这样的 sql 用查询构造器该怎么写和用 ORM 该怎么写

  $sql = "select a.name,b.displayname  from  roles a  inner join 
                (
                        select role_id,group_concat( DISTINCT displayname SEPARATOR ',') as displayname  
                        from role_has_permissions b  
                        left join perssion c on b.perssion_id=c.id
                        GROUP BY role_id order by role_id asc

                ) b on a.id=b.role_id";