// Entity Framework Plus

// Doc: https://entityframework-plus.net/query-include-optimized

​

// @nuget: Microsoft.EntityFrameworkCore.SqlServer

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

​

using System;

using System.Linq;

using Z.EntityFramework.Plus;

using Microsoft.EntityFrameworkCore;

using Microsoft.Data.SqlClient;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        using (var context = new EntityContext())

        {

            context.Database.EnsureCreated();

        }

        GenerateData();

        // Update: UPDATE all rows from the database using a LINQ Query without loading entities in the context.

        using (var context = new EntityContext())

        {

            QueryIncludeOptimizedManager.AllowIncludeSubPath  = true;

            QueryIncludeOptimizedManager.AllowQueryBatch=true;

            // LOAD orders and the first 10 active related entities.

            //working

            var list = context.Orders

                        .IncludeOptimized(x => x.Items.Select(o=>o.OrderItemDetails))

                        .IncludeOptimized(x => x.Items.SelectMany(o=>o.OrderItemDetails).Select(y=>y.Gifts)).ToList();

            //not working

             var list2 = context.Orders

                        .IncludeOptimized(x => x.Items.Select(o=>o.OrderItemDetails))

                        .IncludeOptimized(x => x.Items.Select(o=>o.OrderItemDetails.Select(y=>y.Gifts))).ToList();  

            foreach(var order in list)

            {

                Console.WriteLine("Order items in {0}: {1}", order.Name, order.Items.Count());

                foreach (var orderItem in order.Items)

                {

                    Console.WriteLine("Order item Id:{0} details count {1}",orderItem.OrderItemId,orderItem.OrderItemDetails.Count());

                    foreach (var orderItemDetail in orderItem.OrderItemDetails) 

                    {

                            Console.WriteLine("Order Item Detail Id: {0},Gifts count {1}",orderItemDetail.OrderItemDetailId,orderItemDetail.Gifts.Count());

                    }

                }

            }

        }

    }

    public static void GenerateData()

    {

​

        using (var context = new EntityContext())

        {

            context.Orders.Add(new Order() { Name = "Order_A", Date = DateTime.Now.AddDays(-4), IsSoftDeleted = true });

            context.Orders.Add(new Order() { Name = "Order_B", Date = DateTime.Now.AddDays(-5), IsSoftDeleted = true });

​

            context.SaveChanges();

​

            context.Items.Add(new OrderItem() { Date = DateTime.Now.AddDays(-4), IsSoftDeleted = false, Price = 35, OrderId = 1 });

            context.Items.Add(new OrderItem() { Date = DateTime.Now.AddDays(-4), IsSoftDeleted = false, Price = 22, OrderId = 1 });

            context.Items.Add(new OrderItem() { Date = DateTime.Now.AddDays(-5), IsSoftDeleted = false, Price = 37, OrderId = 2 });

            context.Items.Add(new OrderItem() { Date = DateTime.Now.AddDays(-5), IsSoftDeleted = true, Price = 7, OrderId = 2 });

​

            context.SaveChanges();

            context.OrderItemDetails.Add(new OrderItemDetail() {  OrderItemId = 1 });

            context.OrderItemDetails.Add(new OrderItemDetail() {  OrderItemId = 1 });

            context.OrderItemDetails.Add(new OrderItemDetail() {  OrderItemId = 2 });

            context.OrderItemDetails.Add(new OrderItemDetail() {OrderItemId = 2 });

            context.SaveChanges();

            context.Gifts.Add(new Gift() {  OrderItemDetailId = 1 });

            context.Gifts.Add(new Gift() {  OrderItemDetailId = 1 });

            context.Gifts.Add(new Gift() {  OrderItemDetailId = 2 });

            context.Gifts.Add(new Gift() {  OrderItemDetailId = 2 });

            context.SaveChanges();

        }

    }

​

    public class EntityContext : DbContext

    {

        public EntityContext() 

        {

        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)

        {

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

​

            base.OnConfiguring(optionsBuilder);

        }

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

        public DbSet<OrderItem> Items { get; set; }

        public DbSet<OrderItemDetail> OrderItemDetails { get; set; }

        public DbSet<Gift> Gifts { get; set; }

    }

​

    public class Order

    {

        public int OrderId { get; set; }

        public string Name { get; set; }

        public DateTime Date { get; set; }

        public bool IsSoftDeleted { get; set; }

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

    }

​

    public class OrderItem

    {

        public int OrderItemId { get; set; }

        public DateTime Date { get; set; }

        public bool IsSoftDeleted { get; set; }

        public int Price { get; set; }

        public int OrderId { get; set; }

        public List<OrderItemDetail> OrderItemDetails{get;set;}

    }

    public class OrderItemDetail

    {

        public int OrderItemDetailId {get;set;} 

​

        public int OrderItemId { get; set; }

        public List<Gift> Gifts{get;set;}

    }

    public class Gift

    {

        public int GiftId {get;set;}

        public int OrderItemDetailId { get; set; }

    }

}