- [feature] Conflicts between columns on

    single-inheritance declarative subclasses,
    with or without using a mixin, can be resolved
    using a new @declared_attr usage described
    in the documentation.  [ticket:2472]

1 files changed, 6 insertions, 1 deletions

diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py
index 12c38b595..272d4edd5 100644
--- a/lib/sqlalchemy/orm/interfaces.py
+++ b/lib/sqlalchemy/orm/interfaces.py
@@ -65,7 +65,12 @@ class _InspectionAttr(object):
     is_attribute = False
     is_clause_element = False
 
-class MapperProperty(_InspectionAttr):
+class _MappedAttribute(object):
+    """Mixin for attributes which should be replaced by mapper-assigned
+    attributes.
+
+    """
+class MapperProperty(_MappedAttribute, _InspectionAttr):
     """Manage the relationship of a ``Mapper`` to a single class
     attribute, as well as that attribute as it appears on individual
     instances of the class, including attribute instrumentation,