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','701药学概论','802高分子材料','302数学二','899普通物理（材料院）','886材料科学基础','822材料化学','621物理化学','813高分子化学与物理','858材料学','338生物化学','888生物材料','802材料科学基础','704纳米材料技术','804材料科学基础','809物理化学','201英语一或203日语','833材料科学基础','616普通物理学','818材料科学基础') order by kskm desc limit -2250,50 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\wwwroot\dddjyky\wwwroot\lanmu.php on line 331
