Updating customer details

Let's go ahead and add some code to allow for updating customer details by following these steps:

1. Update ICustomerService to add the operation shown in the following code:

   [OperationContract]
   void Update(Customer customer);

2. Update CustomerService to implement the new operation as shown in the following code:

   public void Update(Customer customer)
   {
       Data.Customer customerEntity
           = _northwindEntities
               .Customers.Single(
                   c => c.CustomerID == customer.CustomerID);
       customerEntity.CompanyName = customer.CompanyName;
       customerEntity.ContactName = customer.ContactName;
       customerEntity.Address = customer.Address;
       customerEntity.City = customer.City;
       customerEntity.Country = customer.Country;
       customerEntity.Region = customer.Region;
       customerEntity.PostalCode = customer.PostalCode;
       customerEntity.Phone = customer.Phone;
       _northwindEntities.SaveChanges();
   }

3. Build and then right-click on the CustomerService...