// Entity Framework Extensions

// Doc: https://entityframework-extensions.net/ignore-on-merge-insert-expression

​

// @nuget: Microsoft.EntityFrameworkCore.SqlServer

// @nuget: Z.EntityFramework.Extensions.EFCore

​

using System;

using System.Linq;

using Microsoft.EntityFrameworkCore;

using System.Collections.Generic;

using Microsoft.Data.SqlClient;

using Z.BulkOperations;

​

public class Program

{

    public static void Main()

    {

        using (var context = new EntityContext())

        {

            context.Database.EnsureCreated();

        }

        // IgnoreOnMergeInsertExpression: Gets or sets columns to ignore when the `BulkMerge` method executes the `insert` statement.

        using (var context = new EntityContext())

        {

            var list = context.Customers.ToList();

            list.Add(new Customer() { CustomerID =555, Name ="Customer_C", Description = "NOT_HERE", IsActive = false});

            context.BulkMerge(list, options => 

            {

                options.IgnoreOnMergeInsertExpression = customer => new {customer.CustomerID,  customer.Description};

            });

        }

        using (var context = new EntityContext())

        {

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

        }

    }

​

    public class EntityContext : DbContext

    {

        public EntityContext() 

        {

        }

​

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)

        {

            optionsBuilder.UseSqlServer(new SqlConnection(FiddleHelper.GetConnectionStringSqlServer()));

​

            base.OnConfiguring(optionsBuilder);

        }

        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; }

    }

}