用户和评论之间的雄辩关系

Question

使用Mac、Php版本7.1.19、最新版本的Laravel和SQLite数据库。该网站有3个模型。用户、评论和帖子。我想将评论连接到用户。这样人们就可以在仪表板上看到自己的评论。数据库应正确设置，注释表具有['id'、'user\u id'、'body'、'created\u at'、'updated\u at']。tinker错误告诉我它需要一个返回，但我为这两个函数都添加了一个返回。

你能详细说明我目前做错了什么吗？

在User.php中，我放置了一个comments函数。

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Notifications\Notifiable;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Foundation\Auth\User as Authenticatable;
use App\Comment;

class User extends Authenticatable
{


  use Notifiable;

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

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


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

/**
 * The attributes that should be cast to native types.
 *
 * @var array
 */
protected $casts = [
    'email_verified_at' => 'datetime',
];
}

在Comment.php中，我放置了一个用户函数。

<?php

namespace App;

use App\User;
use Illuminate\Database\Eloquent\Model;

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

更新，请求的数据库模型代码：

<?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->bigIncrements('id');
            $table->unsignedInteger('user_id');
            $table->string('body');
            $table->timestamps();
        });
    }

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

用户迁移代码：

<?php

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

class CreateUsersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('users', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('firstname');
            $table->string('lastname');
            $table->integer('age');
            $table->string('email')->unique();
            $table->timestamp('email_verified_at')->nullable();
            $table->string('password');
            $table->integer('isAdmin')->default(0);
            $table->rememberToken();
            $table->timestamps();
        });
    }

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

使用Php Artisan Tinker时，系统显示以下错误：

应用\用户::first（）-

Answer 1

数据库模型添加与用户表的关系

<?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->bigIncrements('id');

            $table->unsignedInteger('user_id');
            $table->foreign('user_id')->references('id')->on('users');

            $table->string('body');
            $table->timestamps();
        });
    }

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

User.php模型中的更改注释方法

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