把多条记录中的某个字段合并为字符串

select u."USERID",
       u."OFFICEID",
       u."DEPARTMENTID",
       u."NAME",
       u."POSITION",
       u."TEL",
       u."DXTEL",
       u."TEL2",
       u."EMPNO",
       u."USERNO",
       rownum as Sequence
  from (select u.userid,
               u.officeid,
               u.departmentid,
               u.name,
               p.name as position,
               u.tel,
               u.dxtel,
               u.Tel2,
               u.empno,
               u.userno
          from sys_user u
          join (SELECT u.userid, wm_concat(p.name) AS name
                 FROM sys_user_post u
                 join sys_post p
                   on u.postid = p.id
                GROUP BY u.userid) p
            on u.userid = p.userid
          join VW_SYS_OFFICE_ORDER o2
            on u.departmentid = o2.OrderOfficeId
          join vw_sys_office c
            on u.officeid = c.id
           and c.sequence >= 0
         where (u.IsActive is null or u.IsActive = 1 and u.usertype != 2)
         order by o2.OfficeSquence, u.Sequence) u;