Trying to get data via related table in Laravel - php

Question

What I'm trying to do is to show the posts that have been saved by the user in the profile. I will try to explain it as good as possible refering to my code. So:
public function userProfil($id)
I have the profile function which get the data from userprofile table. and inside I have the following code for saved data:
$authed = User::find($id);
$savedarticles = $authed->mysaves;
$allsavings = DB::select("Select * from article where id=$savedarticles->id");
But this code does not work like this anyway. I can do this instead:
$authed = User::find($id);
$savedarticles = $authed->mysaves;
But when I try to get articles from article table with the article_id of mysaves, it does not work such as this:
$allsaved= DB::table('article')->where('id', $savedarticles->article_id);
the error it gives is like:
Property [article_id] does not exist on this collection instance.
although savearticle table has article_id I can output it without the line above and in view I get them as:
#foreach($savedarticles as $savedarticle)
<p>{{$savedarticle}}</p>
#endforeach
it gives me everything that is in the savearticle table and I can get do savedarticle->article_id and get article_id but can't get it in controller.
I am using Laravel 5.4.

Answer 1

The error message Property [article_id] does not exist on this collection instance. means you are trying to get an attribute of a single instance but from a collection.
For example the collection could be like
[$article1, $article2, $article3]
therefore what you tried to do is something similar to
[$article1, $article2, $article3]->article_id
You are trying to get an attribute from a collection instead of a single instance.
As for your query, you can use where in sql statement to search for rows that match any item in an array
$allsaved= DB::table('article')->whereIn('id', $savedarticles->pluck('article_id')->all());

Answer 2

What I have understood is that A USER has many POSTS and a POST belong to an article.
If this is true then you have to do following.
1: In USER model define a relation to get all posts. like below.
public function posts() {
// Foreign key will be a key that is stored in posts table and represent the user MAY BE: user_id
$this->hasMany(Posts::class, 'foreign_key', 'local_key')
}
This will allow you to get all posts belong to a user.
2: In posts, model defines a user relation like below.
public function user() {
$this->belongsTo(User::class, 'foreign_key', 'local_key');
}
This will allow you to get a post User;
3: Now in your controller you will have something like this.
public function show($user_id) {
// find a user with posts as eager loading(to avoid query again)
$user = User::with(['posts'])->where('id', $user_id)->first();
// get all posts that belong to this user
$posts = $user->posts;
}
In controller show($user_id) method you will have a user data as well as user posts data. Now if you want to get a post relations then simply define as below. let say a post belongs to an article as well.
4: In posts, model defines a relation to get an article.
public function article() {
// This will allow you to get a post artcle
$this->belongsTo(Article::class, 'foreign_key', 'local_key');
}
Now you can get the article as well while finding a user. please see below. I am rewriting controller show action to give you a better understanding.
5: Get a user with user_id
public function show($user_id) {
// find a user with posts as eager loading(to avoid query again)
// eager loading for posts & post child, this will give you NOSQL at runtime and all data will come from one query.
$user = User::with(['posts', 'posts.article'])->where('id', $user_id)->first();
// get all posts that belong to this user
$posts = $user->posts;
foreach($posts as $post) {
$article = $post->article; // Child relation of post.
}
}
Hope you will understand the flow, you have to make sure models relation to work it perfectly. If you need further help please let me know.