Laravel HasMany Relation 返回所有模型，而不是相关模型

Question

我正在使用 Laravel 5.5，我有一个 Movie 模型:

  
    class Movie extends Model
    {
        public function comments(){
            return $this->hasMany(Comment::class);
        }
    }
 

and a Comment model:

class Comment extends Model
{
    public function movie(){
        return $this->belongsTo(Movie::class);
    }
}

我有一个电影实例(存储在 $movie 变量中):

id: "tt5726616",
     title: "Call Me by Your Name",
     original_title: "Call Me by Your Name",
     rate: 4,
     year: 2017,
     length: "132",
     language: "English, Italian, French, German",
     country: "Italy, France, Brazil, USA",
     director: "Luca Guadagnino",
     created_at: "2018-01-21 15:28:31",
     updated_at: "2018-01-21 15:28:31",

我有 4 条评论，其中 2 条与相应的电影相关:

all: [
       App\Comment {#788
         id: 1,
         movie_id: "tt3967856",
         author: "user1",
         comment: "cool!",
         rate: 2,
         created_at: "2018-01-21 15:28:32",
         updated_at: "2018-01-21 15:28:32",
       },
       App\Comment {#786
         id: 2,
         movie_id: "tt3967856",
         author: "user2",
         comment: "not bad!",
         rate: 3,
         created_at: "2018-01-21 15:28:32",
         updated_at: "2018-01-21 15:28:32",
       },
       App\Comment {#785
         id: 3,
         movie_id: "tt5726616",
         author: "user1",
         comment: "cool!",
         rate: 4,
         created_at: "2018-01-21 15:28:32",
         updated_at: "2018-01-21 15:28:32",
       },
       App\Comment {#784
         id: 4,
         movie_id: "tt5726616",
         author: "user2",
         comment: "not bad!",
         rate: 5,
         created_at: "2018-01-21 15:28:32",
         updated_at: "2018-01-21 15:28:32",
       },
     ],

问题是，当我调用 $movie->comments 时，它会返回我所有的 4 条评论，而不仅仅是那两 strip 有 movie_id tt3967856 的评论。我该怎么办？

已解决:我认为那是因为我在主键和外键中使用了字符串类型。我将 id 更改为整数(我的意思是 1,2,... 而不是“tt3967856”等)并且一切正常:D

Answer 1

如果指定外键和本地键怎么办

class Movie extends Model
{
   protected $casts=['movie_id'=>'integer'];

    public function comments(){
        return $this->hasMany(Comment::class,movie_id,id);
    }
}

更新:我还注意到 movie_id 在评论对象中有 string 类型

你应该把它转换成整数