与同一表Laravel 5具有相同外键的关系

Question

I am building a referral system, the table User is referred by another, for example:

User table:

id

name

Referrals table:

id

referred_by (user_id)

refers_to (user_id)

Same foreign key to the same table. Which are the relationships between User table and Referrals?

Answer 1

I am assuming your user model is App\User and your Referral model is App\Referral:

If you want to get, via your user, who they have referred you can do in App\User:

function  referredBy() {
    return $this->hasMany('App\Referral', 'referred_by');
}

If you want to get, via your user, who they were referred by:

function referredTo() {
    return $this->hasMany('App\Referral', 'refers_to');
}   

Anywhere you have a $user object, you can get a list of all other referenced users by $user->referredTo() or $user->referredBy() The Eloquent models allow you to create many different style relations with different key names.

Reference: https://laravel.com/docs/5.5/eloquent-relationships#introduction