SELECT *
  FROM (select ysxm00, xkh000, pysm00, wbsm00, ygbh00
          from VW_BQ_YSZYS_YDHL
         where 1 = 1
           and yszid0 = '9'
           and yszt00 != 3
           and czbz00 != 2
           and ((PYSM00 like '%aa%') OR (XKH000 like '%aa%')))
 WHERE ROWNUM <= 30