正确的实现方式：DAO设计模式php+；pdo

例如：

class UserMapper {

    protected $db;

    public function __construct(PDO $db) {
        $this->db = $db;
    }

    public function save(User $user_object)
    {

    }


    public function getUserById($id)
    {
        //code
    }


}

class User {

    private $id;
    private $username;

    function __construct($user_row = null) 
    {
        if (!is_null($user_row)) {
            $this->id = $user_row->id;
            $this->username = $user_row->username;
        }
    }

    public function __set($name, $value)
    {
    }

    public function __get($name)
    {
        return $this->$name;
    }

}

---

这是实现模式的正确方法吗？

好吧，就这样了，但模式还有更多。您可能想查看这篇文章和参考资料，其中对模式进行了深入的解释

$user = new User();
$user->username = 'New Username';
$user_mapper = new UserMapper($db); //Pdo object = $db
$user_mapper->save($user);