- Standalone expressions in polymorphic_on

propagate to single-table inheritance
subclasses so that they are used in the
WHERE /JOIN clause to limit rows to that
subclass as is the usual behavior.
- make sure implicit map to polymorphic_on expr
handles creating a label().  Use an explicit name
here as _sa_polymorphic_on makes more sense when
poking around in _props.

1 files changed, 50 insertions, 2 deletions

diff --git a/test/orm/inheritance/test_basic.py b/test/orm/inheritance/test_basic.py
index c9aa5fc9b..dab2d5639 100644
--- a/test/orm/inheritance/test_basic.py
+++ b/test/orm/inheritance/test_basic.py
@@ -186,19 +186,62 @@ class PolymorphicOnNotLocalTest(fixtures.MappedTest):
 
         self._roundtrip()
 
-    def test_polymorphic_on_expr_implicit_map(self):
+    def test_polymorphic_on_expr_implicit_map_no_label_joined(self):
         t2, t1 = self.tables.t2, self.tables.t1
         Parent, Child = self.classes.Parent, self.classes.Child
         expr = case([
             (t1.c.x=="p", "parent"),
             (t1.c.x=="c", "child"),
-        ],else_ = t1.c.x).label("foo")
+        ],else_ = t1.c.x)
+        mapper(Parent, t1, polymorphic_identity="parent",
+            polymorphic_on=expr)
+        mapper(Child, t2, inherits=Parent, polymorphic_identity="child")
+
+        self._roundtrip()
+
+    def test_polymorphic_on_expr_implicit_map_w_label_joined(self):
+        t2, t1 = self.tables.t2, self.tables.t1
+        Parent, Child = self.classes.Parent, self.classes.Child
+        expr = case([
+            (t1.c.x=="p", "parent"),
+            (t1.c.x=="c", "child"),
+        ],else_ = t1.c.x).label(None)
         mapper(Parent, t1, polymorphic_identity="parent",
             polymorphic_on=expr)
         mapper(Child, t2, inherits=Parent, polymorphic_identity="child")
 
         self._roundtrip()
 
+    def test_polymorphic_on_expr_implicit_map_no_label_single(self):
+        """test that single_table_criterion is propagated 
+        with a standalone expr"""
+        t2, t1 = self.tables.t2, self.tables.t1
+        Parent, Child = self.classes.Parent, self.classes.Child
+        expr = case([
+            (t1.c.x=="p", "parent"),
+            (t1.c.x=="c", "child"),
+        ],else_ = t1.c.x)
+        mapper(Parent, t1, polymorphic_identity="parent",
+            polymorphic_on=expr)
+        mapper(Child, inherits=Parent, polymorphic_identity="child")
+
+        self._roundtrip()
+
+    def test_polymorphic_on_expr_implicit_map_w_label_single(self):
+        """test that single_table_criterion is propagated 
+        with a standalone expr"""
+        t2, t1 = self.tables.t2, self.tables.t1
+        Parent, Child = self.classes.Parent, self.classes.Child
+        expr = case([
+            (t1.c.x=="p", "parent"),
+            (t1.c.x=="c", "child"),
+        ],else_ = t1.c.x).label(None)
+        mapper(Parent, t1, polymorphic_identity="parent",
+            polymorphic_on=expr)
+        mapper(Child, inherits=Parent, polymorphic_identity="child")
+
+        self._roundtrip()
+
     def test_polymorphic_on_column_prop(self):
         t2, t1 = self.tables.t2, self.tables.t1
         Parent, Child = self.classes.Parent, self.classes.Child
@@ -269,6 +312,11 @@ class PolymorphicOnNotLocalTest(fixtures.MappedTest):
             [Parent, Child, Parent]
         )
 
+        eq_(
+            [type(t) for t in s.query(Child).all()],
+            [Child]
+        )
+
 
 class FalseDiscriminatorTest(fixtures.MappedTest):
     @classmethod