Oracle Decode行变列

select resid, delay, discard
  from (select a.resid,
               sum(decode(a.ditemid, 'aaa', a.value, '')) ||
               sum(decode(a.ditemid, 'B_WebDNSDW', a.value, '')) delay,
               sum(decode(a.ditemid, 'B_WebTCPDelayW', a.value, null)) ||
               sum(decode(a.ditemid, 'bbb', a.value, '')) discard
          from (select resid, ditemid, value
                  from rmcinfo t
                 where ditemid IN ('B_WebDNSDW', 'B_WebTCPDW')
                   and resid = 'APP02op7') a
         group by a.resid)