using System.Collections.Generic;
using System.Data.Entity;
using System.Threading.Tasks;
public static void Main()
public static async Task MainAsync()
var customers = GenerateCustomers(2);
using (var context = new EntityContext())
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" });
await context.BulkMergeAsync(customers);
FiddleHelper.WriteTable("2 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);
public class EntityContext : DbContext
public EntityContext() : base(FiddleHelper.GetConnectionStringSqlServer())
public DbSet<Customer> Customers { get; set; }
public int CustomerID { get; set; }
public string Code { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }