123/www/wwwroot/xunxuetang.cn/include/db_mysqli.class.phpSELECT itemid,title,thumb,linkurl,style,catid,areaid,introduce,addtime,edittime,username,company,groupid,vip,qq,wx,ali,skype,validated,price,unit,minamount,amount FROM xxt_sell_5 WHERE status=3 AND areaid IN (21,252,253,254,255,256,257,258,259,260,261,262,263,264,265) AND catid IN (6,41,42,43,44,45,426,427) order by itemid desc LIMIT -20,20You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '-20,20' at line 1