])
+
+        # The subquery result cache should not be populated
+        self.assertTrue(subq._result_cache is None)
+
+        subq = Author.objects.filter(num__lt=3000)
+        self.assertQuerysetEqual(
+            Author.objects.filter(Q(pk__in=subq) & Q(name='a1')),
+            ['<Author: a1>']
+        )
+
+        # The subquery result cache should not be populated
+        self.assertTrue(subq._result_cache is None)
+
+    def test_ticket7076(self):
+        # Excluding shouldn't eliminate NULL entries.
+        self.assertQuerysetEqual(
+            Item.objects.exclude(modified=self.time1).order_by('name'),
+            ['<Item: four>', '<Item: three>', '<Item: two>']
+        )
+        self.assertQuerysetEqual(
+            Tag.objects.exclude(parent__name=self.t1.name),
+            ['<Tag: t1>', '<Tag: t4>', '<Tag: t5>']
+        )
+
+    def test_ticket7181(self):
+        # Ordering by related tables should accomodate nullable fields (this
+        # test is a little tricky, since NULL ordering is database dependent.
+        # Instead, we just count the number of results).
+        self.assertEqual(len(Tag.objects.order_by('parent__name')), 5)
+
+        # Empty querysets can be merged with others.
+        self.assertQuerysetEqual(
+            Note.objects.none() | Note.objects.all(),
+            ['<Note: n1>', '<Note: n2>', '<Note: n3>']
+        )
+        self.assertQuerysetEqual(
+            Note.objects.all() | Note.objects.none(),
+            ['<Note: n1>', '<Note: n2>', '<Note: n3>']
+        )
+        self.assertQuerysetEqual(Note.objects.none() & Note.objects.all(), [])
+        self.assertQuerysetEqual(Note.objects.all() & Note.objects.none(), [])
+
+    def test_ticket9411(self):
+        # Make sure bump_prefix() (an internal Query method) doesn't (re-)break. It's
+        # sufficient that this query runs without error.
+        qs = Tag.objects.values_list('id', flat=True).order_by('id')
+        qs.query.bump_prefix()
+        first = qs[0]
+        self.assertEqual(list(qs), range(first, first+5))
+
+    def test_ticket8439(self):
+        # Complex combinations of conjunctions, disjunctions and nullable
+        # relations.
+        self.assertQuerysetEqual(
+            Author.objects.filter(Q(item__note__extrainfo=self.e2)|Q(report=self.r1, name='xyz')),
+            ['<Author: a2>']
+        )
+        self.assertQuerysetEqual(
+            Author.objects.filter(Q(report=self.r1, name='xyz')|Q(item__note__extrainfo=self.e2)),
+            ['<Author: a2>']
+        )
+        self.assertQuerysetEqual(
+            Annotation.objects.filter(Q(tag__parent=self.t1)|Q(notes__note='n1', name='a1')),
+            ['<Annotation: a1>']
+        )
+        xx = ExtraInfo.objects.create(info='xx', note=self.n3)
+        self.assertQuerysetEqual(
+            Note.objects.filter(Q(extrainfo__author=self.a1)|Q(extrainfo=xx)),
+            ['<Note: n1>', '<Note: n3>']
+        )
+        xx.delete()
+        q = Note.objects.filter(Q(extrainfo__author=self.a1)|Q(extrainfo=xx)).query
+        self.assertEqual(
+            len([x[2] for x in q.alias_map.values() if x[2] == q.LOUTER and q.alias_refcount[x[1]]]),
+            1
+        )
+
+
+class Queries2Tests(TestCase):
+    def setUp(self):
+        Number.objects.create(num=4)
+        Number.objects.create(num=8)
+        Number.objects.create(num=12)
+
+    def test_ticket4289(self):
+        # A slight variation on the restricting the filtering choices by the
+        # lookup constraints.
+        self.assertQuerysetEqual(Number.objects.filter(num__lt=4), [])
+        self.assertQuerysetEqual(Number.objects.filter(num__gt=8, num__lt=12), [])
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__gt=8, num__lt=13),
+            ['<Number: 12>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(Q(num__lt=4) | Q(num__gt=8, num__lt=12)),
+            []
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(Q(num__gt=8, num__lt=12) | Q(num__lt=4)),
+            []
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(Q(num__gt=8) & Q(num__lt=12) | Q(num__lt=4)),
+            []
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(Q(num__gt=7) & Q(num__lt=12) | Q(num__lt=4)),
+            ['<Number: 8>']
+        )
+
+    def test_ticket12239(self):
+        # Float was being rounded to integer on gte queries on integer field.  Tests
+        # show that gt, lt, gte, and lte work as desired.  Note that the fix changes
+        # get_prep_lookup for gte and lt queries only.
