我创建了三个模型，分别是Post、Comment和User。我试图在两者之间建立一种关系。Comment和Post都有一个字段“user\u id”，与user表上的id匹配。以下是我正在尝试设置的关系：

Comment.php：

<?php

namespace App;


class Comment extends Model
{
    //
    public function post(){

        return $this->belongsTo(Post::class);
    }



    public function user(){ 

        return $this->belongsTo(User::class);
    }
}

邮递php:

<?php

namespace App;

class Post extends Model
{

    public function comments(){

        return $this->hasMany(Comment::class);
    }

    public function addComment($body, $name, $email){




        $this->comments()->create(compact('body','name','email'));
    }

       public function user(){ // $comment->user->name

        return $this->belongsTo(User::class);
    }
}

使用者php

    <?php

namespace App;
use App\Post;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];

    public function post(){

        return $this->hasMany(Post::class);
    }



}

现在，您可以看到一个评论属性给用户和一个帖子属性给用户。

然而，当我试图通过tinker创建一个新帖子时（没有在数据库上创建用户或登录用户），我可以创建一个没有问题的帖子；

这告诉我，一篇文章必须有一个用户，一篇评论也必须有一个用户，这种关系不起作用！你知道怎么解决这个问题吗？

迁移：

创建\u帖子\u迁移：

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreatePostsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('posts', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('user_id');
            $table->string('title');
            $table->text('body');
            $table->string('image');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('posts');
    }
}

创建\u注释\u迁移：

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateCommentsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('comments', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('post_id');
            $table->integer('user_id');
            $table->string('email');
            $table->string('name');
            $table->string('body');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('comments');
    }
}