Fixed #22434 -- Retain ordering on related sliced subqueries. (a13df671) · Commits · Dom Sekotill / django

django/db/models/sql/where.py

+3 −1

Original line number	Diff line number	Diff line
		@@ -418,6 +418,8 @@ class SubqueryConstraint(object):
		else:
		query = query._clone()
		query = query.query
		if query.can_filter():
		# If there is no slicing in use, then we can safely drop all ordering
		query.clear_ordering(True)

		query_compiler = query.get_compiler(connection=connection)

tests/queries/tests.py

+40 −41

Original line number	Diff line number	Diff line
		@@ -8,7 +8,7 @@ import unittest
		import warnings

		from django.core.exceptions import FieldError
		from django.db import DatabaseError, connection, connections, DEFAULT_DB_ALIAS
		from django.db import connection, DEFAULT_DB_ALIAS
		from django.db.models import Count, F, Q
		from django.db.models.sql.where import WhereNode, EverythingNode, NothingNode
		from django.db.models.sql.datastructures import EmptyResultSet
		@@ -1934,6 +1934,7 @@ class QuerysetOrderedTests(unittest.TestCase):
		self.assertEqual(qs.order_by('num_notes').ordered, True)


		@skipUnlessDBFeature('allow_sliced_subqueries')
		class SubqueryTests(TestCase):
		def setUp(self):
		DumbCategory.objects.create(id=1)
		@@ -1943,7 +1944,6 @@ class SubqueryTests(TestCase):

		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.assertEqual(set(query.values_list('id', flat=True)), set([3, 4]))

		@@ -1955,17 +1955,11 @@ class SubqueryTests(TestCase):

		query = DumbCategory.objects.filter(id__in=DumbCategory.objects.order_by('-id')[2:])
		self.assertEqual(set(query.values_list('id', flat=True)), set([1, 2]))
		except DatabaseError as e:
		# 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, str(e))

		def test_slice_subquery_and_query(self):
		"""
		Slice a query that has a sliced subquery
		"""
		try:
		query = DumbCategory.objects.filter(id__in=DumbCategory.objects.order_by('-id')[0:2])[0:2]
		self.assertEqual(set([x.id for x in query]), set([3, 4]))

		@@ -1974,15 +1968,25 @@ class SubqueryTests(TestCase):

		query = DumbCategory.objects.filter(id__in=DumbCategory.objects.order_by('-id')[2:])[1:]
		self.assertEqual(set([x.id for x in query]), set([2]))
		except DatabaseError as e:
		# 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, str(e))

		def test_related_sliced_subquery(self):
		"""
		Related objects constraints can safely contain sliced subqueries.
		refs #22434
		"""
		generic = NamedCategory.objects.create(name="Generic")
		t1 = Tag.objects.create(name='t1', category=generic)
		t2 = Tag.objects.create(name='t2', category=generic)
		ManagedModel.objects.create(data='mm1', tag=t1, public=True)
		mm2 = ManagedModel.objects.create(data='mm2', tag=t2, public=True)

		query = ManagedModel.normal_manager.filter(
		tag__in=Tag.objects.order_by('-id')[:1]
		)
		self.assertEqual(set([x.id for x in query]), set([mm2.id]))

		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.assertEqual(set(DumbCategory.objects.values_list('id', flat=True)), set([1, 2, 3]))

		@@ -1991,11 +1995,6 @@ class SubqueryTests(TestCase):

		DumbCategory.objects.filter(id__in=DumbCategory.objects.order_by('-id')[1:]).delete()
		self.assertEqual(set(DumbCategory.objects.values_list('id', flat=True)), set([3]))
		except DatabaseError as e:
		# 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, str(e))


		class CloneTests(TestCase):