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__gt=11.9),
+            ['<Number: 12>']
+        )
+        self.assertQuerysetEqual(Number.objects.filter(num__gt=12), [])
+        self.assertQuerysetEqual(Number.objects.filter(num__gt=12.0), [])
+        self.assertQuerysetEqual(Number.objects.filter(num__gt=12.1), [])
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__lt=12),
+            ['<Number: 4>', '<Number: 8>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__lt=12.0),
+            ['<Number: 4>', '<Number: 8>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__lt=12.1),
+            ['<Number: 4>', '<Number: 8>', '<Number: 12>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__gte=11.9),
+            ['<Number: 12>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__gte=12),
+            ['<Number: 12>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__gte=12.0),
+            ['<Number: 12>']
+        )
+        self.assertQuerysetEqual(Number.objects.filter(num__gte=12.1), [])
+        self.assertQuerysetEqual(Number.objects.filter(num__gte=12.9), [])
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__lte=11.9),
+            ['<Number: 4>', '<Number: 8>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__lte=12),
+            ['<Number: 4>', '<Number: 8>', '<Number: 12>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__lte=12.0),
+            ['<Number: 4>', '<Number: 8>', '<Number: 12>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__lte=12.1),
+            ['<Number: 4>', '<Number: 8>', '<Number: 12>']
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(num__lte=12.9),
+            ['<Number: 4>', '<Number: 8>', '<Number: 12>']
+        )
+
+    def test_ticket7411(self):
+        # Saving to db must work even with partially read result set in another
+        # cursor.
+        for num in range(2 * ITER_CHUNK_SIZE + 1):
+            _ = Number.objects.create(num=num)
+
+        for i, obj in enumerate(Number.objects.all()):
+            obj.save()
+            if i > 10: break
+
+    def test_ticket7759(self):
+        # Count should work with a partially read result set.
+        count = Number.objects.count()
+        qs = Number.objects.all()
+        def run():
+            for obj in qs:
+                return qs.count() == count
+        self.assertTrue(run())
+
+
+class Queries3Tests(BaseQuerysetTest):
+    def test_ticket7107(self):
+        # This shouldn't create an infinite loop.
+        self.assertQuerysetEqual(Valid.objects.all(), [])
+
+    def test_ticket8683(self):
+        # Raise proper error when a DateQuerySet gets passed a wrong type of
+        # field
+        self.assertRaisesMessage(
+            AssertionError,
+            "'name' isn't a DateField.",
+            Item.objects.dates, 'name', 'month'
+        )
+
+class Queries4Tests(BaseQuerysetTest):
+    def setUp(self):
+        generic = NamedCategory.objects.create(name="Generic")
+        self.t1 = Tag.objects.create(name='t1', category=generic)
+
+        n1 = Note.objects.create(note='n1', misc='foo', id=1)
+        n2 = Note.objects.create(note='n2', misc='bar', id=2)
+
+        e1 = ExtraInfo.objects.create(info='e1', note=n1)
+        e2 = ExtraInfo.objects.create(info='e2', note=n2)
+
+        a1 = Author.objects.create(name='a1', num=1001, extra=e1)
+        a3 = Author.objects.create(name='a3', num=3003, extra=e2)
+
+        Report.objects.create(name='r1', creator=a1)
+        Report.objects.create(name='r2', creator=a3)
+        Report.objects.create(name='r3')
+
+    def test_ticket7095(self):
+        # Updates that are filtered on the model being updated are somewhat
+        # tricky in MySQL. This exercises that case.
+        ManagedModel.objects.create(data='mm1', tag=self.t1, public=True)
+        self.assertEqual(ManagedModel.objects.update(data='mm'), 1)
+
+        # A values() or values_list() query across joined models must use outer
+        # joins appropriately.
+        # Note: In Oracle, we expect a null CharField to return u'' instead of
+        # None.
