diff options
Diffstat (limited to 'lib/sqlalchemy/sql/coercions.py')
| -rw-r--r-- | lib/sqlalchemy/sql/coercions.py | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/lib/sqlalchemy/sql/coercions.py b/lib/sqlalchemy/sql/coercions.py index a7a856bba..95aee0468 100644 --- a/lib/sqlalchemy/sql/coercions.py +++ b/lib/sqlalchemy/sql/coercions.py @@ -57,7 +57,7 @@ def expect(role, element, **kw): else: resolved = element - if issubclass(resolved.__class__, impl._role_class): + if impl._role_class in resolved.__class__.__mro__: if impl._post_coercion: resolved = impl._post_coercion(resolved, **kw) return resolved @@ -102,13 +102,16 @@ class RoleImpl(object): def _resolve_for_clause_element(self, element, argname=None, **kw): original_element = element - is_clause_element = False + is_clause_element = hasattr(element, "__clause_element__") - while hasattr(element, "__clause_element__") and not isinstance( - element, (elements.ClauseElement, schema.SchemaItem) - ): - element = element.__clause_element__() - is_clause_element = True + if is_clause_element: + while not isinstance( + element, (elements.ClauseElement, schema.SchemaItem) + ): + try: + element = element.__clause_element__() + except AttributeError: + break if not is_clause_element: if self._use_inspection: |