diff options
Diffstat (limited to 'lib/sqlalchemy/orm/attributes.py')
| -rw-r--r-- | lib/sqlalchemy/orm/attributes.py | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/lib/sqlalchemy/orm/attributes.py b/lib/sqlalchemy/orm/attributes.py index 9e326db64..0c7bc4cf0 100644 --- a/lib/sqlalchemy/orm/attributes.py +++ b/lib/sqlalchemy/orm/attributes.py @@ -46,6 +46,7 @@ from .base import RELATED_OBJECT_OK # noqa from .base import SQL_OK # noqa from .base import state_str from .. import event +from .. import exc from .. import inspection from .. import util from ..sql import base as sql_base @@ -229,7 +230,20 @@ class QueryableAttribute( "entity_namespace": self._entity_namespace, } - return self.comparator.__clause_element__()._annotate(annotations) + ce = self.comparator.__clause_element__() + try: + anno = ce._annotate + except AttributeError as ae: + util.raise_( + exc.InvalidRequestError( + 'When interpreting attribute "%s" as a SQL expression, ' + "expected __clause_element__() to return " + "a ClauseElement object, got: %r" % (self, ce) + ), + from_=ae, + ) + else: + return anno(annotations) @property def _entity_namespace(self): |