def __get_rv(self, base_sql_ast=None, cursor=None):
    sql_ast = self.get_sql_ast(base_sql_ast=base_sql_ast)
    return self._get_rv_by_sql_ast(sql_ast, cursor=cursor)
def __get_rv(self, base_sql_ast=None, cursor=None):
    sql_ast = self.get_sql_ast(base_sql_ast=base_sql_ast)
    return self._get_rv_by_sql_ast(sql_ast, cursor=cursor)