EF.Plus - Query IncludeOptimized (EF Core)

CSharp · Console

/Program.cs

// 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())
        {
            // LOAD orders and the first 10 active related entities.
            var list = context.Orders.IncludeOptimized(x => x.Items).ToList();
			
			foreach(var order in list)
			{
				Console.WriteLine("Order items in {0}: {1}", order.Name, order.Items.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();
        }
    }

	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 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; }
    }
}