I would like to know what is the best practice in this case:
Customer`s firstname + lastname has a unique index so if I do insert the same name again I get a constraint exception (update exception). in my Repository. What is no the best way to show a user a message box saying update failed because customer already exists?
Do the InserCustomer with a return code like
In my presenter/viewmodel
int updateStatus = repository.CreateCustomer()
if(updateStatus == -1)