Hi every,

Let say the entity is already in DB and in the code I created a new instance with only some of the fields set (including the identifier). Is it possible to direct hiberate to update or merge only non-null fields to the persistent object? Since some fields are not set in the newly created object, they are set to null by hibernate. :/

Kindly Regards,
Quincy

Hibernate, or your own code if you would implement this directly, would need a way to understand what you did set, and what you did not define, so in both cases you should start by loading the original entity, and set the fields to be changed. Hibernate will then compare the old values with the new values, and perform the needed update statements.

So:
1) start a transaction
2) load the entity to be changed
3) apply changes on it
4) commit the transaction

If you also need the update statement to not rewrite unchanged fields/columns, search also for dynamic-update in the reference documentation.