Nsryjdtyk

I am currently working on a project where I need to be able to rent a truck to a customer but also need to add the customer details if not existing. My problem is even though through the WPF form I input the exact same details of a customer, there would be a new set of data added thus creating a new Customer ID for one person. How would I be able to get the database disregard the existing customer details?

My data service code:

 public class DataService

{

    public static void rentTruck(TruckRental toRent, bool isNewCustomer)

    {

        using (var ctx = new DAD_TruckRental_RGMContext())

        {



            if (!isNewCustomer)

            {



                ctx.Entry(toRent.Customer).State = EntityState.Unchanged;//doesnt leave existing customer unchanged

            }

            ctx.Entry(toRent.Truck).State = EntityState.Modified;

            ctx.TruckRental.Add(toRent);

            ctx.SaveChanges();

        }

    }

My cs code:

private void Button_Click(object sender, RoutedEventArgs e)

    {



            TruckCustomer cust = new TruckCustomer();

            cust.Age = int.Parse(ageTextBox.Text);

            cust.LicenseNumber = licenseNumberTextBox.Text;

            cust.LicenseExpiryDate = licenseExpiryDateDatePicker.SelectedDate.Value.Date;





            TruckPerson per = new TruckPerson();

            per.Address = addressTextBox.Text;

            per.Telephone = telephoneTextBox.Text;

            per.Name = nameTextBox.Text;



            cust.Customer = per;





            int truckId = int.Parse(truckIdTextBox.Text);

            IndividualTruck truck = DataService.searchTruckByID(truckId);



            decimal priceTotal = decimal.Parse(totalPriceTextBox.Text);



            TruckRental toRent = new TruckRental();

            toRent.TotalPrice = priceTotal;

        toRent.RentDate = rentDateDatePicker.SelectedDate.Value.Date;



        toRent.ReturnDueDate = returnDueDateDatePicker.SelectedDate.Value.Date;

            toRent.Customer = cust;

            toRent.Truck = truck;

            truck.Status = "Rented";





            DataService.rentTruck(toRent, true);



            MessageBox.Show("Truck rented succesfully");





    }

Here is my suggestion

1- First check if customer details already exist in db using LicenseNumber
2- The first step will be either null or have details, so if null then add received customer details otherwise update

here is the code

public class DataService

{

    public static void rentTruck(TruckRental toRent, bool isNewCustomer, TruckCustomer tcustomer)

    {

        using (var ctx = new DAD_TruckRental_RGMContext())

        {

           var ob =  ctx.TruckCustomer.Where(c => c.LicenseNumber   == customer.LicenseNumber);

           if ( ob != null) //not exist 

            {



            //create new here 

            ctx.TruckCustomer.Add(tcustomer);

        }



        //exist then just update State

        ctx.ob.State = EntityState.Modified;

        ctx.AddOrUpdate(ob);

        ctx.TruckRental.Add(toRent);

        ctx.SaveChanges();

    }

}

I hope this can help you