如何通过多态关系将关系写入到远程模型

Question

我有一个多态关系，其中类（请求）可以与类（离开）或类（加班）有关系。

类 (Request) 的每个对象都属于一个用户。

我想在 User 类中建立一个关系来直接获取他们所有的 Leave 或 Overtime 对象。

---

代码如下：

• 类请求：
  • user_id
  • requestable_id
  • requestable_type 可以是 App\Leave 或 App\Overtime

    class Request extends Model
    {
        public function requestable() {
            return $this->morphTo();
        }

        public function user() {
            return $this->belongsTo('App\User');
        }
    }

• 课假

    class Leave extends Model
    {
        public function request() {
            return $this->morphOne('App\Request', 'requestable');
        }
    }

• 上课加班

    class Overtime extends Model
    {
        public function request() {
            return $this->morphOne('App\Request', 'requestable');
        }
    }

• 类用户

    class User extends Authenticatable
    {
        public function requests() {
            return $this->hasMany(Request::class);
        }

        public function leaves() {
            // Need help here
        }

        public function overtimes() {
            // And here
        }
    }

---

我想做的是获得用户的所有休假和加班，所以最终我应该能够做到这一点：

    $userLeaves = $user->leaves;
    $userOvertimes = $user->overtimes;

Answer 1

似乎您需要多态关系（您已经定义）和 hasManyThrough 的组合。 return $this->hasManyThrough(Leave::class, Request::class); 和 return $this->hasManyThrough(Overtime::class, Request::class); 分别。但是检查外键和本地键（查看更多信息here）。

Answer 2

您可以通过用户请求获取用户休假和加班使用

$requests = $user->requests->with('requestable');

但这将获取所有用户请求，而不取决于类型，但是您可以根据需要使用叶子和超时函数根据类型获取它们并在此处指定类型

用户类

public function leaves()
{
    return $this->requests->where('requestable_type', 'App\Leave');
}

public function overTimes()
{
    return $this->requests->where('requestable_type', 'App\OverTime');
}

Answer 3

回答我自己的问题。

使用hasManyThrough：

public function leaves() {
    return $this->hasManyThrough(
        Leave::class, // the class that we want objects from
        Request::class, // the class sitting between this one and the target
        'user_id', // this class's foreign key in the request class
        'id', // foreign key in leave class
        'id', // local key in this class
        'requestable_id' // key of the leave in the request class
        )
        // we have to limit it to only Leave class
        ->where('requestable_type', array_search(Leave::class, Relation::morphMap()) ?: Leave::class);
}

public function overtimes() {
    return $this->hasManyThrough(
        Overtime::class, // the class that we want objects from
        Request::class, // the class sitting between this one and the target
        'user_id', // this class's foreign key in the request class
        'id', // foreign key in overtime class
        'id', // local key in this class
        'requestable_id' // key of the overtime in the request class
        )
        // we have to limit it to only overtime class
        ->where('requestable_type', array_search(Overtime::class, Relation::morphMap()) ?: Overtime::class); 
}