把session写到数据库中

 

一、将SESSION数据写入数据库中（使用PDO）

 

session_set_save_handler();

 

pdo 

 

1. 表设计 

 

2. 用类编写完成，写入数据库的表中session

 

3. 加入到实例中

 

 

类中各回调函数定义都要定义为静态方法，属性也要是静态的（静态成员使用）

 

 

        定义的表字段：SESSIONID， update_time, client_ip, data

 

 

 

2、具体程序代码

 

1、定义的保存到数据库的session类：session.class.php

<?php
class Session {
private static $handler=null;
private static $ip=null;
private static $lifetime=null;
private static $time=null;

private static function init($handler){
self::$handler=$handler;
self::$ip = !empty($_SERVER["REMOTE_ADDR"]) ? $_SERVER["REMOTE_ADDR"] : 'unknown';
self::$lifetime=ini_get('session.gc_maxlifetime');
self::$time=time();
}

static function start(PDO $pdo){
self::init($pdo);
session_set_save_handler(
array(__CLASS__,"open"),
array(__CLASS__,"close"),
array(__CLASS__,"read"),
array(__CLASS__,"write"),
array(__CLASS__,"destroy"),
array(__CLASS__,"gc")
);

session_start();
}

public static function open($path, $name){
return true;
}

public static function close(){
return true;
}

public static function read($PHPSESSID){
$sql="select PHPSESSID, update_time, client_ip, data from session where PHPSESSID= ?";

$stmt=self::$handler->prepare($sql);

$stmt->execute(array($PHPSESSID));

if(!$result=$stmt->fetch(PDO::FETCH_ASSOC)){
return '';
}

if( self::$ip  != $result["client_ip"]){
self::destroy($PHPSESSID);
return '';
}

if(($result["update_time"] + self::$lifetime) < self::$time ){
self::destroy($PHPSESSID);
return '';
}

return $result['data'];

}

public static function write($PHPSESSID, $data){
$sql="select PHPSESSID, update_time, client_ip, data from session where PHPSESSID= ?";

$stmt=self::$handler->prepare($sql);

$stmt->execute(array($PHPSESSID));

if($result=$stmt->fetch(PDO::FETCH_ASSOC)){
if($result['data'] != $data || self::$time > ($result['update_time']+30)){
$sql="update session set update_time = ?, data =? where PHPSESSID = ?";

$stm=self::$handler->prepare($sql);
$stm->execute(array(self::$time, $data, $PHPSESSID));

}
}else{
if(!empty($data)){
$sql="insert into session(PHPSESSID, update_time, client_ip, data) values(?,?,?,?)";

$sth=self::$handler->prepare($sql);

$sth->execute(array($PHPSESSID, self::$time, self::$ip, $data));
}
}

return true;
}

public static function destroy($PHPSESSID){
$sql="delete from session where PHPSESSID = ?";

$stmt=self::$handler->prepare($sql);

$stmt->execute(array($PHPSESSID));

return true;
}

private static function gc($lifetime){
$sql = "delete from session where update_time < ?";

$stmt=self::$handler->prepare($sql);

$stmt->execute(array(self::$time-$lifetime));

return true;
} 
}

try{
$pdo=new PDO("mysql:host=localhost;dbname=xsphpdb", "root", "123456");
}catch(PDOException $e){
echo $e->getMessage();
}

Session::start($pdo);
?>

 

 

2、session值定义页面：one.php

<?php
include "session.class.php";

$_SESSION["isLogin3"]=1;
$_SESSION["username"]="admin";
$_SESSION["uid"]=333;

echo session_name().'='.session_id().'<br>';
?>

 

 

3、从另外页面取值的页面：two.php

<?php
include "session.class.php";

print_r($_SESSION);
echo '<br>';

echo session_name().'='.session_id().'<br>';
?>

 

 

4、销毁页面：three.php

<?php
include "session.class.php";

$_SESSION=array();

if(isset($_COOKIE[session_name()])){
setCookie(session_name(), '', time()-100, '/');
}

session_destroy();

echo session_name().'='.session_id().'<br>';
?>