- Fixed bug where :func:`.type_coerce` would not interpret ORM

elements with a ``__clause_element__()`` method properly.
[ticket:2849]

3 files changed, 21 insertions, 2 deletions

diff --git a/doc/build/changelog/changelog_08.rst b/doc/build/changelog/changelog_08.rst
index 727931f9a..ab36c76f8 100644
--- a/doc/build/changelog/changelog_08.rst
+++ b/doc/build/changelog/changelog_08.rst
@@ -12,6 +12,14 @@
 
     .. change::
         :tags: bug, sql
+        :tickets: 2849
+        :versions: 0.9.0
+
+        Fixed bug where :func:`.type_coerce` would not interpret ORM
+        elements with a ``__clause_element__()`` method properly.
+
+    .. change::
+        :tags: bug, sql
         :tickets: 2842
         :versions: 0.9.0
 
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py
index f70496418..251102d59 100644
--- a/lib/sqlalchemy/sql/elements.py
+++ b/lib/sqlalchemy/sql/elements.py
@@ -117,8 +117,8 @@ def type_coerce(expr, type_):
     """
     type_ = type_api.to_instance(type_)
 
-    if hasattr(expr, '__clause_expr__'):
-        return type_coerce(expr.__clause_expr__())
+    if hasattr(expr, '__clause_element__'):
+        return type_coerce(expr.__clause_element__(), type_)
     elif isinstance(expr, BindParameter):
         bp = expr._clone()
         bp.type = type_
diff --git a/test/sql/test_types.py b/test/sql/test_types.py
index a2791ee29..f739707f3 100644
--- a/test/sql/test_types.py
+++ b/test/sql/test_types.py
@@ -466,6 +466,17 @@ class UserDefinedTest(fixtures.TablesTest, AssertsCompiledSQL):
             'd1BIND_OUT'
         )
 
+        class MyFoob(object):
+            def __clause_element__(self):
+                return t.c.data
+
+        eq_(
+            testing.db.execute(
+                select([t.c.data, type_coerce(MyFoob(), MyType)])
+            ).fetchall(),
+            [('d1', 'd1BIND_OUT')]
+        )
+
     @classmethod
     def define_tables(cls, metadata):
         class MyType(types.UserDefinedType):