public List <TourCustomerDTO> GetTourCustomerByCustomerId(string userId) { var tourCustomer = _dataBase.TourCustomers.GetAll(); var customerId = _dataBase.Customers.GetCustomerIdByIdentityUserId(userId); var customerTour = tourCustomer.Where(u => u.CustomerId == customerId); if (customerTour is null) { throw new ValidationException("Failed to get manager", "null error"); } var tourDto = MappingDTO.MapTourCustomerListDTO(customerTour.ToList()); return(tourDto); }