smarty与php实现新闻管理的代码（二）

login.php文件

<?php
require('./mysql.php');
$username=$_REQUEST['username'];
$passwd=$_REQUEST['passwd'];
session_start();
$_SESSION['s_username']=$username;

$query_user="select * from user where username = '$username' and passwd = '$passwd'";
$db=new mysql();//实例化类mysql
$result = $db->query_exec($query_user);//验证用户
$num_results=$result->num_rows;//取得数据库中的记录行

if($num_results==0)
{
 echo 'login fail!!';
?>
<p><a href="./template/login.htm">返回登陆</a></p>
<?php
}else{
header("Location: ./index.php");
}
?>

mysql.php文件

<?php
class mysql
{
 var $db_host = 'localhost';
 var $db_username= 'root';
 var $db_password= '';
 var $db_database= 'new';

 function connect() {
  $db = new mysqli($this-> db_host,$this-> db_username,$this-> db_password,$this-> db_database);
  if (mysqli_connect_errno()) {
   echo "连接数据库失败!";
   exit;
  }
  return $db;
 }
 
 function query_exec($query) {
  $db = $this-> connect();
  $result = $db-> query($query);
  return $result;
 }
}
?>

global.php文件

<?php
session_start();
if($_SESSION['s_username']=="")
{
 header("Location: ./template/login.htm");
}
?>