如何通过多态关系将关系写到远程模型

Question

我有一个多态关系，其中类（请求）可以与类（离开）或类（超时）有关系。

类（请求）的每个对象都属于一个用户。

我想在User类中设置一个关系，以直接获取其所有的Leave或Overtime对象。

---

代码如下所示：

• 课堂要求：
  • 用户身份
  • 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');
        }
    }

• 上课假

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

• 班级加班

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

• 班级用户

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

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

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

---

我想做的就是让用户拥有所有的假期和加班时间，因此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（已经定义）和hasManyThrough的组合。 return $this->hasManyThrough(Leave::class, Request::class); 并return $this->hasManyThrough(Overtime::class, Request::class); 分别。 但是请检查外键和本地键（ 在此处查看更多信息）。

Answer 2

您可以使用来通过用户请求获取用户休假和加班

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

但这将获取不依赖于类型的所有用户请求，但是，如果需要，您可以通过使用leaves and overtimes函数并在其中指定类型来获取依赖于类型的所有用户请求。

用户类别

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); 
}