Refs #30188 -- Prevented double annotation of subquery when aggregated over.

Thanks Can Sarıgöl for the suggested trimming approach.

1 files changed, 13 insertions, 9 deletions

diff --git a/tests/expressions/tests.py b/tests/expressions/tests.py
index bb448745c8..a51080ef13 100644
--- a/tests/expressions/tests.py
+++ b/tests/expressions/tests.py
@@ -553,16 +553,20 @@ class BasicExpressionsTests(TestCase):
 
     @skipUnlessDBFeature('supports_subqueries_in_group_by')
     def test_aggregate_subquery_annotation(self):
-        aggregate = Company.objects.annotate(
-            ceo_salary=Subquery(
-                Employee.objects.filter(
-                    id=OuterRef('ceo_id'),
-                ).values('salary')
-            ),
-        ).aggregate(
-            ceo_salary_gt_20=Count('pk', filter=Q(ceo_salary__gt=20)),
-        )
+        with self.assertNumQueries(1) as ctx:
+            aggregate = Company.objects.annotate(
+                ceo_salary=Subquery(
+                    Employee.objects.filter(
+                        id=OuterRef('ceo_id'),
+                    ).values('salary')
+                ),
+            ).aggregate(
+                ceo_salary_gt_20=Count('pk', filter=Q(ceo_salary__gt=20)),
+            )
         self.assertEqual(aggregate, {'ceo_salary_gt_20': 1})
+        # Aggregation over a subquery annotation doesn't annotate the subquery
+        # twice in the inner query.
+        self.assertLessEqual(ctx.captured_queries[0]['sql'].count('SELECT'), 4,)
 
     def test_explicit_output_field(self):
         class FuncA(Func):