// Entity Framework Classic

// Doc: https://entityframework-classic.net/bulk-save-changes

​

// @nuget: Z.EntityFramework.Classic

​

using System;

using System.Collections.Generic;

using System.Linq;

using System.Data.Entity;

using System.Threading.Tasks;

public class Program

{   

    public static void Main()

    {

        MainAsync().Wait();

    }

    public static async Task MainAsync()

    {

        GenerateData();

​

        // BulkSaveChanges: BulkSaveChanges works exactly like `SaveChanges` but faster.

        using (var context = new EntityContext())

        {

            var listToRemove = context.Customers.Where(x => x.IsActive == false ).ToList();

            var listToModify = context.Customers.Where(x => x.IsActive == true ).ToList();

            var listToAdd = new List<Customer>() { new Customer() { Name = "Customer_C", Description = "Description", IsActive = false}};

            context.Customers.AddRange(listToAdd); // add

            context.Customers.RemoveRange(listToRemove); // remove

            listToModify.First().Description = "Updated_A"; // modify

            await context.BulkSaveChangesAsync(false);

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

        }

        // BulkSaveChanges: Easy to customize

        using (var context = new EntityContext())

        {

            context.Customers.AddRange(GenerateListCustomer());

            context.BulkSaveChanges(bulk => bulk.BatchSize = 100);

            FiddleHelper.WriteTable(context.Customers.Take(5).ToList());

        }

    }

    public static void GenerateData()

    {

        using (var context = new EntityContext())

        {

            context.Customers.Add(new Customer() { Name ="Customer_A", Description = "Description", IsActive = true });

            context.Customers.Add(new Customer() { Name ="Customer_B", Description = "Description", IsActive = false });

            context.BulkSaveChanges();  

        }

        using (var context = new EntityContext())

        {

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

        }

    }

    public static List<Customer> GenerateListCustomer() 

    {

        var customers = new List<Customer>();

        for (int i = 0; i < 1000; i++)

        {

            customers.Add(new Customer() { Name ="Customer_" + i, Description = "Description", IsActive = true });

        }

        return customers;

    }

​

    public class EntityContext : DbContext

    {

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

        {

​

        }

        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 Boolean IsActive { get; set; }

    }

}