// Entity Framework Extensions

// Doc: https://entityframework-extensions.net/ignore-on-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();

        }

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

        using (var context = new EntityContext())

        {

            var customers = new List<Customer>();

            customers.Add(new Customer() { Name = "Alexander", Description = "Description of Alexander", CreatedDate = DateTime.Now, ModifiedDate = DateTime.Now, IsActive = true });

            customers.Add(new Customer() { Name = "Carson", Description = "Description of Carson", CreatedDate = DateTime.Now, ModifiedDate = DateTime.Now, IsActive = true });

            customers.Add(new Customer() { Name = "Meredith", Description = "Description of Meredith", CreatedDate = DateTime.Now, ModifiedDate = DateTime.Now, IsActive = true });

            customers.Add(new Customer() { Name = "Arturo", Description = "Description of Arturo", CreatedDate = DateTime.Now, ModifiedDate = DateTime.Now, IsActive = true });

            context.BulkInsert(customers, options => 

            {

                options.IgnoreOnInsertExpression = customer => new {customer.CustomerID,  customer.ModifiedDate};

            });

        }

        using (var context = new EntityContext())

        {

            FiddleHelper.WriteTable("After BulkInsert",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 DateTime? ModifiedDate { get; set; }

        public DateTime CreatedDate { get; set; }

        public Boolean IsActive { get; set; }

    }

}