// Entity Framework Extensions

// Doc: https://entityframework-extensions.net/bulk-insert

​

// @nuget: Z.EntityFramework.Extensions

// @nuget: EntityFramework

​

using System;

using System.Data.Entity;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var invoices = GenerateInvoices(5, 3);

        var items = invoices.SelectMany(x => x.Items);

        using (var context = new EntityContext())

        {

            context.BulkInsert(invoices);

            try

            {

                context.BulkInsert(items);

            }

            catch

            {

                Console.WriteLine("An error is throw because the Invoice relation cannot be found.");

            }

            context.Invoices.AddRange(invoices);

            // The ChangeTracker is used for this case

            context.BulkInsert(items);

            FiddleHelper.WriteTable("2 - Invoices", context.Invoices);

            FiddleHelper.WriteTable("3 - InvoiceItems", context.InvoiceItems);

        }   

    }

​

    public static List<Invoice> GenerateInvoices(int countInvoice, int countInvoiceItem) 

    {

        List<Invoice>  list = new List<Invoice>();

        for(int i = 0; i < countInvoice; i++)

        {

            var invoice = new Invoice() { Number = "Number_" + i, Items = new List<InvoiceItem>() };

            list.Add(invoice);

            for(int j = 0; j < countInvoiceItem; j++)

            {

                invoice.Items.Add(new InvoiceItem() { ProductName = "ProductName_" + i + "_" + j });

            }

        }

        return list;

    }

​

    public class EntityContext : DbContext

    {

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

        {

​

        }

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

        public DbSet<InvoiceItem> InvoiceItems { get; set; }

    }

​

    public class Invoice

    {

        public int InvoiceID { get; set; }

        public string Number { get; set; }

        public List<InvoiceItem> Items { get; set; }

    }

    public class InvoiceItem

    {

        public int InvoiceItemID { get; set; }

        public string ProductName { get; set; }

    }

}