// Entity Framework Extensions

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

​

// @nuget: Microsoft.EntityFrameworkCore.SqlServer

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

​

using System;

using System.Text;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq;

using Microsoft.Data.SqlClient;

using Microsoft.EntityFrameworkCore;

public class Program

{

    public static void Main()

    {

        using (var context = new EntityContext())

        {

            context.Database.EnsureCreated();

        }

        // Insert data

        using (var context = new EntityContext())

        {

            context.BulkInsert(Data());

            context.BulkInsert(OrderData());

            //FiddleHelper.WriteTable("1 - Before: ", context.Customers.ToList());

        }

        using (var context = new EntityContext())

        {

            StringBuilder sb = new StringBuilder();

            var joined = from o in context.Orders 

                         join c in context.Customers on o.SecondaryID equals c.SecondaryID 

                         select new Order { OrderID = o.OrderID, CustomerID = c.CustomerID };

            FiddleHelper.WriteTable("1 - Before (Customer): ", context.Customers.AsNoTracking().ToList());

            FiddleHelper.WriteTable("1 - Before (Order): ", context.Orders.AsNoTracking().ToList());            

            joined.UpdateFromQuery(x => new Order { CustomerID = x.CustomerID }, options => {

                options.Executing = command => {

                    sb.AppendLine(command.CommandText);

                };

            });

            FiddleHelper.WriteTable("2 - After (Order): ", context.Orders.AsNoTracking().ToList());

            Console.Write(sb.ToString());

        }

    }

    public static List<Customer> Data() 

    {

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

        bool isActive = false;

        for(int i = 0; i < 3; i++)

        {

            isActive = !isActive;

            list.Add(new Customer() { Name = "Customer_" + i, Counter = i, SecondaryID = i });

        }

        return list;

    }

    public static List<Order> OrderData()

    {

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

        for (int i = 0; i <3; i++){

            list.Add(new Order() { SecondaryID = i });

        }

        return list;

    }

​

    public class EntityContext : DbContext

    {

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)

        {

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

​

            base.OnConfiguring(optionsBuilder);

        }

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

        public DbSet<Order> Orders {get;set;}

    }

    public class Customer

    {

        public int CustomerID { get; set; }

        public string Name { get; set; }

        public int Counter { get; set; } 

        public int SecondaryID {get;set;}

    }

    public class Order

    {

        public int OrderID {get;set;}

        public int? CustomerID { get; set;}

        public int? SecondaryID {get;set;}

    }

}