1 files changed, 15 insertions, 0 deletions
diff --git a/django/db/models/sql/datastructures.py b/django/db/models/sql/datastructures.py
index b32148eba5..f45ecaf76d 100644
--- a/django/db/models/sql/datastructures.py
+++ b/django/db/models/sql/datastructures.py
@@ -4,6 +4,21 @@ the SQL domain.
 """
 
 
+class Col(object):
+    def __init__(self, alias, col):
+        self.alias = alias
+        self.col = col
+
+    def as_sql(self, qn, connection):
+        return '%s.%s' % (qn(self.alias), self.col), []
+
+    def prepare(self):
+        return self
+
+    def relabeled_clone(self, relabels):
+        return self.__class__(relabels.get(self.alias, self.alias), self.col)
+
+
 class EmptyResultSet(Exception):
     pass