- fixed bug where "from" clause gathering from an

    over() clause would be an itertools.chain() and
    not a list, causing "can only concatenate list"
    TypeError when combined with other clauses.

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index f5ec41a60..c9647e1bd 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -3704,11 +3704,11 @@ class _Over(ColumnElement):
 
     @property
     def _from_objects(self):
-        return itertools.chain(
+        return list(itertools.chain(
             *[c._from_objects for c in 
                 (self.func, self.partition_by, self.order_by) 
             if c is not None]
-        )
+        ))
 
 class _Label(ColumnElement):
     """Represents a column label (AS).