code: func selectRegistration(s dbOneSelector, q string, args ...interface{}) (*regModel, error) {
  	var model regModel
  	err := s.SelectOne(
  		&model,
  		"SELECT "+regFields+" FROM registrations "+q,
  		args...,
  	)
  	return &model, err
  }
docs: // selectRegistration selects all fields of one registration model