select * from (select n.* from (SELECT m.sid, @rowno := @rowno + 1 AS rowno , m.sub_seconds, m.MAT_ROOT_NO, m.L4_STEELGRADE_ID , m.MAT_ID, m.FUR_NO FROM ( SELECT  c.SID,  c.MAT_ROOT_NO,  c.DISCH_TIME,  c.YIELD_TIMESTAMP,  c.L4_STEELGRADE_ID, c.MAT_ID,  TIMESTAMPDIFF( SECOND, STR_TO_DATE( e.DISCH_TIME, '%Y%m%d%H%i%s' ), STR_TO_DATE( c.DISCH_TIME, '%Y%m%d%H%i%s' ) ) sub_seconds , c.FUR_NO FROM  (  SELECT   a.*,   ( @i := @i + 1 ) AS ord_num  FROM   (   SELECT    p.SID,    p.MAT_ROOT_NO,    t.DISCH_TIME,    p.YIELD_TIMESTAMP,     p.L4_STEELGRADE_ID ,   p.MAT_ID,   (select FUR_NO   from qgcxm1_tmmhr19 tm where p.MAT_ROOT_NO = tm.IN_MAT_NO AND IN_OUT_FLAG = 2  AND  tm.DISCH_TIME=t.DISCH_TIME)FUR_NO   FROM    rzpes_pes_mat_material p    LEFT JOIN (SELECT IN_MAT_NO, max(DISCH_TIME) AS DISCH_TIME                FROM qgcxm1_tmmhr19                WHERE IN_OUT_FLAG = 2                GROUP BY IN_MAT_NO) t ON p.MAT_ROOT_NO = t.IN_MAT_NO   WHERE     p.YIELD_TIMESTAMP > DATE_FORMAT( CURRENT_DATE ( ), '%Y-%m-%d' )   and p.yield_eqpt_id='H21'   ) a,   ( SELECT @i := 1 ) b  ORDER BY   a.YIELD_TIMESTAMP DESC  ) c  LEFT JOIN (  SELECT   a1.*,   ( @j := @j + 1 ) AS ord_num  FROM   (   SELECT    p1.SID,    p1.MAT_ROOT_NO,    t1.DISCH_TIME,    p1.YIELD_TIMESTAMP   FROM    rzpes_pes_mat_material p1    LEFT JOIN (SELECT IN_MAT_NO, max(DISCH_TIME) AS DISCH_TIME                FROM qgcxm1_tmmhr19                WHERE IN_OUT_FLAG = 2                GROUP BY IN_MAT_NO) t1 ON p1.MAT_ROOT_NO = t1.IN_MAT_NO   WHERE     p1.YIELD_TIMESTAMP > DATE_FORMAT( DATE_SUB( CURRENT_DATE ( ), INTERVAL 1 DAY ), '%Y-%m-%d' ) and p1.yield_eqpt_id='H21'   ) a1,   ( SELECT @j := 0 ) d  ORDER BY   a1.YIELD_TIMESTAMP DESC  ) e ON c.ord_num = e.ord_num where FUR_NO=1 -- 1为炉次1；2为炉次2；3为炉次3 ) m, ( SELECT @rowno := 0 ) t  )  n   )m where   m.rowno in (1,2,3,4,5,6);