// Entity Framework Extensions

// Doc: https://entityframework-extensions.net/context-factory

​

// @nuget: EntityFramework

// @nuget: Z.EntityFramework.Extensions

​

using System.Data.Entity;

using System.Collections.Generic;

using System.Linq;

using Z.EntityFramework.Extensions;

public class Program

{

    public static void Main()

    {

        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" }}}};

        // ContextFactory: The context factory is a function `Func<DbContext, DbContext>` that provide the current DbContext as a parameter and requires to return a new DbContext.

        EntityFrameworkManager.ContextFactory = context => new EntityContextChild();

        using (var context = new EntityContext(FiddleHelper.GetConnectionStringSqlServer()))

        {

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

        }

        using (var context = new EntityContext(FiddleHelper.GetConnectionStringSqlServer()))

        {

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

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

        }

    }

​

    public class EntityContext : DbContext

    {

        public EntityContext(string connection) : base(connection)

        {

​

        }

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

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

    }

    public class EntityContextChild : EntityContext

    {

        public static string connection = FiddleHelper.GetConnectionStringSqlServer();

        public EntityContextChild() : base(connection)

        {

        }

    }

    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; }

    }

}