Fixed #31044 -- Errored nicely when using Prefetch with a raw() queryset.

1 files changed, 7 insertions, 1 deletions

diff --git a/tests/prefetch_related/tests.py b/tests/prefetch_related/tests.py
index 5b944a456b..35c2a1c6b8 100644
--- a/tests/prefetch_related/tests.py
+++ b/tests/prefetch_related/tests.py
@@ -815,12 +815,18 @@ class CustomPrefetchTests(TestCase):
             self.traverse_qs(list(houses), [['occupants', 'houses', 'main_room']])
 
     def test_values_queryset(self):
-        with self.assertRaisesMessage(ValueError, 'Prefetch querysets cannot use values().'):
+        msg = 'Prefetch querysets cannot use raw() and values().'
+        with self.assertRaisesMessage(ValueError, msg):
             Prefetch('houses', House.objects.values('pk'))
         # That error doesn't affect managers with custom ModelIterable subclasses
         self.assertIs(Teacher.objects_custom.all()._iterable_class, ModelIterableSubclass)
         Prefetch('teachers', Teacher.objects_custom.all())
 
+    def test_raw_queryset(self):
+        msg = 'Prefetch querysets cannot use raw() and values().'
+        with self.assertRaisesMessage(ValueError, msg):
+            Prefetch('houses', House.objects.raw('select pk from house'))
+
     def test_to_attr_doesnt_cache_through_attr_as_list(self):
         house = House.objects.prefetch_related(
             Prefetch('rooms', queryset=Room.objects.all(), to_attr='to_rooms'),