Fixed bug in type_coerce() whereby typing information

could be lost if the statement were used as a subquery
inside of another statement, as well as other similar
situations.  Among other things, would cause
typing information to be lost when the Oracle/mssql dialects
would apply limit/offset wrappings. [ticket:2603]

1 files changed, 9 insertions, 0 deletions

diff --git a/test/sql/test_selectable.py b/test/sql/test_selectable.py
index 53c9018cd..65dc65470 100644
--- a/test/sql/test_selectable.py
+++ b/test/sql/test_selectable.py
@@ -228,6 +228,15 @@ class SelectableTest(fixtures.TestBase, AssertsExecutionResults, AssertsCompiled
             "table1.col3, table1.colx FROM table1) AS anon_1"
         )
 
+    def test_type_coerce_preserve_subq(self):
+        class MyType(TypeDecorator):
+            impl = Integer
+
+        stmt = select([type_coerce(column('x'), MyType).label('foo')])
+        stmt2 = stmt.select()
+        assert isinstance(stmt._raw_columns[0].type, MyType)
+        assert isinstance(stmt.c.foo.type, MyType)
+        assert isinstance(stmt2.c.foo.type, MyType)
 
     def test_select_on_table(self):
         sel = select([table1, table2], use_labels=True)