How to get foreign key from eloquent collection in laravel

All we need is an easy explanation of the problem, so here it is.

I have hasMany relationship in my User model;

 * Get the posts for the users.
public function posts()
    return $this->hasMany(Posts::class); //foreign key assigned by user_id

I need to get a foreign id in Eloquent data


use App\Models\User;

$posts = User::find(1)->posts;

foreach ($posts as $post) {
//for example
$foreign_key = $posts->foreign_key;
echo "all posts collection assigned foreign key is; ".$foreign_key;

Expected output;


How can I get the foreign key?

How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

Method 1

You can do the following. Since posts has hasmany relation so it return collection of object even though you have one item in posts.

foreach ($posts as $post) {
    echo $post->user_id;



If you still need one item from posts relationship then you can add one relationship

public function post()
    return $this->hasOne(Posts::class); //foreign key assigned by user_id

then you can access

$posts = User::find(1)->post;

$foreign_key =$posts->user_id;

Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂

All methods was sourced from or, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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