//////使用MySQL保存會話首先要創(chuàng)建session表：
<?php
$hostname_login = "localhost"; // Server address
$username_login = "root"; // User name 
$password_login = ""; // Password
//
$data_name = "session"; // Database name
$login = mysql_pconnect($hostname_login, $username_login, $password_login) or trigger_error(mysql_error(),E_USER_ERROR); 
$sql="SHOW DATABASES LIKE '".$data_name."'"; // If it is exist
if($rs_table=mysql_query($sql,$login)) { 
 if($rs_value=mysql_fetch_array($rs_table)) { 
  echo "數(shù)據(jù)庫已經(jīng)存在！\n!";
  exit(); 
 } 
}
$sql="CREATE DATABASE $data_name";  
mysql_query($sql); // Crate database
echo "數(shù)據(jù)庫創(chuàng)建成功！\n"; 
mysql_select_db($data_name, $login);
$sql="CREATE TABLE `sessions` ( 
`SessionKey` varchar(32) NOT NULL default '', 
`SessionArray` blob NOT NULL, 
`SessionExpTime` int(20) unsigned NOT NULL default '0', 
PRIMARY KEY (`SessionKey`), 
KEY `SessionKey` (`SessionKey`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8"; //新建數(shù)據(jù)庫 sql語句
mysql_query($sql);
echo "成功新建數(shù)據(jù)庫表！";
?>

/////////MysqlSession 類如下：
<?php 
class MysqlSession {
// 注意在有使用Session的頁面。頁面一定要頂格，頁面開始處不能留空。
private $DB_SERVER = "localhost"; // 數(shù)據(jù)庫服務器主機名
 private $DB_NAME = ""; // 數(shù)據(jù)庫名字
 private $DB_USER = "root";  // MYSQL 數(shù)據(jù)庫訪問用戶名 
 private $DB_PASS = "";  // MYSQL 數(shù)據(jù)庫訪問密碼 
 private $DB_SELECT_DB = ""; 
//private $SESS_LIFE = 1440;  // Session的最大使用時長，單位秒。
private $SESS_LIFE = 0;
function MysqlSession (&$sessionDB) {
 //session_write_close();
 $this->DB_NAME = &$sessionDB;
 $this->SESS_LIFE = get_cfg_var("session.gc_maxlifetime");
 session_module_name('user');
 session_set_save_handler( 
 array(&$this, 'sess_open'), 
 array(&$this, 'sess_close'), 
 array(&$this, 'sess_read'), 
 array(&$this, 'sess_write'), 
 array(&$this, 'sess_destroy'), 
 array(&$this, 'sess_gc') 
 );
 session_start();
}
function sess_open($save_path, $session_name){ // 打開數(shù)據(jù)庫連接
 if (! $this->DB_SELECT_DB = mysql_pconnect($this->DB_SERVER, $this->DB_USER, $this->DB_PASS)) { 
 echo "SORRY! MYSQL ERROR : Can't connect to $this->DB_SERVER as $DB_USER"; 
 echo "MySQL Error: ", mysql_error(); 
 die; 
 } 
 if (! mysql_select_db($this->DB_NAME, $this->DB_SELECT_DB)) { 
 echo "SORRY! MYSQL ERROR : Unable to select database $this->DB_NAME"; 
 die; 
 } 
 return true; 
} 
function sess_close() { 
  return true; 
} 
function sess_read($SessionKey){ 
  $Query = "SELECT SessionArray FROM sessions WHERE SessionKey = '".$SessionKey."' AND SessionExpTime > " . time();
  // 過期不讀取。
  $Result = mysql_query($Query, $this->DB_SELECT_DB); 
 if (list($SessionArray) = mysql_fetch_row($Result)) { 
   return $SessionArray; 
 } 
 return false; 
} 
function sess_write($SessionKey, $VArray) { 
 $SessionExpTime = time() + $this->SESS_LIFE;
 // 更新Session過期時間，
 //Session過期時間 = 最后一次更新時間 + Session的最大使用時長
 $SessionArray = addslashes($VArray); 
 $Query = "INSERT INTO sessions (SessionKey,SessionExpTime,SessionArray) VALUES ('".$SessionKey."','".$SessionExpTime."','".$SessionArray."')"; 
 $Result = mysql_query($Query, $this->DB_SELECT_DB); 
 if (!$Result){ 
   $Query = "UPDATE sessions SET SessionExpTime = '".$SessionExpTime."', SessionArray = '".$SessionArray."' WHERE SessionKey = '".$SessionKey."' AND SessionExpTime > " . time(); 
   $Result = mysql_query($Query, $this->DB_SELECT_DB); 
 } 
 return $Result; 
} 
function sess_destroy($SessionKey) { 
 $Query = "DELETE FROM sessions WHERE SessionKey = '".$SessionKey."'"; 
 $Result = mysql_query($Query, $this->DB_SELECT_DB); 
 return $Result; 
} 
function sess_gc($maxlifetime) {
// 這個垃圾清除器系統(tǒng)調用。
//默認是1440秒清除一次。參數(shù)可以在PHP.ini里面設置。
 $Query = "DELETE FROM sessions WHERE SessionExpTime < " . time(); 
 $Result = mysql_query($Query, $this->DB_SELECT_DB); 
 return mysql_affected_rows($this->DB_SELECT_DB); 
} 
}
?>
//用法：在原來使用 session_start 的地方，替換成 $session = new MysqlSession () 
//注意：包含此程序前要打開數(shù)據(jù)庫，主程序退出前不能關閉數(shù)據(jù)庫，否則會出錯。