MySQL Query Error select id,title,subtitle,class from dx_kskm_news where class='参考书' and ejxk_id in ('090402','090401','090455','090403','090460','090461','090466','090459','090457','090400','090454','090458','090464','090450','090452','090467','090453','090465','090468','090469','0904J1') order by kskm desc limit -150,50 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\wwwroot\dddjyky\wwwroot\lanmu2.php on line 330