- Fixed bug whereby with_only_columns() method of

    Select would fail if a selectable were passed.
    [ticket:2270].  Also in 0.6.9.

1 files changed, 7 insertions, 5 deletions

diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index 84fcbd569..9a7f5e376 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -4610,11 +4610,13 @@ class Select(_SelectBase):
 
         """
         self._reset_exported()
-        self._raw_columns = [
-                isinstance(c, _ScalarSelect) and 
-                c.self_group(against=operators.comma_op) or c
-                for c in [_literal_as_column(c) for c in columns]
-            ]
+        rc = []
+        for c in columns:
+            c = _literal_as_column(c)
+            if isinstance(c, _ScalarSelect):
+                c = c.self_group(against=operators.comma_op)
+            rc.append(c)
+        self._raw_columns = rc
 
     @_generative
     def where(self, whereclause):