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django/tests/regressiontests/queries/tests.py
Ramiro Morales 08d14925c9 Fixed #12192 -- Don't execute any DB query when the QS slicing being performed
will result in use of LIMIT 0. Thanks Suor for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14204 bcc190cf-cafb-0310-a4f2-bffc1f526a37
2010-10-13 23:36:16 +00:00

104 lines
4.1 KiB
Python

from django.db import DatabaseError, connections, DEFAULT_DB_ALIAS
from django.db.models import Count
from django.test import TestCase
from django.utils import unittest
from models import Tag, Annotation, DumbCategory, Note, ExtraInfo, Number
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.assertEqual(list(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")), []
)
class WeirdQuerySetSlicing(TestCase):
def setUp(self):
Number.objects.create(num=1)
Number.objects.create(num=2)
def test_empty_resultset_sql(self):
# ticket #12192
self.assertNumQueries(0, lambda: list(Number.objects.all()[1:1]))