CompoundSelect (i.e. UNION etc.) needed self_group() to provide parenthesis

2 files changed, 13 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py
index 9a93474dc..4304d1ecc 100644
--- a/lib/sqlalchemy/sql.py
+++ b/lib/sqlalchemy/sql.py
@@ -2698,6 +2698,9 @@ class CompoundSelect(_SelectBaseMixin, FromClause):
 
     name = property(lambda s:s.keyword + " statement")
 
+    def self_group(self, against=None):
+        return _Grouping(self)
+
     def _locate_oid_column(self):
         return self.selects[0].oid_column
 
diff --git a/test/sql/select.py b/test/sql/select.py
index 281a0f6a3..2f627ee8f 100644
--- a/test/sql/select.py
+++ b/test/sql/select.py
@@ -821,6 +821,16 @@ myothertable.othername != :myothertable_othername OR EXISTS (select yay from foo
 
         self.runtest(select([table1], ~table1.c.myid.in_(select([table2.c.otherid]))),
         "SELECT mytable.myid, mytable.name, mytable.description FROM mytable WHERE mytable.myid NOT IN (SELECT myothertable.otherid FROM myothertable)")
+
+        self.runtest(select([table1], table1.c.myid.in_(
+            union(
+                  select([table1], table1.c.myid == 5),
+                  select([table1], table1.c.myid == 12),
+            )
+        )), "SELECT mytable.myid, mytable.name, mytable.description FROM mytable \
+WHERE mytable.myid IN (\
+SELECT mytable.myid, mytable.name, mytable.description FROM mytable WHERE mytable.myid = :mytable_myid \
+UNION SELECT mytable.myid, mytable.name, mytable.description FROM mytable WHERE mytable.myid = :mytable_myid_1)")
         
         # test that putting a select in an IN clause does not blow away its ORDER BY clause
         self.runtest(