$sql="select * from pub_count where time>=".(time()-15*60);
改成这样试试
$sql="select * from pub_count where time>='".(time()-15*60)."'";
改成这样试试
$sql="select * from pub_count where time>='".(time()-15*60)."'";
可能是update操作失败了,我重新检查一下插入和修改语句,看哪里有问题