// Entity Framework Classic

// Doc: https://entityframework-classic.net/bulk-merge

​

// @nuget: Z.EntityFramework.Classic

​

using System;

using System.Collections.Generic;

using System.Linq;

using System.Data.Entity;

public class Program

{

    public static void Main()

    {

        var customers = GenerateCustomers(2);

​

        using (var context = new EntityContext())

        {

            // Easy to use

            customers.ForEach(x => x.FirstName += "_Updated");

            customers.Add(new Customer() { Code = "CodeNew_1", FirstName = "FirstNameNew_1", LastName = "LastNameNew_1" });

            customers.Add(new Customer() { Code = "CodeNew_2", FirstName = "FirstNameNew_2", LastName = "LastNameNew_2" });

            context.BulkMerge(customers);

            FiddleHelper.WriteTable("2 entities updated, 2 entities added", context.Customers.ToList());    

        }

        using(var context = new EntityContext())

        {

            // Easy to customize

            customers.ForEach(x => x.LastName += "_Updated");

            customers.Add(new Customer() { Code = "CodeNew_3", FirstName = "FirstNameNew_3", LastName = "LastNameNew_3" });

            customers.Add(new Customer() { Code = "CodeNew_4", FirstName = "FirstNameNew_4", LastName = "LastNameNew_4" });

            context.BulkMerge(customers, options => options.ColumnPrimaryKeyExpression = customer => customer.Code);

            FiddleHelper.WriteTable("4 entities updated, 2 entities added", context.Customers.ToList());    

        }

    }

    public static List<Customer> GenerateCustomers(int count)

    {

        var list = new List<Customer>();

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

        {

            list.Add(new Customer() { Code = "Code_" + i, FirstName = "FirstName_" + i, LastName = "LastName_" + i });

        }

        using (var context = new EntityContext())

        {

            context.BulkInsert(list);

        }

        return list;

    }

​

    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 Code { get; set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

    }

}