如何通过ID将2个模型的字段传递给资源？

Question

在这里寻找数据检索专家。我想返回带有图片网址字段的文章。文章模型包含“ file_id”，它是文件模型“ id”的外键。我有一个ArticleResource返回文章。最好的方法是使用id将文件表中的URL插入ArticleResource的url字段中？

ArticleResource：

public function toArray($request)
{

    return [

        'id' => $this->id,
        'title' => $this->title,
        'article_content' => $this->article_content,
        'article_image' => $this->url,
        'article_image_alt' => $this->article_image_alt

    ];
}

ArticleController：

public function index()
{


   //Get Articles

   $articles = Article::paginate(10);
   $files = File::paginate(10);



   // Return collection of articles as a resource
   return ArticleResource::collection($articles); 
}

商品型号：

class Article extends Model
{
 protected $fillable = array('created_at','updated_at','article_title', 
'article_content', 'file_id','user_id');

public function file()
{
    return $this->hasOne('App\File');
}

public function user()
{
    return $this->hasOne('App\User');
}

}

文件模型：

class File extends Model
{
 use SoftDeletes;

protected $fillable = [
  'title','url','image_alt','created_at','updated_at','deleted_at','user_id'
];

public function user()
{
  return $this->belongsTo(User::class);
}
public function article()
{
  return $this->belongsTo(Article::class);
}


}