空数据从多对多关系回归5

Question

我有两个名为application和user的模型。

应用

id |名称

用户

id |名字

application_user

id | application_id | user_id |评论|评级|像

这是模型类

<?php

namespace App;

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

class Application extends ModelValidator
{
    //
    protected $table = "application";

    public function user()
    {
        return $this->belongsToMany('App\User','application_user','application_id','user_id')->withPivot(['rating','like','comment'])->withTimestamps();
    }

    public function getComment()
    {
        $comments = array();

        foreach ($this->user as $user) {
            $comments[] = $user->comment;
        }

        return compact($comments);
    }
}

<?php

namespace App;

use Illuminate\Auth\Authenticatable;
use Illuminate\Auth\Passwords\CanResetPassword;
use Illuminate\Contracts\Auth\Authenticatable as AuthenticatableContract;
use Illuminate\Contracts\Auth\CanResetPassword as CanResetPasswordContract;
use Illuminate\Database\Eloquent\Model;

class User extends ModelValidator implements AuthenticatableContract,CanResetPasswordContract
{
    use Authenticatable,CanResetPassword;

    protected $table = 'user';

    public function application()
    {
        return $this->belongsToMany('App\Application')->withPivot(['rating','like','comment'])->withTimestamps();
    }
}

但是当我运行下面的代码时，它会打印出空数组。

$apps = \App\Application::all();

        foreach ($apps as $app) {
            print_r($app->getComment());
        }

为什么它返回空数组？

提前致谢

Answer 1

只需改变你的关系

<?php

namespace App;

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

class Application extends ModelValidator
{
    //
    protected $table = "application";

    public function user()
    {
        return $this->hasMany('App\ApplicationUser','application_id','id')
               ->withPivot(['rating','like','comment'])->withTimestamps();
    }

}

<?php

namespace App;

use Illuminate\Auth\Authenticatable;
use Illuminate\Auth\Passwords\CanResetPassword;
use Illuminate\Contracts\Auth\Authenticatable as AuthenticatableContract;
use Illuminate\Contracts\Auth\CanResetPassword as CanResetPasswordContract;
use Illuminate\Database\Eloquent\Model;

class User extends ModelValidator implements AuthenticatableContract,CanResetPasswordContract
{
    use Authenticatable,CanResetPassword;

    protected $table = 'user';

    public function application()
    {
        return $this->belongsToMany('App\Application')->withPivot(['rating','like','comment'])->withTimestamps();
    }
}

像这样更改您的代码。

foreach ($apps as $app) {
    print_r($app->user);
}

现在你从application_user表中获取数据，你得到了空的结果，因为你试图在用户表中找到一个数据，所以你的结果是空的。