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 (17,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199) AND catid IN (4,18,19,20,21,22,23,24,25,26,27,28,440,441) 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