// @nuget: EntityFramework

// @nuget: Z.EntityFramework.Plus.EF6

​

using System;

using System.Collections.Generic;

using System.Linq;

using System.Data.Entity;

using Z.EntityFramework.Plus;

​

public class Program

{

    public static void Main()

    {

        GenerateData(); 

​

        // Audit : Using a different context.

        AuditManager.DefaultConfiguration.AutoSavePreAction = (context, audit) =>

        {

            var sqlServerContext = new SqlServerContext();

            sqlServerContext.AuditEntries.AddRange(audit.Entries);

            sqlServerContext.SaveChanges();

        };

        // Audit : Easily tracks changes, exclude/include entity or property and auto save audit entries in the database.

        using (var context = new EntityContext())

        {  

            var listToRemove = context.Customers.Where(x => x.IsActive == false ).ToList();

            var listToModify = context.Customers.Where(x => x.IsActive == true ).ToList();

            var listToAdd = new List<Customer>() { new Customer() { Name = "Customer_C", Description = "Description", IsActive = false}};

            context.Customers.AddRange(listToAdd); // add

            context.Customers.RemoveRange(listToRemove); // remove

            listToModify.First().Description = "Updated_A"; // modify

            var audit = new Audit();

            audit.CreatedBy = "ZZZ Projects"; // Optional

            context.SaveChanges(audit);  

        }

        Customer customerToRetrieve = null;

        using (var context = new EntityContext())

        {

            customerToRetrieve = context.Customers.First();

        }

        using (var context = new SqlServerContext())

        {

            var auditEntries = context.AuditEntries

                .Where(x => x.EntityTypeName == typeof(Customer).Name && x.Properties.Any(y => y.PropertyName.ToString() == "CustomerID" && (y.OldValueFormatted == customerToRetrieve.CustomerID.ToString() || y.OldValueFormatted == customerToRetrieve.CustomerID.ToString())))      

                .Include(x => x.Properties)

                .ToList();

            FiddleHelper.WriteTable("AuditEntries:", auditEntries);

            FiddleHelper.WriteTable("AuditEntryProperties:", auditEntries.SelectMany(x => x.Properties));

        }

    }

    public static void GenerateData()

    {

        using (var context = new EntityContext())

        {

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

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

            context.SaveChanges();  

        }

    }

    public class EntityContext : DbContext

    {

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

        {

​

        } 

        public DbSet<Customer> Customers { get; set; }

    }

    public class SqlServerContext : DbContext

    {

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

        {

​

        } 

       // ... context code ...

       public DbSet<AuditEntry> AuditEntries { get; set; }

       public DbSet<AuditEntryProperty> AuditEntryProperties { 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; }

    }

}