无法将新闻项目附加到数据透视表中的用户

Question

这是a previous post的后续帖子

我正在尝试通过数据透视表将新闻项目附加到用户，以便我可以在每个用户登录后向他们显示新闻项目。这个想法是当用户看到一个项目时，他们可以选中一个框以分离该项目，而不再看到它。

我的新闻项目似乎正在保存，但数据透视表中没有保存任何内容以将它们与用户关联。理想情况下，当一条新闻被保存时，它应该附加到所有用户。

迁移

create_news_table

class CreateNewsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('news', function (Blueprint $table) {
            $table->increments('id');
            $table->string('title');
            $table->string('body');
            $table->boolean('sticky');
            $table->boolean('draft');
            $table->timestamps();
        });
    }

create_news_user_pivot_table

class CreateNewsUserPivotTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('news_user', function (Blueprint $table) {
            $table->integer('user_id')->unsigned();
            $table->integer('news_id')->unsigned();
            $table->foreign('user_id')->references('id')->on('users')
                ->onDelete('cascade');
            $table->foreign('news_id')->references('id')->on('news')
                ->onDelete('cascade');
            $table->timestamps();
        });
    }

模型

News.php

namespace App;

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

class News extends Model
{
    protected $table = 'news';
    protected $fillable = ['title', 'body', 'sticky', 'draft',];

    public function users() 
    {
        return $this->belongsToMany('App\News')->withPivot('user_id', 'news_id');
    }
}

User.php

class User extends Authenticatable {

        use Notifiable;
        use SoftDeletes;


        //protected $table = "users";
        /**
         * The attributes that are mass assignable.
         *
         * @var array
         */
        protected $fillable = [
            'name',
            'email',
            'password',
            'profilePic',
            'role',
            'verify',
            'first_time_login',
            'changedPasswordDate',
            'needToChangePassword',
            'userRoles'
        ];

        protected $dates = ['deleted_at'];

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

        public function news() {
            return $this->belongsToMany('App\News')->withPivot('user_id', 'news_id');
        }
}

NewsUser.php（甚至不确定我需要数据透视表的模型）

namespace App;

use Illuminate\Database\Eloquent\Model;

class NewsUser extends Model {

    protected $table = 'news_user';
    protected $fillable = ["user_id", "news_id"];
}

控制器的相关功能

public function saveNews(Request $request) {
        $user = Auth::user();

        $news = new News;
        $news->title = $request->title;
        $news->body = $request->body;
        $news->sticky = $request->sticky;
        $news->draft = $request->draft;
        $news->save();
        $user->news()->attach($news->id);
    }

我意识到这最后一个函数只是试图将新闻帖子添加到当前用户，但如果我解决了这个问题，那么我以后可以弄清楚如何将新闻项目附加到所有用户。我猜是这样的：

$users = \App\User::all()

foreach $users as $user {
    $user->news()->attach($news->id);
}

Answer 1

我在这里猜测return $this->belongsToMany('App\News')->withPivot('user_id', 'news_id');

也许在用户模型中尝试return $this->belongsToMany('App\News', 'news_user', 'user_id', 'news_id');，在新闻模型中反之亦然，因为belongsToMany() 将出现外键，withPivot() 添加了额外的属性，但您使用它的外键，因为它是额外的属性

Answer 2

我在一个地方查看所有代码时发现了几个问题。

News.php

public function users()

应该是

public function user()

它也返回错误，'App\News' 应该是 'App\User'

return $this->belongsToMany('App\News')->withPivot('user_id', 'news_id');

应该是

return $this->belongsToMany('App\User', 'news_user', 'news_id');

然后在我的控制器中，在保存后将新闻项附加到所有用户

foreach ($users as $user) {
    $news->user()->attach($user->id);
}