Generating trigger-based auditing

Another approach to auditing involves tracking each change to an entity in a separate audit table. In this recipe, we will show you how to use NHibernate to generate audit triggers for your entity tables.

Getting ready

Download uNHAddIns.dll from the unofficial NHibernate AddIns project at https://bitbucket.org/fabiomaulo/unhaddins. Save the file to your solution's Lib folder.

How to do it…

1. Create a new console application project with all standard NHibernate references, the standard NHibernate and log4net configuration, and the Eg.Core model from Chapter 1, The Configuration and Schema.
2. Add a reference to uNHAddIns.dll.
3. Set the dialect to uNHAddIns.Audit.TriggerGenerator.ExtendedMsSql2008Dialect, uNHAddIns.
4. Add the following code to the Main method of Program.cs:

   var cfg = new Configuration().Configure();
   
   var namingStrategy = new NamingStrategy();
   var auditColumnSource = new AuditColumnSource();
   new TriggerAuditing(cfg, namingStrategy,
     auditColumnSource...