// Entity Framework Extensions

​

// @nuget: EntityFramework

// @nuget: Z.EntityFramework.Extensions

​

using System;

using System.Collections.Generic;

using System.Linq;

using System.Data.Entity;

​

public class Program

{

    public static void Main()

    {

        // SEED

        using (var context = new EntityContext())

        {

            context.CsvRows.Add(new CsvRow() { IsActive = true, Flag = true, ActiveDate = null});       

            context.CsvRows.Add(new CsvRow() { IsActive = false, Flag = true, ActiveDate = DateTime.Now.AddDays(-7)});

            context.CsvRows.Add(new CsvRow() { IsActive = true, Flag = true, ActiveDate = DateTime.Now.AddDays(-7)});       

​

            context.SaveChanges();

            FiddleHelper.WriteTable("1 - Data Before", context.CsvRows.ToList());

        }

        // CSV Import

        using (var context = new EntityContext())

        {

            var list = new List<CsvRow>();

            list.Add(new CsvRow() { ID = 1, IsActive = true, Flag = true});

            list.Add(new CsvRow() { ID = 2, IsActive = true, Flag = true});

            list.Add(new CsvRow() { ID = 3, IsActive = false, Flag = true});

            // If any row has flag == true, I stamp the current date in the entity that I create.

            list.Where(x => x.Flag).ToList().ForEach(x => x.ActiveDate = DateTime.Now);

            context.BulkMerge(list, options => {

                options.PostConfiguration = config => {

                    var activeDateColumn = config.ColumnMappings.Single(x => x.SourceName == "ActiveDate");

                    // Destination.ActiveDate = IIF( Staging.IsActive = 0, NULL, ISNULL ( Destination. ActiveDate, Staging.ActiveDate))

                    activeDateColumn.FormulaUpdate = "CASE WHEN StagingTable.IsActive = 0 THEN NULL ELSE ISNULL(DestinationTable.ActiveDate, StagingTable.ActiveDate) END";

                };

            });

            FiddleHelper.WriteTable("2 - Data After", context.CsvRows.ToList());

        }

    }

​

    public class EntityContext : DbContext

    {

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

        {

​

        }

        public DbSet<CsvRow> CsvRows { get; set; }

    }   

    public class CsvRow

    {

        public int ID { get; set; }

        public bool IsActive { get; set; }

        public bool Flag { get; set; }

        public DateTime? ActiveDate { get; set; }

    }

}