Question

我有三个模型，我创建了帖子和评论以及用户。我想在两者之间建立一种关系。注释和发布它们都有一个字段“user_id”，它匹配User表上的id。以下是我要设置的关系：

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);
    }
}

post.php中：

<?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);
    }
}

User.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);
    }



}

现在您可以看到评论所属的用户和帖子属于用户。

然而，当我尝试通过修补程序创建新帖子时（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;

这告诉我帖子必须有用户和评论的关系必须有一个用户也不能正常工作！知道如何解决这个问题吗？

迁移：

create_posts_migration：

<?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');
    }
}

create_comment_migration：

<?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');
    }
}

Answer 1

在迁移中添加外键约束，以在创建帖子时检查有效用户，并在创建评论时检查有效用户和帖子。这应该可以解决您的问题。

Saxon.Api.DynamicError

根据您的需要更改Schema::create('posts', function (Blueprint $table) { $table->increments('id'); $table->unsignedInteger('user_id'); $table->string('title'); $table->text('body'); $table->string('image'); $table->timestamps(); $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade'); }); Schema::create('comments', function (Blueprint $table) { $table->increments('id'); $table->unsignedInteger('post_id'); $table->unsignedInteger('user_id'); $table->string('email'); $table->string('name'); $table->string('body'); $table->timestamps(); $table->foreign('post_id')->references('id')->on('posts')->onDelete('cascade'); $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade'); });选项。删除父项时，onDelete将删除子关系。

Laravel属于关系不起作用

1 个答案: