diff options
Diffstat (limited to 'lib/sqlalchemy/ext/declarative.py')
| -rw-r--r-- | lib/sqlalchemy/ext/declarative.py | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/sqlalchemy/ext/declarative.py b/lib/sqlalchemy/ext/declarative.py index 2a6facb55..8a58ca25d 100644 --- a/lib/sqlalchemy/ext/declarative.py +++ b/lib/sqlalchemy/ext/declarative.py @@ -328,7 +328,10 @@ class _GetColumns(object): if not mapper: return getattr(self.cls, key) else: - return mapper.get_property(key).columns[0] + prop = mapper.get_property(key) + if not isinstance(prop, ColumnProperty): + raise exceptions.InvalidRequestError("Property %r is not an instance of ColumnProperty (i.e. does not correspnd directly to a Column)." % key) + return prop.columns[0] def _deferred_relation(cls, prop): |