Laravel 如何更改即时加载的连接？

这些是我的模型

class Posts extends Model {
    protected $connection = 'connection_1';

    public function comments()
    {
        $model = new Comments();
        $model->setConnection($this->connection);

        return $this->hasMany($model, 'comments_id');
    }

}

class Comments extends Model {
    protected $connection = 'connection_1';

    public function author()
    {
        $model = new Authors();
        $model->setConnection($this->connection);

        return $this->hasOne($model, 'id', 'authors_id');
    }

    public function post()
    {
        $model = new Posts();
        $model->setConnection($this->connection);

        return $this->hasOne($model, 'id', 'posts_id');
    }

}

class Authors extends Model {
    protected $connection = 'connection_1';

    public function comments()
    {
        $model = new Comments();
        $model->setConnection($this->connection);

        return $this->hasMany($model, 'authors_id');
    }

}

当我将此代码放入控制器时，注释模型连接到连接_2，但作者为空，我猜它不会将连接更改为连接_2

$posts = new Posts;
$posts->setConnection('connection_2');
$posts->load("comments.author")->get();

---

如何更改dinamically Authors模型连接，或者为什么Authors为空？

我已解决了以下问题：

$conn   = \App\Helpers\Helper::connection($item_id);
$newPdo = \DB::connection($conn)->getPdo();
\DB::setPdo($newPdo);

$posts = \App\Posts::with("comments.author")->get();

还有我的助手

public static function connection($project) {
    switch($project) {
        case 01:
            return 'connection_01';
        break;
        case 02:
            return 'connection_02';
        break;
        case 03:
            return 'connection_03';
        break;
    }
} 

---

我已经这样解决了我的问题：

$conn   = \App\Helpers\Helper::connection($item_id);
$newPdo = \DB::connection($conn)->getPdo();
\DB::setPdo($newPdo);

$posts = \App\Posts::with("comments.author")->get();

还有我的助手

public static function connection($project) {
    switch($project) {
        case 01:
            return 'connection_01';
        break;
        case 02:
            return 'connection_02';
        break;
        case 03:
            return 'connection_03';
        break;
    }
}