Laravel and Redmine Database // query builder with eloquent

Question

I'm new in Laravel (5.4). I work on redmine database and I want to have users role. The tables are :

users : id, login, hashed_password,...
members : id, user_id, project_id, created_on, mail_notification
member_roles : id, member_id (foreign key), role_id, inherited_from
roles : id, name,...

My query works perfectly but I want to make it fluent without "->select(...)" :

$membersRole = DB::connection('redmine')
      ->select('SELECT roles.name  as role, user_id
        FROM users, members, projects, member_roles, roles
        WHERE projects.id = ?
                  AND members.user_id = ?
                  AND members.project_id = projects.id
                  AND members.id = member_roles.member_id
                  AND roles.id = member_roles.role_id
        LIMIT 1', [$id, $userId]);

How can I do it ?