Fixed #24211 -- Removed ValuesQuerySet() and ValuesListQuerySet().

Thanks Anssi Kääriäinen, Marc Tamlyn, and Tim Graham for the reviews.

1 files changed, 1 insertions, 1 deletions

diff --git a/django/db/models/sql/where.py b/django/db/models/sql/where.py
index fe428b2418..3b894b8aed 100644
--- a/django/db/models/sql/where.py
+++ b/django/db/models/sql/where.py
@@ -204,7 +204,7 @@ class SubqueryConstraint(object):
             if query._db and connection.alias != query._db:
                 raise ValueError("Can't do subqueries with queries on different DBs.")
             # Do not override already existing values.
-            if not hasattr(query, 'field_names'):
+            if query._fields is None:
                 query = query.values(*self.targets)
             else:
                 query = query._clone()