+        if connection.features.interprets_empty_strings_as_nulls:
+            expected_null_charfield_repr = u''
+        else:
+            expected_null_charfield_repr = None
+        self.assertValueQuerysetEqual(
+            Report.objects.values_list("creator__extra__info", flat=True).order_by("name"),
+            [u'e1', u'e2', expected_null_charfield_repr],
+        )
+
+        # Similarly for select_related(), joins beyond an initial nullable join
+        # must use outer joins so that all results are included.
+        self.assertQuerysetEqual(
+            Report.objects.select_related("creator", "creator__extra").order_by("name"),
+            ['<Report: r1>', '<Report: r2>', '<Report: r3>']
+        )
+
+        # When there are multiple paths to a table from another table, we have
+        # to be careful not to accidentally reuse an inappropriate join when
+        # using select_related(). We used to return the parent's Detail record
+        # here by mistake.
+
+        d1 = Detail.objects.create(data="d1")
+        d2 = Detail.objects.create(data="d2")
+        m1 = Member.objects.create(name="m1", details=d1)
+        m2 = Member.objects.create(name="m2", details=d2)
+        Child.objects.create(person=m2, parent=m1)
+        obj = m1.children.select_related("person__details")[0]
+        self.assertEqual(obj.person.details.data, u'd2')
+
+    def test_order_by_resetting(self):
+        # Calling order_by() with no parameters removes any existing ordering on the
+        # model. But it should still be possible to add new ordering after that.
+        qs = Author.objects.order_by().order_by('name')
+        self.assertTrue('ORDER BY' in qs.query.get_compiler(qs.db).as_sql()[0])
+
+    def test_ticket10181(self):
+        # Avoid raising an EmptyResultSet if an inner query is probably
+        # empty (and hence, not executed).
+        self.assertQuerysetEqual(
+            Tag.objects.filter(id__in=Tag.objects.filter(id__in=[])),
+            []
+        )
+
+
+class Queries5Tests(TestCase):
+    def setUp(self):
+        # Ordering by 'rank' gives us rank2, rank1, rank3. Ordering by the Meta.ordering
+        # will be rank3, rank2, rank1.
+        n1 = Note.objects.create(note='n1', misc='foo', id=1)
+        n2 = Note.objects.create(note='n2', misc='bar', id=2)
+        e1 = ExtraInfo.objects.create(info='e1', note=n1)
+        e2 = ExtraInfo.objects.create(info='e2', note=n2)
+        a1 = Author.objects.create(name='a1', num=1001, extra=e1)
+        a2 = Author.objects.create(name='a2', num=2002, extra=e1)
+        a3 = Author.objects.create(name='a3', num=3003, extra=e2)
+        self.rank1 = Ranking.objects.create(rank=2, author=a2)
+        Ranking.objects.create(rank=1, author=a3)
+        Ranking.objects.create(rank=3, author=a1)
+
+    def test_ordering(self):
+        # Cross model ordering is possible in Meta, too.
+        self.assertQuerysetEqual(
+            Ranking.objects.all(),
+            ['<Ranking: 3: a1>', '<Ranking: 2: a2>', '<Ranking: 1: a3>']
+        )
+        self.assertQuerysetEqual(
+            Ranking.objects.all().order_by('rank'),
+            ['<Ranking: 1: a3>', '<Ranking: 2: a2>', '<Ranking: 3: a1>']
+        )
+
+
+        # Ordering of extra() pieces is possible, too and you can mix extra
+        # fields and model fields in the ordering.
+        self.assertQuerysetEqual(
+            Ranking.objects.extra(tables=['django_site'], order_by=['-django_site.id', 'rank']),
+            ['<Ranking: 1: a3>', '<Ranking: 2: a2>', '<Ranking: 3: a1>']
+        )
+
+        qs = Ranking.objects.extra(select={'good': 'case when rank > 2 then 1 else 0 end'})
+        self.assertEqual(
+            [o.good for o in qs.extra(order_by=('-good',))],
+            [True, False, False]
+        )
+        self.assertQuerysetEqual(
+            qs.extra(order_by=('-good', 'id')),
+            ['<Ranking: 3: a1>', '<Ranking: 2: a2>', '<Ranking: 1: a3>']
+        )
+
+        # Despite having some extra aliases in the query, we can still omit
+        # them in a values() query.
