php怎么把session保存到MySql数据库中-PHP源码-php.cn

php怎么把session保存到MySql数据库中

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Release： 2016-06-08 17:22:36

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session我们多半是保存在服务器中呀，但是今天有一个功能就是需要把session保存在数据库中，这样可以实现同ie多浏览了，下面我们一起来看具体实现例子。

php中session默认的存储方式是硬盘，php也可以改变默认的存储方式。
主要使用到session_set_save_handler方法，下面分享下如何将session保存到MySql数据库中的具体代码。

1.建session表

代码如下	复制代码
CREATE TABLE `session` ( `sessionid` varchar(128) NOT NULL, `uid` int(11) NOT NULL, `data` mediumblob NOT NULL, `timestamp` int(11) NOT NULL, `ip` varchar(15) NOT NULL, PRIMARY KEY (`sessionid`), KEY `time_session` (`timestamp`,`sessionid`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8;

uid 是保留字段

2.自定义session类

代码如下

复制代码

class CustomSession{
private static $db_host="localhost";
private static $db_user="root";
private static $db_password="";
private static $database="session";

private $conn;

public static function getInstance(){
  static $instance=null;
  if($instance==null){
   $instance=new CustomSession();
  }

return $instance;
}

public function __construct(){
  session_set_save_handler(
  array($this,"open"),
  array($this,"close"),
  array($this,"read"),
  array($this,"write"),
  array($this,"destroy"),
  array($this,"gc")
  );
}

public function __destruct(){
session_write_close();
}

public function open(){
$this->conn=mysql_connect(CustomSession::$db_host,CustomSession::$db_user,CustomSession::$db_password);
mysql_select_db(CustomSession::$database,$this->conn);
}

public function close(){

mysql_close($this->conn);
}

public function read($id){
  $escaped_id=mysql_escape_string($id);
  $res=$this->query("select * from `session` where `sessionid`='$escaped_id'");
  if($row=mysql_fetch_assoc($res)){
   $this->query("update `session` set `timetamp`=UTC_TIMESTAMP() where `sessionid`='$escaped_id'");
   return $row['data'];
  }
  return "";
}

public function write($id,$data){
$query="replace into `session` (`sessionid`,`data`,`ip`,`timestamp`) values ('%s','%s','%s',UNIX_TIMESTAMP(UTC_TIMESTAMP()))";
$this->query(sprintf($query,mysql_escape_string($id),mysql_escape_string($data),$_SERVER["REMOTE_ADDR"]));//www.111cn.net
}

public function destroy($id){
  $escaped_id=mysql_escape_string($id);
  $res=$this->query("delete from `session` where `id`='$escaped_id'");
  return (mysql_affected_rows($res)==1);
}

public function gc($lifetime){
$this->query("delete from `session` where UNIX_TIMESTAMP(UTC_TIMESTAMP())-`timestamp` > $lifetime");
}

public function query($query){
$res=mysql_query($query,$this->conn);
return $res;
}
}

3.测试程序

代码如下

复制代码

include('./CustomSession.class.php');

CustomSession::getInstance();

session_start();

$_SESSION['username']='feng';

print_r($_SESSION);

运行测试程序后，查看数据库可以发现session表中已经增加了session记录