Fixed #13349 -- Ensure that raw queries evaluate the entire query if the backend doesn't support chunked reads. Thanks to Alex Gaynor for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12978 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/sql/query.py

@@ -71,7 +71,13 @@ class RawQuery(object):
         # Always execute a new query for a new iterator.
         # This could be optimized with a cache at the expense of RAM.
         self._execute_query()
-        return iter(self.cursor)
+        if not connections[self.using].features.can_use_chunked_reads:
+            # If the database can't use chunked reads we need to make sure we
+            # evaluate the entire query up front.
+            result = list(self.cursor)
+        else:
+            result = self.cursor
+        return iter(result)
 
     def __repr__(self):
         return "<RawQuery: %r>" % (self.sql % self.params)