+        dicts = qs.values('id', 'rank').order_by('id')
+        self.assertEqual(
+            [d.items()[1] for d in dicts],
+            [('rank', 2), ('rank', 1), ('rank', 3)]
+        )
+
+    def test_ticket7256(self):
+        # An empty values() call includes all aliases, including those from an
+        # extra()
+        qs = Ranking.objects.extra(select={'good': 'case when rank > 2 then 1 else 0 end'})
+        dicts = qs.values().order_by('id')
+        for d in dicts: del d['id']; del d['author_id']
+        self.assertEqual(
+            [sorted(d.items()) for d in dicts],
+            [[('good', 0), ('rank', 2)], [('good', 0), ('rank', 1)], [('good', 1), ('rank', 3)]]
+        )
+
+    def test_ticket7045(self):
+        # Extra tables used to crash SQL construction on the second use.
+        qs = Ranking.objects.extra(tables=['django_site'])
+        qs.query.get_compiler(qs.db).as_sql()
+        # test passes if this doesn't raise an exception.
+        qs.query.get_compiler(qs.db).as_sql()
+
+    def test_ticket9848(self):
+        # Make sure that updates which only filter on sub-tables don't
+        # inadvertently update the wrong records (bug #9848).
+
+        # Make sure that the IDs from different tables don't happen to match.
+        self.assertQuerysetEqual(
+            Ranking.objects.filter(author__name='a1'),
+            ['<Ranking: 3: a1>']
+        )
+        self.assertEqual(
+            Ranking.objects.filter(author__name='a1').update(rank='4'),
+            1
+        )
+        r = Ranking.objects.filter(author__name='a1')[0]
+        self.assertNotEqual(r.id, r.author.id)
+        self.assertEqual(r.rank, 4)
+        r.rank = 3
+        r.save()
+        self.assertQuerysetEqual(
+            Ranking.objects.all(),
+            ['<Ranking: 3: a1>', '<Ranking: 2: a2>', '<Ranking: 1: a3>']
+        )
+
+    def test_ticket5261(self):
+        self.assertQuerysetEqual(
+            Note.objects.exclude(Q()),
+            ['<Note: n1>', '<Note: n2>']
+        )
+
+
+class SelectRelatedTests(TestCase):
+    def test_tickets_3045_3288(self):
+        # Once upon a time, select_related() with circular relations would loop
+        # infinitely if you forgot to specify "depth". Now we set an arbitrary
+        # default upper bound.
+        self.assertQuerysetEqual(X.objects.all(), [])
+        self.assertQuerysetEqual(X.objects.select_related(), [])
+
+
+class SubclassFKTests(TestCase):
+    def test_ticket7778(self):
+        # Model subclasses could not be deleted if a nullable foreign key
+        # relates to a model that relates back.
+
+        num_celebs = Celebrity.objects.count()
+        tvc = TvChef.objects.create(name="Huey")
+        self.assertEqual(Celebrity.objects.count(), num_celebs + 1)
+        Fan.objects.create(fan_of=tvc)
+        Fan.objects.create(fan_of=tvc)
+        tvc.delete()
+
+        # The parent object should have been deleted as well.
+        self.assertEqual(Celebrity.objects.count(), num_celebs)
+
+
+class CustomPkTests(TestCase):
+    def test_ticket7371(self):
+        self.assertQuerysetEqual(Related.objects.order_by('custom'), [])
+
+
+class NullableRelOrderingTests(TestCase):
+    def test_ticket10028(self):
+        # Ordering by model related to nullable relations(!) should use outer
+        # joins, so that all results are included.
+        _ = Plaything.objects.create(name="p1")
+        self.assertQuerysetEqual(
+            Plaything.objects.all(),
+            ['<Plaything: p1>']
+        )
+
+
+class DisjunctiveFilterTests(TestCase):
+    def setUp(self):
+        self.n1 = Note.objects.create(note='n1', misc='foo', id=1)
+        ExtraInfo.objects.create(info='e1', note=self.n1)
+
+    def test_ticket7872(self):
+        # Another variation on the disjunctive filtering theme.
+
+        # For the purposes of this regression test, it's important that there is no
+        # Join object releated to the LeafA we create.
