MySQL Query Error select id,title,subtitle,class from dx_kskm_news where class='参考书' and ejxk_id in ('060200','060252','060250','060201','060204','060205','060206','060203','060202','060262','060251','060269','060268','060265','060253','060266','060254','060263','060270','060275','060271','0602J2','060274','060276','60200','0602J1','060273','0602L4','0602L5','0602Z1','0602Z3') order by kskm desc limit -2250,50 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\wwwroot\dddjyky\wwwroot\lanmu2.php on line 330