// Entity Framework Classic

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

​

// @nuget: Z.EntityFramework.Classic

// @nuget: Z.EntityFramework.Plus.QueryIncludeOptimized.EFClassic

​

using System;

using System.Collections.Generic;

using System.Data.Entity;

using System.Linq;

using Z.Expressions;

using Z.EntityFramework.Plus;

public class Program

{

    public static void Main()

    {

        GenerateData();

        using (var context = new EntityContext())

        {

            var query = context.Customers.IncludeOptimized(x => x.Invoices.Where(y => !y.IsSoftDeleted))

                .IncludeOptimized(x => x.Invoices.Where(y => !y.IsSoftDeleted)

                               .Select(y => y.InvoiceItems.Where(z => !z.IsSoftDeleted)));

            FiddleHelper.WriteTable("InvoiceItems", query.ToList().SelectMany( x => x.Invoices.SelectMany(z => z.InvoiceItems)));

        }       

    }

    public static void GenerateData()

    {

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

                        new Customer() { Invoices = new List<Invoice>() {

                            new Invoice() { Description = "Invoice_A", IsSoftDeleted = false , InvoiceItems = new List<InvoiceItem>() { new InvoiceItem() { Description = "Invoice_A_InvoiceItem_A", IsSoftDeleted = false  } ,

                                                                                                   new InvoiceItem() { Description = "Invoice_A_InvoiceItem_B", IsSoftDeleted = true  }}},

                            new Invoice() { Description = "Invoice_B", IsSoftDeleted = true , InvoiceItems = new List<InvoiceItem>() { new InvoiceItem() { Description = "Invoice_B_InvoiceItem_A", IsSoftDeleted = false } ,

                                                                                                   new InvoiceItem() { Description = "Invoice_B_InvoiceItem_B", IsSoftDeleted = true  }}}}

                        }

                    };

        // BulkInsert: INCLUDE child entities

        using (var context = new EntityContext())

        {

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

        }

    }

​

    public class EntityContext : DbContext

    {

        public EntityContext() : base(FiddleHelper.GetConnectionStringSqlServer())

        {

​

        }

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

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

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

    }

    public class Customer

    {

        public int CustomerID { get; set; }

        public string Name { get; set; }

        public string Description { get; set; }

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

    }

    public class Invoice

    {

        public int InvoiceID { get; set; }

        public string Description { get; set; }

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

        public bool IsSoftDeleted { get; set; }

    }

    public class InvoiceItem

    {

        public int InvoiceItemID { get; set; }

        public string Description { get; set; }

        public bool IsSoftDeleted { get; set; }

    }

}