+        LeafA.objects.create(data='first')
+        self.assertQuerysetEqual(LeafA.objects.all(), ['<LeafA: first>'])
+        self.assertQuerysetEqual(
+            LeafA.objects.filter(Q(data='first')|Q(join__b__data='second')),
+            ['<LeafA: first>']
+        )
+
+    def test_ticket8283(self):
+        # Checking that applying filters after a disjunction works correctly.
+        self.assertQuerysetEqual(
+            (ExtraInfo.objects.filter(note=self.n1)|ExtraInfo.objects.filter(info='e2')).filter(note=self.n1),
+            ['<ExtraInfo: e1>']
+        )
+        self.assertQuerysetEqual(
+            (ExtraInfo.objects.filter(info='e2')|ExtraInfo.objects.filter(note=self.n1)).filter(note=self.n1),
+            ['<ExtraInfo: e1>']
+        )
+
+
+class Queries6Tests(TestCase):
+    def setUp(self):
+        generic = NamedCategory.objects.create(name="Generic")
+        t1 = Tag.objects.create(name='t1', category=generic)
+        t2 = Tag.objects.create(name='t2', parent=t1, category=generic)
+        t3 = Tag.objects.create(name='t3', parent=t1)
+        t4 = Tag.objects.create(name='t4', parent=t3)
+        t5 = Tag.objects.create(name='t5', parent=t3)
+        n1 = Note.objects.create(note='n1', misc='foo', id=1)
+        ann1 = Annotation.objects.create(name='a1', tag=t1)
+        ann1.notes.add(n1)
+        ann2 = Annotation.objects.create(name='a2', tag=t4)
+
+    # FIXME!! This next test causes really weird PostgreSQL behaviour, but it's
+    # only apparent much later when the full test suite runs. I don't understand
+    # what's going on here yet.
+    ##def test_slicing_and_cache_interaction(self):
+    ##    # We can do slicing beyond what is currently in the result cache,
+    ##    # too.
+    ##
+    ##    # We need to mess with the implementation internals a bit here to decrease the
+    ##    # cache fill size so that we don't read all the results at once.
+    ##    from django.db.models import query
+    ##    query.ITER_CHUNK_SIZE = 2
+    ##    qs = Tag.objects.all()
+    ##
+    ##    # Fill the cache with the first chunk.
+    ##    self.assertTrue(bool(qs))
+    ##    self.assertEqual(len(qs._result_cache), 2)
+    ##
+    ##    # Query beyond the end of the cache and check that it is filled out as required.
+    ##    self.assertEqual(repr(qs[4]), '<Tag: t5>')
+    ##    self.assertEqual(len(qs._result_cache), 5)
+    ##
+    ##    # But querying beyond the end of the result set will fail.
+    ##    self.assertRaises(IndexError, lambda: qs[100])
+
+    def test_parallel_iterators(self):
+        # Test that parallel iterators work.
+        qs = Tag.objects.all()
+        i1, i2 = iter(qs), iter(qs)
+        self.assertEqual(repr(i1.next()), '<Tag: t1>')
+        self.assertEqual(repr(i1.next()), '<Tag: t2>')
+        self.assertEqual(repr(i2.next()), '<Tag: t1>')
+        self.assertEqual(repr(i2.next()), '<Tag: t2>')
+        self.assertEqual(repr(i2.next()), '<Tag: t3>')
+        self.assertEqual(repr(i1.next()), '<Tag: t3>')
+
+        qs = X.objects.all()
+        self.assertEqual(bool(qs), False)
+        self.assertEqual(bool(qs), False)
+
+    def test_nested_queries_sql(self):
+        # Nested queries should not evaluate the inner query as part of constructing the
+        # SQL (so we should see a nested query here, indicated by two "SELECT" calls).
+        qs = Annotation.objects.filter(notes__in=Note.objects.filter(note="xyzzy"))
+        self.assertEqual(
+            qs.query.get_compiler(qs.db).as_sql()[0].count('SELECT'),
+            2
+        )
+
+    def test_tickets_8921_9188(self):
+        # Incorrect SQL was being generated for certain types of exclude()
+        # queries that crossed multi-valued relations (#8921, #9188 and some
+        # pre-emptively discovered cases).
