From 0527e22a242e2cd1cdc7bd8260bc81d0a3b48b01 Mon Sep 17 00:00:00 2001
From: Alexander Schepanovski <suor.web@gmail.com>
Date: Sat, 26 Sep 2020 19:05:11 +0700
Subject: [PATCH] Fix annotations introspection in Django 3.0

---
 cacheops/tree.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/cacheops/tree.py b/cacheops/tree.py
index 40f8e2ab..f7737e23 100644
--- a/cacheops/tree.py
+++ b/cacheops/tree.py
@@ -130,7 +130,8 @@ def table_for(alias):
     if qs.query.annotations:
         subqueries = (
             # Django 3.0+ sets Subquery.query
-            query_dnf(getattr(q, 'query', q.queryset.query)) for q in qs.query.annotations.values()
+            query_dnf(getattr(q, 'query', None) or getattr(q, 'queryset').query)
+            for q in qs.query.annotations.values()
             if type(q) is Subquery
         )
         dnfs_.update(join_with(lcat, subqueries))