PHP PDO - 无法序列化或反序列化PDO实例

Question

我需要将一个PDO连接传递给一个cart类controller,

function __construct($connection) 
{
    $this->cart = new cart($connection);
}

但我认为问题在于 serialize()

public function render_page() 
{

    if (!isset($_SESSION[SESSION_CART]))
    {
       $cart =  $this->cart;
    }
    else 
    {
       $cart = unserialize($_SESSION[SESSION_CART]);
    }

    $_SESSION[SESSION_CART] = serialize($cart); 

 }

我收到这个错误,

致命错误:C:\ wamp\www\store_2012_MVC\local\controllers\class_base_extended_cart.php中带有消息'您无法序列化或反序列化PDO实例'的未捕获异常'PDOException':89堆栈跟踪:#0 [内部函数]:PDO- > __ sleep()#1 C:\ wamp\www\store_2012_MVC\local\controllers\class_base_extended_cart.php(89):serialize(Object(cart))#2 C:\ wamp\www\store_2012_MVC\local\controllers\class_factory. php(75):base_extended_cart-> render_page()#3 C:\ wamp\www\store_2012_MVC\index.php(69):factory-> render()#4 {main}抛出C:\ wamp\www\store_2012_MVC第89行的\ local\controllers\class_base_extended_cart.php

我怎样才能解决这个问题？

或者我可以使用别的东西而不是serialize()？

编辑:

我尝试了 __sleep和__wakeup魔术方法,但仍然得到相同的错误,

class database_pdo
{
    # database handler
    protected $connection = null;

    # make a connection
    public function __construct($dsn,$username,$password)
    {
        try 
        {

            $this->connection = new PDO($dsn, $username, $password, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));
            $this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 

        }
        catch (PDOException $e) 
        {
            # call the get_error function
            $this->get_error($e);
        }
    }

    # don't forget to add getter method to get $this->connection, it's just a good practice.
    public function get_connection()
    {
        return $this->connection;
    }

    public function __sleep()
    {
        return array('connection');
    }

    public function __wakeup()
    {
        $this->connection;
    }

}

Answer 1

看一下 __sleep 和 __wakeup 魔术方法。 http://us.php.net/manual/en/language.oop5.magic.php#object.sleep

它们允许您指定哪些属性被序列化以及哪些属性被忽略。问题是您需要定期传入 PDO 对象的实例。