+
+        self.assertQuerysetEqual(
+            PointerA.objects.filter(connection__pointerb__id=1),
+            []
+        )
+        self.assertQuerysetEqual(
+            PointerA.objects.exclude(connection__pointerb__id=1),
+            []
+        )
+
+        self.assertQuerysetEqual(
+            Tag.objects.exclude(children=None),
+            ['<Tag: t1>', '<Tag: t3>']
+        )
+
+        # This example is tricky because the parent could be NULL, so only checking
+        # parents with annotations omits some results (tag t1, in this case).
+        self.assertQuerysetEqual(
+            Tag.objects.exclude(parent__annotation__name="a1"),
+            ['<Tag: t1>', '<Tag: t4>', '<Tag: t5>']
+        )
+
+        # The annotation->tag link is single values and tag->children links is
+        # multi-valued. So we have to split the exclude filter in the middle
+        # and then optimise the inner query without losing results.
+        self.assertQuerysetEqual(
+            Annotation.objects.exclude(tag__children__name="t2"),
+            ['<Annotation: a2>']
+        )
+
+        # Nested queries are possible (although should be used with care, since
+        # they have performance problems on backends like MySQL.
+
+        self.assertQuerysetEqual(
+            Annotation.objects.filter(notes__in=Note.objects.filter(note="n1")),
+            ['<Annotation: a1>']
+        )
+
+    def test_ticket3739(self):
+        # The all() method on querysets returns a copy of the queryset.
+        q1 = Tag.objects.order_by('name')
+        self.assertTrue(q1 is not q1.all())
+
+
+class GeneratorExpressionTests(TestCase):
+    def test_ticket10432(self):
+        # Using an empty generator expression as the rvalue for an "__in"
+        # lookup is legal.
+        self.assertQuerysetEqual(
+            Note.objects.filter(pk__in=(x for x in ())),
+            []
+        )
+
+
+class ComparisonTests(TestCase):
+    def setUp(self):
+        self.n1 = Note.objects.create(note='n1', misc='foo', id=1)
+        e1 = ExtraInfo.objects.create(info='e1', note=self.n1)
+        self.a2 = Author.objects.create(name='a2', num=2002, extra=e1)
+
+    def test_ticket8597(self):
+        # Regression tests for case-insensitive comparisons
+        _ = Item.objects.create(name="a_b", created=datetime.datetime.now(), creator=self.a2, note=self.n1)
+        _ = Item.objects.create(name="x%y", created=datetime.datetime.now(), creator=self.a2, note=self.n1)
+        self.assertQuerysetEqual(
+            Item.objects.filter(name__iexact="A_b"),
+            ['<Item: a_b>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(name__iexact="x%Y"),
+            ['<Item: x%y>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(name__istartswith="A_b"),
+            ['<Item: a_b>']
+        )
+        self.assertQuerysetEqual(
+            Item.objects.filter(name__iendswith="A_b"),
+            ['<Item: a_b>']
+        )
+
+
+class ExistsSql(TestCase):
+    def setUp(self):
+        settings.DEBUG = True
+
+    def test_exists(self):
+        self.assertFalse(Tag.objects.exists())
+        # Ok - so the exist query worked - but did it include too many columns?
+        self.assertTrue("id" not in connection.queries[-1]['sql'] and "name" not in connection.queries[-1]['sql'])
+
+    def tearDown(self):
+        settings.DEBUG = False
+
+
+class QuerysetOrderedTests(unittest.TestCase):
+    """
+    Tests for the Queryset.ordered attribute.
+    """
+
+    def test_no_default_or_explicit_ordering(self):
+        self.assertEqual(Annotation.objects.all().ordered, False)
+
+    def test_cleared_default_ordering(self):
+        self.assertEqual(Tag.objects.all().ordered, True)
+        self.assertEqual(Tag.objects.all().order_by().ordered, False)
+
+    def test_explicit_ordering(self):
+        self.assertEqual(Annotation.objects.all().order_by('id').ordered, True)
+
+    def test_order_by_extra(self):
+        self.assertEqual(Annotation.objects.all().extra(order_by=['id']).ordered, True)
+
+    def test_annotated_ordering(self):
+        qs = Annotation.objects.annotate(num_notes=Count('notes'))
+        self.assertEqual(qs.ordered, False)
+        self.assertEqual(qs.order_by('num_notes').ordered, True)
+
+
+class SubqueryTests(TestCase):
+    def setUp(self):
+        DumbCategory.objects.create(id=1)
+        DumbCategory.objects.create(id=2)
+        DumbCategory.objects.create(id=3)
+
+    def test_ordered_subselect(self):
+        "Subselects honor any manual ordering"
+        try:
+            query = DumbCategory.objects.filter(id__in=DumbCategory.objects.order_by('-id')[0:2])
+            self.assertEquals(set(query.values_list('id', flat=True)), set([2,3]))
+
+            query = DumbCategory.objects.filter(id__in=DumbCategory.objects.order_by('-id')[:2])
+            self.assertEquals(set(query.values_list('id', flat=True)), set([2,3]))
+
+            query = DumbCategory.objects.filter(id__in=DumbCategory.objects.order_by('-id')[2:])
+            self.assertEquals(set(query.values_list('id', flat=True)), set([1]))
+        except DatabaseError:
+            # Oracle and MySQL both have problems with sliced subselects.
