Question

共有3张桌子：

users：ID，名称

compliments：ID，名称

users_compliments：id，compliment_id，user_id，complimentor_id

这是我的用户模型：

class User extends Model
    public function sent_compliments()  {  
        return 
            $this->belongsToMany(
            'Compliment', 
            'users_compliments', 
            'complimentor_id',
            'compliment_id'
         )->withPivot('user_id');
}

如果我运行$user->sent_compliments()->get()

，这是示例响应

Illuminate\Database\Eloquent\Collection {
     all: [
       Compliment {
         id: 2,
         name: "You are smart",
         pivot: Illuminate\Database\Eloquent\Relations\Pivot {
           user_id: 6,
           id: 99,
         },
       },
       Compliment {
         id: 52,
         name: "You are funny",
         pivot: Illuminate\Database\Eloquent\Relations\Pivot {
           user_id: 42,
           id: 186,
         },
       },
     ],
   }

但这是我想要的响应（它包括实际的User模型，而不只是数据透视图中的user_id）

Illuminate\Database\Eloquent\Collection {
     all: [
       Compliment {
         id: 2,
         name: "You are smart",
         pivot: Illuminate\Database\Eloquent\Relations\Pivot {
           user_id: 6,
           id: 99,
         },
         user {
             id: 6,
             name: "John"
         }
       },
       Compliment {
         id: 52,
         name: "You are funny",
         pivot: Illuminate\Database\Eloquent\Relations\Pivot {
           user_id: 42,
           id: 186,
         },
           user {
             id: 42,
             name: "Alex"
         }
       },
     ],
   }

是否有一种方法可以使负载量大得多（例如使用With::命令）而不是遍历数据透视表，收集user_id和手动查询User表？ >

Answer 1

您需要定义pivot类并添加关系belongsTo来枢转user_id的模型

用户模型

public function sent_compliments()  {  
    return 
        $this->belongsToMany(
        'Compliment', 
        'users_compliments', 
        'complimentor_id',
        'compliment_id'
     )->withPivot('user_id')->using('App\UserComplement');
}

枢轴模型 使用Illuminate \ Database \ Eloquent \ Relations \ Pivot;

class UserComplement extends Pivot {
    protected $table = 'users_compliments';

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

人的数据

//if you have user instance already then
$complements = $user->sent_compliments;

//if you don't have fetched user yet then try this 
$user = User::with('sent_compliments')->find($userId);
$complements = $user->sent_compliments;

foreach($complements as $complement){
    dd($complement);
    dd($complement->pivot->user);
}

有关详细信息，请检查此定义自定义中间表模型 https://laravel.com/docs/5.6/eloquent-relationships#many-to-many

编辑

正如@JonasStaudenmeir指出的那样，没有办法渴望加载pivot user关系。这是另一种解决方案

用户模型

public function sent_compliments()  {  
    return $this->hasMany(UserCompliment::class , 'complimentor_id');
}

UserComplement模型

class UserComplement extends Model {
    $table = 'users_compliments';

    public function complimentor()  {  
        return $this->belongsTo(User::class , 'complimentor_id');
    }

    public function complement()  {  
        return $this->belongsTo(Compliment::class , 'compliment_id');
    }

    public function user()  {  
        return $this->belongsTo(User::class , 'user_id');
    }
}

获取数据

$user = User::with('sent_compliments','sent_compliments.complement', 'sent_compliments.user')->find($userId);
$sentComplements = $user->sent_compliments;

foreach($sentComplements as $sentComplement){
    dd($sentComplement->complement);
    dd($sentComplement->user);
}

希望它可能会让您明白

Laravel渴望具有hasMany关系的负载模型

1 个答案: