// Entity Framework Extensions

// Doc: https://entityframework-extensions.net/insert-keep-identity

​

// @nuget: Microsoft.EntityFrameworkCore.SqlServer

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

​

using System.Linq;

using Microsoft.EntityFrameworkCore;

using System.Collections.Generic;

using Microsoft.Data.SqlClient;

using Z.BulkOperations;

​

public class Program

{

    public static void Main()

    {

        using (var context = new EntityContext())

        {

            context.Database.EnsureCreated();

        }

        GenerateData();

        List<Invoice> invoices;

        using (var context = new EntityContext())

        {

            invoices = context.Invoices.Include(x => x.InvoiceItems).ToList();

        }

        invoices.ForEach(x => {x.Description = x.Description.Replace("Invoice", "Updated"); x.InvoiceItems.ForEach(y => y.Description = y.Description.Replace("Invoice", "Updated"));});

        // ReadOnly: You can specify that some entities should not be inserted/updated by marked marking them as ReadOnly. 

        using (var context = new EntityContext())

        {

            context.BulkMerge(invoices, options => {

                        options.IncludeGraph = true;

                        options.IncludeGraphOperationBuilder = operation =>

                        {

                            if (operation is BulkOperation<InvoiceItem>)

                            {

                                var bulk = (BulkOperation<InvoiceItem>) operation;

                                bulk.IsReadOnly = true;

                            }

                        };

                    });

        }

        using (var context = new EntityContext())

        {

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

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

        }

    }

​

    public static void GenerateData()

    {

        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" }}}};

        // BulkInsert: INCLUDE child entities

        using (var context = new EntityContext())

        {

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

        }

    }

    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; }

    }

}