+            # This prevents us from even evaluating this test case at all.
+            # Refs #10099
+            self.assertFalse(connections[DEFAULT_DB_ALIAS].features.allow_sliced_subqueries)
+
+    def test_sliced_delete(self):
+        "Delete queries can safely contain sliced subqueries"
+        try:
+            DumbCategory.objects.filter(id__in=DumbCategory.objects.order_by('-id')[0:1]).delete()
+            self.assertEquals(set(DumbCategory.objects.values_list('id', flat=True)), set([1,2]))
+        except DatabaseError:
+            # Oracle and MySQL both have problems with sliced subselects.
+            # This prevents us from even evaluating this test case at all.
+            # Refs #10099
+            self.assertFalse(connections[DEFAULT_DB_ALIAS].features.allow_sliced_subqueries)
+
+
+class CloneTests(TestCase):
+    def test_evaluated_queryset_as_argument(self):
+        "#13227 -- If a queryset is already evaluated, it can still be used as a query arg"
+        n = Note(note='Test1', misc='misc')
+        n.save()
+        e = ExtraInfo(info='good', note=n)
+        e.save()
+
+        n_list = Note.objects.all()
+        # Evaluate the Note queryset, populating the query cache
+        list(n_list)
+        # Use the note queryset in a query, and evalute
+        # that query in a way that involves cloning.
+        try:
+            self.assertEquals(ExtraInfo.objects.filter(note__in=n_list)[0].info, 'good')
+        except:
+            self.fail('Query should be clonable')
+
+
+class EmptyQuerySetTests(TestCase):
+    def test_emptyqueryset_values(self):
+        # #14366 -- Calling .values() on an EmptyQuerySet and then cloning that
+        # should not cause an error"
+        self.assertQuerysetEqual(
+            Number.objects.none().values('num').order_by('num'), []
+        )
+
+    def test_values_subquery(self):
+        self.assertQuerysetEqual(
+            Number.objects.filter(pk__in=Number.objects.none().values("pk")),
+            []
+        )
+        self.assertQuerysetEqual(
+            Number.objects.filter(pk__in=Number.objects.none().values_list("pk")),
+            []
+        )
+
+
+class ValuesQuerysetTests(BaseQuerysetTest):
+    def test_flat_values_lits(self):
+        Number.objects.create(num=72)
+        qs = Number.objects.values_list("num")
+        qs = qs.values_list("num", flat=True)
+        self.assertValueQuerysetEqual(
+            qs, [72]
+        )
+
+
+class WeirdQuerysetSlicingTests(BaseQuerysetTest):
+    def setUp(self):
+        Number.objects.create(num=1)
+        Number.objects.create(num=2)
+
+        Article.objects.create(name='one', created=datetime.datetime.now())
+        Article.objects.create(name='two', created=datetime.datetime.now())
+        Article.objects.create(name='three', created=datetime.datetime.now())
+        Article.objects.create(name='four', created=datetime.datetime.now())
+
+    def test_tickets_7698_10202(self):
+        # People like to slice with '0' as the high-water mark.
