// @nuget: EntityFramework

​

using System;

using System.Data.Entity;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        using (var context = new EntityContext())

        {

            context.Customers.Add(new Customer { Name = "John" });

            context.SaveChanges();

        }

    }

​

    public class EntityContext : DbContext

    {

        public EntityContext() : base(FiddleHelper.GetConnectionStringSqlServer())

        {

​

        }

        public DbSet<Customer> Customers { get; set; }

    }

    public class Customer

    {

        public string Name { get; set; }

        public List<Invoice> Invoices { get; set; }

    }

    public class Invoice

    {

        public int InvoiceID { get; set; }

        public DateTime InvoiceDate { get; set; }

        public int CustomerID { get; set; }

        public Customer Customer { get; set; }

    }

}