关于select 高性能修改

  select departid,res,departname,upgradeid,orderid,levelid ,(select count(departid) from org_depart where upgradeid = a.departid) as num from org_depart a  where 1=1  and orgid = 'buju@xf' and upgradeid = 'eb09df352cda4902b24c54dd2b2ce656'  order by orderid,departname limit 0,30