通過(guò)session_set_save_handler(string open,string close,string read,string write,string destory,string gc)鳍贾。

(1)open(save path ,session_name)----找到session存儲(chǔ)的地址，
(2)close()------關(guān)閉數(shù)據(jù)庫(kù)
(3)read(key)-------讀取session值蕉饼，key對(duì)應(yīng)session_id
(4)write(key,data)------data對(duì)應(yīng)設(shè)置的session變量
(5)destory(key)------注銷session對(duì)應(yīng)的
(6)gc(expriy_time)------清除過(guò)期的session
簡(jiǎn)單應(yīng)用

<?php
$con = mysql_connect("127.0.0.1", "user" , "pass");
mysql_select_db("session");
function open($save_path, $session_name) {
    return(true);
}
function close() {
    return(true);
}
function read($id) {
    if ($result = mysql_query("select * from session where id='$id'")) {
        if ($row = mysql_felth_row($result)) {
            return $row["data"];
        }
    } else {
        return "";
    }
}
function write($id, $sess_data) {
    if ($result = mysql_query("update session set data='$sess_data' where id='$id'")) {
        return true;
    } else {
        return false;
    }
}
function destroy($id) {
    if ($result = mysql_query("delete * from session where id='$id'")) {
        return true;
    } else {
        return false;
    }
}
function gc($maxlifetime) {
    return true;
}
session_set_save_handler("open", "close", "read", "write", "destroy", "gc");
session_start();
// proceed to use sessions normally

實(shí)際案例

<?php
/**
 * SessionMysql 數(shù)據(jù)庫(kù)存儲(chǔ)類
 */

defined('IN_QIAN') or exit('Access Denied');

class SessionMysql {

    public $lifetime = 1800; // 有效期拷泽，單位：秒（s）贺待，默認(rèn)30分鐘
    public $db;
    public $table;

    /**
     * 構(gòu)造函數(shù)
     */
    public function __construct() {
        $this->db = Base::loadModel('SessionModel');
        $this->lifetime = Base::loadConfig('system', 'session_lifetime');
        session_set_save_handler(
            array(&$this, 'open'),      // 在運(yùn)行session_start()時(shí)執(zhí)行
            array(&$this, 'close'),     // 在腳本執(zhí)行完成 或 調(diào)用session_write_close() 或 session_destroy()時(shí)被執(zhí)行，即在所有session操作完后被執(zhí)行
            array(&$this, 'read'),      // 在運(yùn)行session_start()時(shí)執(zhí)行，因?yàn)樵趕ession_start時(shí)除抛，會(huì)去read當(dāng)前session數(shù)據(jù)
            array(&$this, 'write'),     // 此方法在腳本結(jié)束和使用session_write_close()強(qiáng)制提交SESSION數(shù)據(jù)時(shí)執(zhí)行
            array(&$this, 'destroy'),   // 在運(yùn)行session_destroy()時(shí)執(zhí)行
            array(&$this, 'gc')         // 執(zhí)行概率由session.gc_probability 和 session.gc_divisor的值決定薯酝，時(shí)機(jī)是在open半沽，read之后，session_start會(huì)相繼執(zhí)行open吴菠，read和gc
        );
        session_start(); // 這也是必須的者填，打開session，必須在session_set_save_handler后面執(zhí)行
    }
    /**
     * session_set_save_handler open方法
     *
     * @param $savePath
     * @param $sessionName
     * @return true
     */
    public function open($savePath, $sessionName) {
        return true;
    }
    /**
     * session_set_save_handler close方法
     *
     * @return bool
     */
    public function close() {
        return $this->gc($this->lifetime);
    }
    /**
     * 讀取session_id
     *
     * session_set_save_handler read方法
     * @return string 讀取session_id
     */
    public function read($sessionId) {
        $condition = array(
            'where' => array(
                'session_id' => $sessionId
            ),
            'fields' => 'data'
        );
        $row = $this->db->fetchFirst($condition);
        return $row ? $row['data'] : '';
    }
    /**
     * 寫入session_id 的值
     *
     * @param $sessionId 會(huì)話ID
     * @param $data 值
     * @return mixed query 執(zhí)行結(jié)果
     */
    public function write($sessionId, $data) {
        $userId = isset($_SESSION['userId']) ? $_SESSION['userId'] : 0;
        $roleId = isset($_SESSION['roleId']) ? $_SESSION['roleId'] : 0;
        $grouId = isset($_SESSION['grouId']) ? $_SESSION['grouId'] : 0;
        $m = defined('ROUTE_M') ? ROUTE_M : '';
        $c = defined('ROUTE_C') ? ROUTE_C : '';
        $a = defined('ROUTE_A') ? ROUTE_A : '';
        if (strlen($data) > 255) {
            $data = '';
        }
        $ip = get_ip();
        $sessionData = array(
            'session_id'    => $sessionId,
            'user_id'       => $userId,
            'ip'            => $ip,
            'last_visit'    => SYS_TIME,
            'role_id'       => $roleId,
            'group_id'      => $grouId,
            'm'             => $m,
            'c'             => $c,
            'a'             => $a,
            'data'          => $data,
        );
        return $this->db->insert($sessionData, 1, 1);
    }
    /**
     * 刪除指定的session_id
     *
     * @param string $sessionId 會(huì)話ID
     * @return bool
     */
    public function destroy($sessionId) {
        return $this->db->delete(array('session_id' => $sessionId));
    }
    /**
     * 刪除過(guò)期的 session
     *
     * @param $lifetime session有效期（單位：秒）
     * @return bool
    */
    public function gc($lifetime) {
        $expireTime = SYS_TIME - $lifetime;
        return $this->db->delete("`last_visit`<$expireTime");
    }
}