Laravel leftJoin AS - php

Question

How can I make that query in Laravel Eloquent or Fluent?
DUELS
|id|userId1 | UserId2
-------------------------
|1| 1 | 4 |
|2| 3 | 2 |
|3| 2 | 1 |
-------------------------
USERS
|id| firstName |
----------------
|1| Bob |
|2| Hans |
|3| Jerome |
|3| Katy |
----------------
Query: get the names of the users in the duels where the user with $userId is participating:
SELECT u1.firstName AS user1FirstName, u2.firstName AS user2FirstName
FROM duels
LEFT JOIN users AS u1
ON userId1 = u1.id
LEFT JOIN users AS u2
ON userId2 = u2.id
WHERE userId1 = $userId || userId2 = $userId

Answer 1

Using Laravel's Fluent, to perform that query you need to do the following:
DB::table('users')->join('duels', function($join) use ($userId){
$join->on('users.id', '=', 'duels.userId1')
->orOn('users.id', '=', 'duels.userId2')
->where('users.id', '=', $userId);
})->get();
Using Laravel's Eloquent, however, you may consider the user as either first player, or as second player.
In your User model, define the above two relationships as such:
class User extends Eloquent{
/**
* ...
*/
public function duelsAsFirstPlayer(){
return $this->belongsToMany( 'App\User', 'duels', 'user_id_1', 'user_id_2');
}
public function duelsAsSecondPlayer(){
return $this->belongsToMany( 'App\User', 'duels', 'user_id_2', 'user_id_1');
}
}
Now, in order to get all the users the user with $userId has duels with, query the User model as such:
as first player:
$users = App\User::find($userId)->duelsAsFirstPlayer()->get();
or as second player:
$users = App\User::find($userId)->duelsAsSecondPlayer()->get();