#3295 Clear PersistenceContext on execution of bulk updates or deletes

[rbygrave]

Using SqlUpdate or an ORM Update query clear the appropriate part of the PersistenceContext. The effect is that ORM queries executed after a bulk update will effectively load a fresh copy of the data from the database and will not reuse an instance from the persistence context if the bean in question had already been loaded.

[jnehlmeier]

bean2 and bean5 should be the same which could be asserted as well.

Before merging this we might want to think about JPA again. I am not 100% sure but I think this change could cause trouble for people who have migrated to ebean using your JPA mode. If the per transaction entity cache works differently in ebean as in JPA this could lead to hard to diagnose side effects.

[rbygrave]

which could be asserted as well.

Yes nice. I've added that.

could cause trouble for people who have migrated to ebean using your JPA mode

So that mode is called autoPersistUpdates and effectively set on the transaction. I do believe this change does not really work when autoPersistUpdates = true or at least it could be very confusing. For now I've made a change to this PR so that this Persistence Context clearing only occurs when autoPersistUpdates = false.

Hmm.

[rbygrave]

I'm feeling comfortable that this PR should be merged in with the next major version (so 14).

JPA mode / autoPersistUpdates = true

I'm feeling some regret about adding that feature. Also just to say Gavin is keen on getting "Stateless Session" functionality into JPA 4 which is all about explicit insert, update, delete etc.