Problem with Disconected objects

segdae22 · **Joined:** Tue Nov 04, 2008 5:02 pm **Posts:** 4

I'm having some problems with NHibernate commiting my object changes back to the database. I have an object framework that utilizes NHibernate and the UI interacts with these objects via a WCF service, so I need to operate in a disconnected environment (since I don't want to manage the session on the individual objects). I have no problem retrieving data from the database but I can't seem to persist it back if I disconnect the object from the session and then try to reconnect it later (as a side note, i've tried committing to the database while in the same session and it does work so I know there's no problem with the mapping files etc). Here is the code I use to create the object:

Code:

public static T Get(int id)
        {
            using (ISessionFactory factory = new Configuration().Configure().BuildSessionFactory())
            {
                using (ISession session = factory.OpenSession())
                {
                    return (T)session.Load(typeof(T), id, LockMode.Upgrade);
                }
            }
        }

When I attempt to save the object, I use the following:

Code:

public virtual void Save()
        {
            if (this.ID != null)
                this.DateEdited = DateTime.Now;
            else
                this.DateAdded = DateTime.Now;

            using (ISessionFactory factory = new Configuration().Configure().BuildSessionFactory())
            {
                using (ISession session = factory.OpenSession())
                {
                    using (ITransaction transaction = session.BeginTransaction())
                    {
                        session.Lock(this, LockMode.None);
                        session.SaveOrUpdate(this);
                        transaction.Commit();
                    }
                    session.Flush();
                }
            }
        }

I don't get any errors when I save and it appears to work fine (no exceptions etc) but no data is actually saved back to the database. Can someone clue me in on what I'm missing? I've been over all the documentation and from what I can tell, I'm doing everything correctly. I've tried experimenting with different lockmodes but none of them seem to do the trick.

Thanks,

gonzao_diaz · **Joined:** Mon Nov 26, 2007 2:29 pm **Posts:** 443

use merge() instead of first lock(), then saveOrUpdate().

segdae22 · **Joined:** Tue Nov 04, 2008 5:02 pm **Posts:** 4

FYI - I had to eliminate the session.Lock() call and change the SaveOrUpdate to SaveOrUpdateCopy. The final code looks like this and works as expected:

Code:

public virtual void Save()
        {
            if (this.ID != null)
                this.DateEdited = DateTime.Now;
            else
                this.DateAdded = DateTime.Now;

            using (ISessionFactory factory = new Configuration().Configure().BuildSessionFactory())
            {
                using (ISession session = factory.OpenSession())
                {
                    using (ITransaction transaction = session.BeginTransaction())
                    {;
                        session.Merge(this);
                        session.SaveOrUpdateCopy(this);
                        transaction.Commit();
                    }
                    session.Flush();
                }
            }
        }

Thanks for the help!

giuliob · **Joined:** Mon Nov 10, 2008 6:42 am **Posts:** 1

Thanks for posting your solution. It solved also my
"NotUniqueObjectException: a different object with the same identifier value was already associated with the session".
My Dao-Code (C#, NHibernate 2.0 and Spring.NET 1.2.0 RC1)

Code:

public Art  SaveOrUpdate(Art art)
      {
         using ( ITransaction trx = sessionFactory.GetCurrentSession().BeginTransaction() )
         {
            sessionFactory.GetCurrentSession().Merge(art);
            sessionFactory.GetCurrentSession().SaveOrUpdateCopy(art);
            trx.Commit();      
         }
         sessionFactory.GetCurrentSession().Flush();
         return art;      
      }