mysql - Laravel 多对多如何在 Eloquent 或查询构建器中形成查询

Question

从以下查询我得到了预期的结果:

SELECT *
    FROM rooms r
    JOIN amenities_room am 
      ON r.id = am.room_id 
    JOIN amenities a 
      ON am.amenities_id = a.id
     AND a.id IN (2,3)
GROUP BY r.id
  HAVING COUNT(*)=2;

我如何在(Eloquent 或 Query Builder 中)以 laravel 方式进行查询

注意:涉及以下表格:

房间
编号
号码
姓名

便利设施
编号
姓名

amenities_room
房间编号
amenities_id

Answer 1

$rooms = Room::with('amenities')
->withCount('amenities', function($query){
  $query->whereIn('id', [2, 3]);
})
->where('amenities_count', 2)
->get()

统计相关模型的文档:https://laravel.com/docs/5.5/eloquent-relationships#counting-related-models