Question

NHibernate’s Session and EF’s ObjectContext are implementations of Unit of Work pattern and suggest similar approaches for change tracking: you retrieve some entities, then modify them somehow and after that call SaveChanges/SubmitChanges/Save/etc.

I don’t like the implicitness of this approach. I don’t like that entity modification automatically means it will be saved. I would like to explicitly mark entities that should be saved. What are the best ways to achieve this kind of control in NHibernate or EF?

Answer 1

(note: fortunately I’ve never dealt with EF; my answer is about NH only)
I think your initial assumption is wrong:

entity modification automatically
means it will be saved

that’s not true; in order to persist the changes you’ve made you need to either:

1. call Session.Flush() yourself
2. set Session’s flush mode to AutoCommit (highly not recommended)
3. use an ITransaction and commit it (by far the best approach).

unless you do any of the above your changes would not be persisted.
Personally I feel that NH gives me complete control over what goes into my DB.

here’s a good article.