+        self.assertQuerysetEqual(Article.objects.all()[0:0], [])
+        self.assertQuerysetEqual(Article.objects.all()[0:0][:10], [])
+        self.assertEqual(Article.objects.all()[:0].count(), 0)
+        self.assertRaisesMessage(
+            AssertionError,
+            'Cannot change a query once a slice has been taken.',
+            Article.objects.all()[:0].latest, 'created'
+        )
+
+
+class EscapingTests(TestCase):
+    def test_ticket_7302(self):
+        # Reserved names are appropriately escaped
+        _ = ReservedName.objects.create(name='a', order=42)
+        ReservedName.objects.create(name='b', order=37)
+        self.assertQuerysetEqual(
+            ReservedName.objects.all().order_by('order'),
+            ['<ReservedName: b>', '<ReservedName: a>']
+        )
+        self.assertQuerysetEqual(
+            ReservedName.objects.extra(select={'stuff':'name'}, order_by=('order','stuff')),
+            ['<ReservedName: b>', '<ReservedName: a>']
+        )
+
+
+# In Python 2.6 beta releases, exceptions raised in __len__ are swallowed
+# (Python issue 1242657), so these cases return an empty list, rather than
+# raising an exception. Not a lot we can do about that, unfortunately, due to
+# the way Python handles list() calls internally. Thus, we skip the tests for
+# Python 2.6.
+if sys.version_info[:2] != (2, 6):
+    class OrderingLoopTests(BaseQuerysetTest):
+        def setUp(self):
+            generic = NamedCategory.objects.create(name="Generic")
+            t1 = Tag.objects.create(name='t1', category=generic)
+            t2 = Tag.objects.create(name='t2', parent=t1, category=generic)
+            t3 = Tag.objects.create(name='t3', parent=t1)
+            t4 = Tag.objects.create(name='t4', parent=t3)
+            t5 = Tag.objects.create(name='t5', parent=t3)
+
+        def test_infinite_loop(self):
+            # If you're not careful, it's possible to introduce infinite loops via
+            # default ordering on foreign keys in a cycle. We detect that.
+            self.assertRaisesMessage(
+                FieldError,
+                'Infinite loop caused by ordering.',
+                lambda: list(LoopX.objects.all()) # Force queryset evaluation with list()
+            )
+            self.assertRaisesMessage(
+                FieldError,
+                'Infinite loop caused by ordering.',
+                lambda: list(LoopZ.objects.all()) # Force queryset evaluation with list()
+            )
+
+            # Note that this doesn't cause an infinite loop, since the default
+            # ordering on the Tag model is empty (and thus defaults to using "id"
+            # for the related field).
+            self.assertEqual(len(Tag.objects.order_by('parent')), 5)
+
+            # ... but you can still order in a non-recursive fashion amongst linked
+            # fields (the previous test failed because the default ordering was
+            # recursive).
+            self.assertQuerysetEqual(
+                LoopX.objects.all().order_by('y__x__y__x__id'),
+                []
+            )
+
+
+# When grouping without specifying ordering, we add an explicit "ORDER BY NULL"
+# portion in MySQL to prevent unnecessary sorting.
+if settings.DATABASES[DEFAULT_DB_ALIAS]['ENGINE'] == "django.db.backends.mysql":
+    class GroupingTests(TestCase):
+        def test_null_ordering_added(self):
+            query = Tag.objects.values_list('parent_id', flat=True).order_by().query
+            query.group_by = ['parent_id']
+            sql = query.get_compiler(DEFAULT_DB_ALIAS).as_sql()[0]
+            fragment = "ORDER BY "
+            pos = sql.find(fragment)
+            self.assertEqual(sql.find(fragment, pos + 1), -1)
+            self.assertEqual(sql.find("NULL", pos + len(fragment)), pos + len(fragment))
+
+
+# Sqlite 3 does not support passing in more than 1000 parameters except by
+# changing a parameter at compilation time.
+if settings.DATABASES[DEFAULT_DB_ALIAS]['ENGINE'] != "django.db.backends.sqlite3":
+    class InLookupTests(TestCase):
+        def test_ticket14244(self):
+            # Test that the "in" lookup works with lists of 1000 items or more.
+            Number.objects.all().delete()
+            numbers = range(2500)
+            for num in numbers:
+                _ = Number.objects.create(num=num)
+            self.assertEqual(
+                Number.objects.filter(num__in=numbers[:1000]).count(),
+                1000
+            )
+            self.assertEqual(
+                Number.objects.filter(num__in=numbers[:1001]).count(),
+                1001
+            )
+            self.assertEqual(
+                Number.objects.filter(num__in=numbers[:2000]).count(),
+                2000
+            )
+            self.assertEqual(
+                Number.objects.filter(num__in=numbers).count(),
+                2500
+            )