- The behavior of the :func:`.union` construct and related constructs

such as :meth:`.Query.union` now handle the case where the embedded
SELECT statements need to be parenthesized due to the fact that they
include LIMIT, OFFSET and/or ORDER BY.   These queries **do not work
on SQLite**, and will fail on that backend as they did before, but
should now work on all other backends.
fixes #2528

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/sqlalchemy/testing/requirements.py b/lib/sqlalchemy/testing/requirements.py
index e8b3a995f..8b02f3e40 100644
--- a/lib/sqlalchemy/testing/requirements.py
+++ b/lib/sqlalchemy/testing/requirements.py
@@ -111,6 +111,17 @@ class SuiteRequirements(Requirements):
         return exclusions.open()
 
     @property
+    def parens_in_union_contained_select(self):
+        """Target database must support parenthesized SELECT in UNION.
+
+        E.g. (SELECT ...) UNION (SELECT ..)
+
+        This is known to fail on SQLite.
+
+        """
+        return exclusions.open()
+
+    @property
     def boolean_col_expressions(self):
         """Target database must support boolean expressions as columns"""