Are you ure you want to group by user_id? What are you trying to do?

@kokokurak This is sample like sudo code.

But I think group by is not a problem.

if I use

$article = new Article();
        $query = $article->with('user')
            ->where('user_id', '=', 1)
        $user = $query->get(['name','post','user.name']);

select name, post from `articles` where `user_id` = ?
select name from `users` where `user`.`id` in (?)

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'user.name' in 'field list' (SQL: select `name`, `post`, `user`.`name` from `articles` where `user_id` = 1)

same error.

Can not try myself, byt try this:

$article = Article::with(array('user' => function($query)
{
    $query->select('id','name as username');
}
))->where('user_id', '=', 1)
   ->get(['name', 'post']);