如何通过中间表从一个模型到另一个模型使用雄辩

Question

i have three models

Article

id 
title 

Comment

id
title
user_id
article_id

User

id 
name

what i wanna achieve is to select one article based on its id with comments and user info that made that comment

like that :

$article = Article::find($id -- say 1)->with('comments' -- this is a relation in Article Model)->get(); 

this gives me article with related comments as an array of objects say comment one - comment two etc ....

what i want instead of user_id in comment object i wanna it to be a user object

see this pic thats what i reached so far

using laravel 5.4

Answer 1

You can use following:

$articles = Article::find($id)->with('comments', 'comments.user')->get();

Here 'user' is the relationship you mentioned in the comments model for User.

Answer 2

If you have defined the foreign key relationship in Schemas, you can define functions for Eloquent Relationship as defined in following reference link - Laravel - Eloquent Relationships .

You can define functions in models as follows -

Article -

  class Article extends Model
  {
     ...

     public function comments(){

         // Accessing comments posted to that article.

         return $this->hasMany(\App\Comment::class);
     }

     // Create a foreign key to refer the user who created the article. I've referred it here as 'created_by'. That would keep relationship circle complete. You may ignore it if you want.

     public define user(){

         // Accessing user who posted the article

         return $this->hasOne(\App\User::class, 'id', 'created_by');
     }
  }

Comment -

  class Comment extends Model
  {
     ...

     public function article(){

         // Accessing article to which the particular comment was posted

         return $this->hasOne(\App\Article::class, 'id', 'article_id');
     }

     public function user(){

         // Accessing user who posted the comment

         return $this->hasOne(\App\User::class, 'id', 'user_id');
     }
  }

User -

  class User extends Models
  {
     ...

     public function articles(){

         // Accessing articles posted by a user

         return $this->hasMany(\App\Article::class);
     }

     public function comments(){

         // Accessing comments posted by a user

         return $this->hasMany(\App\Comment::class);
     }
  }

Now you can use like following -

   $article = Article::findOrFail($id);
   $comments = $article->comments;
   $article_user = $article->user;
   $comment_user = Comment::findOrFail($commnet_id)->user;
   $users_comments = User::findOrFail($user_id)->comments;
   $users_articles = User::findOrFail($user_id)->articles;

and so on...

Answer 3

It is far better to use ->find() at last instead of ->get() because get() returns a Collection.

This way you will get a single object which you want instead of a Collection.

For example:

$commentableObj = Post::with(['comments'])
                  ->withCount(['comments'])
                  ->findOrFail($commentable->id);