我不断得到这样的错误：“错误1064：你的sql语法有错误；请查看与您的mysql服务器版本对应的手册，以获取正确的语法，以便使用ord\ U success s中的near'（order by processdate desc）rwn，s.serno，其中ga'位于第5行“

CREATE  PROCEDURE move_sucess_order(p_gwserno DOUBLE, p_mindate DOUBLE, p_keepsize DOUBLE)
BEGIN
DECLARE NOT_FOUND INT DEFAULT 0;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET NOT_FOUND = 1;
   DECLARE rec CURSOR FOR SELECT serno FROM ( SELECT row_number() OVER(ORDER BY processdate DESC) rwn,  s.serno
       FROM ord_success s WHERE gatewayserno = p_gwserno AND processdate < p_mindate
       ) t WHERE rwn > p_keepsize; OPEN rec;
 FETCH rec INTO;
 WHILE NOT_FOUND=0
 DO
 INSERT INTO ord_success_arc
    SELECT serno, gatewayserno, targetserno, meterpointserno, mastermessagetype,
         messagetype, rawcontent, createdate, createuser, createtransactionid, requesttype, processtype,
         lastexecutorendpoint, orderstatus, bidirectedserno, externalherefno, processtarget, isasync, processdate,
         lpstartdate, lpenddate, updatedate, updateuser, updatetransactionid, recordstatus, externalsdmsource, externalsdmserno
     FROM ord_success WHERE serno = rec.serno;
     DELETE FROM ord_success WHERE serno = rec.serno;

    FETCH  INTO;
    END WHILE;
    CLOSE ;

我是mysql的新手。我仔细检查了mysql手册。但我想不出怎么解决这个问题。谢谢你的帮助。