MySQL Query Error select id,title,subtitle,class from dx_kskm_news where class='参考书' and ejxk_id in ('085231','085201','085227','085234','085206','085213','085214','085207','085208','085211','085229','085204','085216','085238','085235','085210','085215','085236','085240','085212','085222','085203','085202','085230','085209','085237','085224','085226','085232','085233','085225','085239','085205','085218','085220','085228','085217','085219','085221','085223','085200') order by kskm desc limit -50,50 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\wwwroot\dddjyky\wwwroot\lanmu2.php on line 330