<?php

$wherelist=array();

if(!empty($_GET['sid']))

{

$wherelist[]=" sid like '%".$_GET['sid']."%'"; 

}

if(!empty($_GET['sname']))

{

$wherelist[]=" sname like '%".$_GET['sname']."%'";

}if(!empty($_GET['ssex']))

{

$wherelist[]=" ssex like '%".$_GET['ssex']."%'";

}

$where="";

if(count($wherelist)>0)

{

$where=" where ".implode(' and ',$wherelist);//implode 把数组元素组合为字符串

}

//分页的实现原理

//1.获取数据表中总记录数

$sql="select * from student  $where "; 

$result=mysql_query($sql);

$totalnum=mysql_num_rows($result);

//每页显示条数

$pagesize=8;

//总共有几页

$maxpage=ceil($totalnum/$pagesize);

$page=isset($_GET['page'])?$_GET['page']:1;//isset函数是检测变量是否设置。

if($page <1)

{

$page=1;

}

if($page>$maxpage)

{

$page=$maxpage;

}

$limit=" limit ".($page-1)*$pagesize.",$pagesize";//显示当前页

$sql0="select yhouse from yuangong where yid='{$_COOKIE['a']}'";

$rs0=mysql_query($sql0,$link);

$row0=mysql_fetch_assoc($rs0);

$yh=$row0['yhouse'];

$sql1="select * from student $where order by sid desc $limit"; //此处加了id降序

$res=mysql_query($sql1);

?>

为甚么我$sql1="select * from student where $yh=shourse $where order by sid desc $limit"; 变成这样搜索功能就不行了呢？求帮忙谢谢你们！