public static void Insert()
 {
     try
     {
         using (var context = new EFTestModelOnetoOneFluent())
         {
             context.Customers.Add(new Customer
             {
                 CustomerID = 6,
                 FirstName  = "Elan ",
                 LastName   = "Pancahcharam"
             });
             //context.SaveChanges();
             context.CustomerDetails.Add(new CustomerDetails
             {
                 CustomerID = 6,
                 Email      = "*****@*****.**",
                 Address    = "Puthukottai"
             });
             context.SaveChanges();
         }
     }
     catch (Exception ex)
     {
         Console.WriteLine(ex.Message);
     }
 }
        static void Main(string[] args)
        {
            //Customer customer;
            using (var context = new EFTestModelOnetoOneFluent())
            {
                IEnumerable <Customer> customers = context.Customers.ToList() as IEnumerable <Customer>;
                Console.WriteLine("Customer Details   : ");
                foreach (var item in customers)
                {
                    Console.WriteLine("Customer Name: " + string.Join(" ", new object[]
                    {
                        item.FirstName, item.LastName
                    }) + "    Customer Contacts   :" + string.Join(" ", new object[]
                    {
                        item.CustomerDetails.Email, item.CustomerDetails.Address
                    }));
                }

                Insert();
                Console.ReadKey();
            }
        }