diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py index df4de2a750..f4bf8b2b07 100644 --- a/django/db/models/sql/query.py +++ b/django/db/models/sql/query.py @@ -124,8 +124,13 @@ class BaseQuery(object): obj_dict['related_select_cols'] = [] del obj_dict['connection'] - # Fields can't be pickled, so we pickle the list of field names instead. - obj_dict['select_fields'] = [f.name for f in obj_dict['select_fields']] + # Fields can't be pickled, so if a field list has been + # specified, we pickle the list of field names instead. + # None is also a possible value; that can pass as-is + obj_dict['select_fields'] = [ + f is not None and f.name or None + for f in obj_dict['select_fields'] + ] return obj_dict def __setstate__(self, obj_dict): @@ -133,7 +138,10 @@ class BaseQuery(object): Unpickling support. """ # Rebuild list of field instances - obj_dict['select_fields'] = [obj_dict['model']._meta.get_field(name) for name in obj_dict['select_fields']] + obj_dict['select_fields'] = [ + name is not None and obj_dict['model']._meta.get_field(name) or None + for name in obj_dict['select_fields'] + ] self.__dict__.update(obj_dict) # XXX: Need a better solution for this when multi-db stuff is