<?php
/**
* 修改session存放方式为Mysql Aboc QQ:9986584
*/

class Session{

//过期时间
private $_LEFT_TIME = 1440;

public function open() {


    }

public function close(){
    
}

/**
   * 读
   */
public function read( $sessid ) {
$sql = "select data from dm_session where sessid ='$sessid' and expiry > time()";
$row = DMmysql::open()->fetchRow( $sql );
return $row['data'];
}

/**
   * 写
   */
public function write( $sessid , $sessdata ) {
$data = array(
    'expiry'    =>   time()+ $this->_LEFT_TIME,
    'data'      =>   $sessdata,
    'ip'   =>   '192.168.1.123'
);
if( DMmysql::open()->fetchRow("select sessid from dm_session where sessid ='$sessid'") ) {
   //更新
   $where = "sessid = '$sessid'";
   if( DMmysql::open()->update( 'dm_session',$data,$where ) ){
    return true;
   } else {
    return false;
   }
} else {
   //插入
   $data['sessid'] = $sessid;
   if( DMmysql::open()->insert('dm_session',$data) ){
    return true;
   } else {
    return false;
   }   
}
}

/**
   * 指定销毁
   */
public function destroy( $sessid ) {
$where = "sessid = '$sessid'";
if(DMmysql::open()->delete('dm_session',$where)) {
   return true;
} else {
   return false;
}
}

/**
   * 销毁过期的数据
   */
public function gc( $maxlifetime ) {
//随机销毁数据,减轻服务器压力
if( rand(0,3) == 3 ) {
   $where = "expiry < time()";
   if( DMmysql::open()->delete('dm_session',$where) ) {
      return true;
   } else {
    return false;
   }
}
}

}

$session = new Session();
session_set_save_handler(
    array(&$session,'open'),
    array(&$session,'close'),
    array(&$session,'read'),
    array(&$session,'write'),
    array(&$session,'destroy'),
    array(&$session,'gc')
);
session_start();
?>

在每个使用session的文件前include一下就行了