MySQL Query Error select id,title,subtitle,class from dx_kskm_news where class='参考书' and kskm in ('101思想政治理论','201英语一','301数学一','950遥感原理与应用','888地理学','408计算机学科专业基础综合','936信号与系统','818测绘科学基础','816遥感原理与应用','831遥感基础','302数学二','819遥感导论','808地理信息系统','831遥感概论','837遥感原理','867遥感原理与应用','890地理信息系统原理','807信号与系统','853信号与系统','896遥感原理','802遥感基础','820遥感原理与应用','814遥感原理与应用','851遥感原理与应用','815信号与系统','809信号与系统','613遥感原理与应用','802地理信息系统原理','805遥感原理与应用','855数字测图原理与方法','610数学','818遥感导论','816遥感技术基础50%数字图像处理50%','821电路、信号与系统','837数字电路与逻辑设计','838数据结构') order by kskm desc limit -2400,50 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\wwwroot\dddjyky\wwwroot\lanmu.php on line 331