Is it possible to update selective columns in the database?

Let's say I have a User class with the following properties:
ID
Name
Phone

Let's say that I want to change the Phone. The pesudo code is
user.Phone = newPhone;
session.Update(user);

This works.

But let us say that I have a business rule that the Phone may not be updated together with the Name. The client programmer may inadvertently make a coding mistake like this:

user.Phone = newPhone;
user.Name = newName;
session.Update(user);

This would be a violation of the business rule because it will update both Name and Phone fields at the same time. How can I ignore the Name change and only update Phone?

It would appear that it can be done this way as described in Chaper 13 of Hibernate doc like below. Unfortunately, NHibernate does not yet implement the executeUpdate() method.

Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();

String hqlUpdate = "update Customer c set c.name = :newName where c.name = :oldName";
// or String hqlUpdate = "update Customer set name = :newName where name = :oldName";
int updatedEntities = s.createQuery( hqlUpdate )
.setString( "newName", newName )
.setString( "oldName", oldName )
.executeUpdate();
tx.commit();
session.close();

You cannot get NHibernate to ignore a column. You'd have to do that using raw SQL.

You can fake it by using this pseudocode:Just as an FYI, you can put dynamic-update="true" on the class mapping to get hibernate to update only the changed columns. This won't help you ignore certain changes, it just reduces the amount of output SQL, at the cost of dynamically generating the update SQL.

You cannot get NHibernate to ignore a column. You'd have to do that using raw SQL.

By raw SQL, do you mean direct access to the database outside of NHibernate?


You can fake it by using this pseudocode:
tempPhone = user.Phone;
session.Refresh(user);
user.Phone = tempPhone;
session.Update(user);

Thanks. I will try this.

Direct SQL access using the NHibernate connection. In Hibernate, it would be using session.connection(); I don't know what the equivalent in NHibernate is.