According to documentation just before saving entity to datasource an instance of NumericIdGenerator is called to retrieve the real Id for this entity. Saving entity is a transaction, so if something goes wrong I would like to rollback not only this transaction, but also to rollback the id, which I retrieved from datasource using NumericIdGenerator. The problem is that I can't rollback id retrieval because NumericIdGenerator gets a new connection to datasource and commits its transaction independently of parent entity saving transaction.

The same issues become important also during handling Saving event. If something goes wrong after handling Saving event I will have no possibilities to rollback handling code.

Is there any way to get over this difficulty?

 

When I ask NumericIdGenerator to generate next id, it allocates ids using AdoHelper's new connection: it selects next id and then UPDATES nextid counter to the NEW value. If save transaction is rolled back after updating - id counter value won't be rolled back to the OLD value because NEW value of id counter is already comitted to the datasource.

What I want is to rollback id counter value (or something else in "Saving: handler for example) - the nested transaction - in case of parent transaction rollback

 

I hope that would be optional/configurable.

 

Many of our applications use an 'odometer' class which my initial inquiries show will map well to your Id generators (with a few mods in the classes implementing IIdGenerator).

 

But our applications rely on the behaviour currently exhibited as discussed above.

When a transaction fails in our applications, most of the time(read always), we do not want to rollback the odometer as another user or process may already have taken the next id.

 

The alternative would be to hold up process B until process A's transaction was completed (either way).

 

Perhaps I'll change my mind after playing more with client side caching ???