Fixed #30099 -- Fixed invalid SQL when filtering a Subquery by an aggregate.

AUTHORS

@@ -618,6 +618,7 @@ answer newbie questions, and generally made Django that much better:
     Mykola Zamkovoi <nickzam@gmail.com>
     Nagy Károly <charlie@rendszergazda.com>
     Nasimul Haque <nasim.haque@gmail.com>
+    Nasir Hussain <nasirhjafri@gmail.com>
     Natalia Bidart <nataliabidart@gmail.com>
     Nate Bragg <jonathan.bragg@alum.rpi.edu>
     Neal Norwitz <nnorwitz@google.com>

django/db/models/expressions.py

@@ -994,6 +994,7 @@ class Subquery(Expression):
     query which will be resolved when it is applied to that query.
     """
     template = '(%(subquery)s)'
+    contains_aggregate = False
 
     def __init__(self, queryset, output_field=None, **extra):
         self.queryset = queryset

tests/expressions/tests.py

@@ -534,6 +534,18 @@ class BasicExpressionsTests(TestCase):
         outer = Company.objects.filter(pk__in=Subquery(inner.values('pk')))
         self.assertFalse(outer.exists())
 
+    def test_subquery_filter_by_aggregate(self):
+        Number.objects.create(integer=1000, float=1.2)
+        Employee.objects.create(salary=1000)
+        qs = Number.objects.annotate(
+            min_valuable_count=Subquery(
+                Employee.objects.filter(
+                    salary=OuterRef('integer'),
+                ).annotate(cnt=Count('salary')).filter(cnt__gt=0).values('cnt')[:1]
+            ),
+        )
+        self.assertEqual(qs.get().float, 1.2)
+
     def test_explicit_output_field(self):
         class FuncA(Func):
             output_field = models.CharField()