MySQL Query Error select id,title,subtitle,class from dx_kskm_news where class='参考书' and ejxk_id in ('082300','082302','082301','082303','082304','082350','082351','082366','082365','082361','082364','082359','082360','082355','082354','082357','082367','082353','082356','082363','082368','082369','082370','082362','082377','082372','082352','082358','082376','82304','82301','82302','82303','0823Z1','0823Z5') order by kskm desc limit -1300,50 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\wwwroot\dddjyky\wwwroot\lanmu2.php on line 330