Are there some good known strategies for migrating data between different versions of app using hibernate.
The problem I am facing is that IDs are generated by database in the initial version. In the new version i want to use same IDs for consistency but hbm file wont allow an assigned ID.
Doing this stuff directly with importing db dump is straightforward but i want to use the object model so that rest of the system is in sync.

Any pointers?

Usually when upgrading an application I do a dump of source base (MySQL) and write (manually), a migration script that adds columns, renames tables etc.

I keep a separate migration file for every relase and apply them sequentialy.

This way you do not touch your existing entities at all. All ids are not touched at all.

Please rate if that helps.

Doing without touching the domain model with sql dump works if rdbms is the only place where data resides. In my case the domain model maps to RDBMS as well as other data sources like files, search indexes. This requires me to make all updates go through the domain model and service layer for consistency.