MySQL Query Error select id,title,subtitle,class from dx_kskm_news where class='参考书' and ejxk_id in ('080800','080850','080802','080803','080804','080805','080801','080859','080864','080868','080867','080863','080854','080857','080852','080855','080860','080861','080856','080862','080851','080869','080871','080870','080873','080866','080872','80800','80804','0808J3','0808J1') order by kskm desc limit -2000,50 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\wwwroot\dddjyky\wwwroot\lanmu2.php on line 330