MySQL Query Error select id,title,subtitle,class from dx_kskm_news where class='参考书' and ejxk_id in ('090602','090657','090659','090601','090603','090652','090654','090600','090661','090655','090658','090653','090656','090650','090660','090662','090663','090664') order by kskm desc limit -850,50 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\wwwroot\dddjyky\wwwroot\lanmu2.php on line 330