class User extends Eloquent
{
    /**
     * @return \Illuminate\Database\Eloquent\Relations\HasOne
     */
    public function profile()
    {
        if ($this->role == 'doctor') {
            return $this->hasOne('App\Doctor', 'user_id', 'id')
                ->withDefault();
        }
        
        if ($this->role == 'pacient') {
            return $this->hasOne('App\Pacient', 'user_id', 'id')
                ->withDefault();
        }
        
        return null;
    }
}