'Get all objects having a given db field property.
Args:
property_name (str): The name of the field to match for.
candidates (list, optional): Only search among th egiven candidates.
Returns:
matches (list): The found matches.'

@returns_typeclass_list
def get_objs_with_db_property(self, property_name, candidates=None):

    property_name = ('db_%s' % property_name.lstrip('db_'))
    cand_restriction = (((candidates is not None) and Q(pk__in=[_GA(obj, 'id') for obj in make_iter(candidates) if obj])) or Q())
    querykwargs = {property_name: None}
    try:
        return list(self.filter(cand_restriction).exclude(Q(**querykwargs)))
    except exceptions.FieldError:
        return []
