// @nuget: EntityFramework

// @nuget: Z.EntityFramework.Extensions

​

using System;

using System.Linq;

using System.Data.Entity;

using System.Collections.Generic;

using Z.EntityFramework.Extensions;

using System.Data.Entity.Infrastructure;

​

public class Program

{

    public static void Main()

    {

        GenerateData();

        EntityFrameworkManager.PreBatchSaveChanges = ctx =>

        {

            var modifiedEntities = ctx.ChangeTracker.Entries().ToList();

​

            foreach (var change in modifiedEntities)

            {

                var objectStateEntry = ((IObjectContextAdapter)ctx).ObjectContext.ObjectStateManager.GetObjectStateEntry(change.Entity);

​

                if (objectStateEntry.State == EntityState.Added)

                {

                    change.CurrentValues["CreatedDate"] = DateTime.Now;

                }

                else if (objectStateEntry.State == EntityState.Modified)

                {

                    change.CurrentValues["ModifiedDate"] = DateTime.Now;

                }

            }

        };

​

        using (var context = new EntityContext())

        {

            var list = context.Customers.ToList();

            context.Customers.RemoveRange(list.Take(2));

            list.ForEach(x => { x.Name += "_Updated"; x.IsActive = false; });

            var newCustomers = new List<Customer>();

            newCustomers.Add(new Customer() { Name ="Customer_E", IsActive = true});

            newCustomers.Add(new Customer() { Name ="Customer_F", IsActive = true});

            context.Customers.AddRange(newCustomers);

            context.BatchSaveChanges();

        }

        using (var context = new EntityContext())

        {

            FiddleHelper.WriteTable("After_BulkMerge", context.Customers.ToList());

        }

    }

    public static void GenerateData()

    {   

        using (var context = new EntityContext())

        {

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

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

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

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

​

            context.BulkSaveChanges();  

        }

        using (var context = new EntityContext())

        {

            FiddleHelper.WriteTable("Before_BulkMerge", context.Customers.ToList());    

        }

    }

​

    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; }

        public DateTime? CreatedDate { get; set; }

        public DateTime? ModifiedDate { get; set; }

    }

}