Refs #16614 -- Made QuerySet.iterator() use server-side cursors on PostgreSQL.

Thanks to Josh Smeaton for the idea of implementing server-side cursors
in PostgreSQL from the iterator method, and Anssi Kääriäinen and Kevin
Turner for their previous work. Also Simon Charette and Tim Graham for
review.

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/test_utils/tests.py b/tests/test_utils/tests.py
index 0013452cac..54b83f524b 100644
--- a/tests/test_utils/tests.py
+++ b/tests/test_utils/tests.py
@@ -1069,6 +1069,18 @@ class DisallowedDatabaseQueriesTests(SimpleTestCase):
             Car.objects.first()
 
 
+class DisallowedDatabaseQueriesChunkedCursorsTests(SimpleTestCase):
+    def test_disallowed_database_queries(self):
+        expected_message = (
+            "Database queries aren't allowed in SimpleTestCase. Either use "
+            "TestCase or TransactionTestCase to ensure proper test isolation or "
+            "set DisallowedDatabaseQueriesChunkedCursorsTests.allow_database_queries "
+            "to True to silence this failure."
+        )
+        with self.assertRaisesMessage(AssertionError, expected_message):
+            next(Car.objects.iterator())
+
+
 class AllowedDatabaseQueriesTests(SimpleTestCase):
     allow_database_queries = True