Old and new values are same in audit.net

this is my controller

 using (var audit = AuditScope.Create("Devices:AddDevices", () => model))
 {
      \\\
 }

this is data provider

  Audit.Core.Configuration.DataProvider = new AzureTableDataProvider()
            {
                ConnectionString = ConfigurationManager.ConnectionStrings["AuditDbConnection"].ToString(),
                TableName = "tblbateventsauditing",
                TableEntityMapper = ev => new AuditEventTableEntity(ev)
            };

but oup put gives same Old and new values

 "Target":{  
    "Type":"Devices",
    "Old":{  
      "UserId":"",
      "IvpId":0,
      "UserName":"",
      "DeviceCode":"XXXXX",
      "PurchaseDate":"2018-09-09T00:00:00",
      "PurchasePlaceId":12,
      "Active":false,
      "UpdatedDate":"0001-01-01T00:00:00",
      "DeviceStatusId":0,
      "DateofReplacement":"0001-01-01T00:00:00",
      "DateofTransfer":"0001-01-01T00:00:00",
      "RegistrationDate":"0001-01-01T00:00:00",
      "TotalRecords":0,
      "Id":18,
      "CurrentStatusId":0,
      "TRCCode":""
    },
    "New":{  
      "UserId":"",
      "IvpId":0,
      "UserName":"",
      "DeviceCode":"XXXXXX",
      "PurchaseDate":"2018-09-09T00:00:00",
      "PurchasePlaceId":12,
      "Active":false,
      "UpdatedDate":"0001-01-01T00:00:00",
      "DeviceStatusId":0,
      "DateofReplacement":"0001-01-01T00:00:00",
      "DateofTransfer":"0001-01-01T00:00:00",
      "RegistrationDate":"0001-01-01T00:00:00",
      "TotalRecords":0,
      "Id":18,
      "Createdby":"backoffice\\systemadmin",
      "Updatedby":"backoffice\\systemadmin",
      "CurrentStatusId":0,
      "TRCCode":""
    }
  },

Can you please provide solution for this. @thepirat000

Thanks !

[BHolthuijsen]

Thanks a lot for this, it works like a charm!

Now the EventEntry.Changes contain the correct OriginalValue and NewValue.

Because the logic we’re using sets the state of the item to “EntityState.Modified” before saving, all columns are included in the Changes. This is not an Audit.NET issue, but is caused by our own code.

Since the addition of ReloadDatabaseValues, we can filter the audit data before writing it to the database. (AuditLog is our generic logging table)

Audit.Core.Configuration.Setup()
            .UseEntityFramework(_ => _
            .AuditTypeMapper(t => typeof(AuditLog))
            .AuditEntityAction<AuditLog>((ev, entry, entity) =>
            {
                entity.Schema = entry.Schema;
                entity.Name = entry.Table;
                entity.Key = Convert.ToInt64(entry.PrimaryKey?.FirstOrDefault().Value);
                // set the action: I(nsert), U(pdate), D(elete)
                entity.Action = entry.Action?.Substring(0, 1);
                entity.LogDate = DateTimeOffset.Now;

                // remove all the changes where the old and new values are the same
                entry.Changes.RemoveAll(change => object.Equals(change.OriginalValue, change.NewValue));
                entity.Changes = entry.ToJson();
            })
            .IgnoreMatchedProperties(true)
            );

[thepirat000]

Starting from version 21.0.2, the Audit.EntityFramework and Audit.EntityFramework.Core libraries introduce a new feature.

The setting called ReloadDatabaseValues can be globally or individually configured for a DbContext instance. It determines whether the original values of audited entities should be fetched from the database prior to saving the audit event.

Consider the following examples of update and delete operations:

using (var context = new MyAuditedContext())
{
    //context.ReloadDatabaseValues = true;

    context.Cars.Update(new Car() { Id = 123, Name = "New name" });
    await context.SaveChangesAsync();
}

using (var context = new MyAuditedContext())
{
    //context.ReloadDatabaseValues = true;

    context.Entry(new Car() { Id = 123 }).State = EntityState.Deleted;
    await context.SaveChangesAsync();
}

If the ReloadDatabaseValues is not set to true, the EF Change Tracker will lack knowledge of the original values.

Enabling the ReloadDatabaseValues setting triggers an extra database query to retrieve the original values prior to the update operation. As a result, the audit event will contain the original values.