// Entity Framework Extensions

// Doc: https://entityframework-extensions.net/include-graph

​

// @nuget: Microsoft.EntityFrameworkCore.SqlServer

// @nuget: Z.EntityFramework.Extensions.EFCore

​

using System;

using System.Linq;

using Microsoft.EntityFrameworkCore;

using System.Collections.Generic;

using Microsoft.Data.SqlClient;

using System.ComponentModel.DataAnnotations;

using System.ComponentModel.DataAnnotations.Schema;

​

public class Program

{

    public static void Main()

    {

        using (var context = new EntityContext())

        {

            context.Database.EnsureCreated();

        }

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

        {

            new Invoice() 

            { 

                Description = "Invoice_A", 

                InvoiceItems = new List<InvoiceItem>() 

                { 

                    new InvoiceItem() { Description = "Invoice_A_InvoiceItem_A" } , 

                    new InvoiceItem() { Description = "Invoice_A_InvoiceItem_B" }

                }

            }, 

            new Invoice() 

            { 

                Description = "Invoice_B", 

                InvoiceItems = new List<InvoiceItem>() 

                { 

                    new InvoiceItem() { Description = "Invoice_B_InvoiceItem_A" } ,

                    new InvoiceItem() { Description = "Invoice_B_InvoiceItem_B" }

                }

            }

        };

        // IncludeGraph: The IncludeGraph option allows to INSERT/UPDATE/MERGE entities by including the child entities graph.

        using (var context = new EntityContext())

        {

            context.BulkInsert(list, options => options.IncludeGraph = true);

        }

        using (var context = new EntityContext())

        {

            FiddleHelper.WriteTable(context.Invoices.ToList().Select(x => new { x.InvoiceID, x.Description}));

            FiddleHelper.WriteTable(context.InvoiceItems.ToList());

        }

    }

​

    public class EntityContext : DbContext

    {

        public EntityContext() 

        {

        }

​

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)

        {

            optionsBuilder.UseSqlServer(new SqlConnection(FiddleHelper.GetConnectionStringSqlServer()));

​

            base.OnConfiguring(optionsBuilder);

        }

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

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

    }

    public class Invoice

    {

        public int InvoiceID { get; set; }

        public string Description { get; set; }

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

    }

    public class InvoiceItem

    {

        public int InvoiceItemID { get; set; }

        public string Description { get; set; }

    }

}