c# - Audit Logging Inserts -

i wondering if offer input implementation of audit logging inserts. need ensure transactional.

i have audit dbset built upon following poco:

public class audit {     public int id { get; set; }     public user user { get; set; }     public datetime created { get; set; }     public string type { get; set; }     public int entityid { get; set; }     public string message { get; set; } } 

i have dbset, users, when insert want create automatically add audit entity in audit dbset. consider following code:

//var user = new user(); //user.created = datetime.now; //user.username = "testuser"; //user.password = "testpassword"; //datacontext.users.add(user);  var post = new post(); post.created = datetime.now; post.title = "a sample post"; post.published = true; post.body = "some content goes in here...";  datacontext.posts.add(post);  var audit = new audit(); audit.created = datetime.now; audit.user = currentuser.user; // logged in user audit.type = "post.add"; audit.entityid = post.id; audit.message = "new post created";  datacontext.audits.add(audit);  datacontext.savechanges(); 

in instance, audit entity added "entityid" property set 0 (default value) , not identity of created user post, i.e. identity value (scope_identity()/@@identity).

i'd keep both points in single transaction, rather split items 2 transactions, i.e. persist user post first, persist audit second there chance audit may fail.

override dbcontext.savechanges() , @ changetracker.entries().where(e=>e.state != entitystate.unchanged).

here example r&d project of mine:

public override int savechanges() {     int recordsupdated = 0;      var journalentries = new list<auditjournal>();      foreach (var entry in this.changetracker.entries<itrackedentity>().where(e=>e.state != entitystate.unchanged))     {         auditjournal journal = new auditjournal();         journal.id = guid.newguid();         journal.entityid = entry.entity.id.value;         journal.entitytype = entry.entity.entitytype;         journal.actiontype = entry.state.tostring();         journal.occurredon = datetime.utcnow;         //journal.userid = current user         //journal.previousentitydata = xml serialization of original entitty          journalentries.add(journal);     }      using (var scope = new transactionscope())     {         recordsupdated = base.savechanges();          foreach (var journalentry in journalentries)             this.auditjournal.add(journalentry);          base.savechanges(); //save journal entries          scope.complete();     }      return recordsupdated; }  //every entity needs audited has implement interface public interface itrackedentity {     string entitytype { get; }     guid? id { get; set; } }