(no commit message)

diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py
index b2bb32656c1616ed6f54f72b1a531de0b2692ace..f2617d2a2b0bb8e2c9196bc98cd45579c75a3014 100644 (file)
--- a/lib/sqlalchemy/sql.py
+++ b/lib/sqlalchemy/sql.py
@@ -408,6 +408,8 @@ class Join(Selectable):
         self.onclause = onclause
         self.isouter = isouter
 
+    primary_keys = property (lambda self: [c for c in self.left.columns if c.primary_key] + [c for c in self.right.columns if c.primary_key])
+
     def hash_key(self):
         return "Join(%s, %s, %s, %s)" % (repr(self.left.hash_key()), repr(self.right.hash_key()), repr(self.onclause.hash_key()), repr(self.isouter))