DB2多表關聯更新

//同表更新同類型記錄總數
 update table1 t1 set t1.totlecount=(select count(t2.id) from table1 t2 where t1.lx=t2.lx)

//更新編號
 update table1 t1 set t1.tnum = (select z2.znum from ztable z1,ztable z2 where  t1.zid=z1.id and z1.zid=z2.bsm)