返回空数组的雄辩关系

我是新来的拉勒维尔,我正在努力实现一些非常基本的东西,但仍然陷入困境。

我有两个模型,post.php和like.php

我正在尝试使用雄辩的关系获取所有链接到帖子的赞,但它返回的是一个空数组。这是我的密码-

post.php后

public function likes(){
  return $this->hasMany('App\Like');
}

route.php路径

Route::get('/', function(){
  $posts = Post::all()->sortByDesc("post_id");
  return view('index')->with(['posts' => $posts]);
});

view.blade.php视图

@foreach($posts as $post)
  {{ $post->likes }}
@endforeach

我在这里做错什么了?

更新- 喜欢表迁移

public function up()
{
    Schema::create('likes', function (Blueprint $table) {
        $table->increments('like_id');
        $table->integer('post_id')->unsigned();
        $table->integer('user_id')->unsigned();
        $table->foreign('post_id')->references('post_id')->on('posts')->onDelete('cascade');
        $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
        $table->timestamps();
    });
}

迁移后

public function up()
{
    Schema::create('posts', function (Blueprint $table) {
        $table->increments('post_id');
        $table->integer('user_id')->unsigned();
        $table->string('post_message');
        $table->timestamps();
        $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
    });
}

后置模型

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Post extends Model
{

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

  public function likes(){
    return $this->hasMany('App\Like');
  }
}