What id value indicates detached?

[chornsey]

If i create a new instance of an object, then try and persist it the following exception is raised.

org.hibernate.PersistentObjectException: detached entity passed to persist

I know what the error is meant to indicate, but I want to know how JBoss makes the determination that it has been persisted.

For non-primatives I would assume null indicates that the object has not ben persisted yet, but what about primitives? 0, negative 8, better yet 42 ??

Thanks all

[mazz]

Use 0 (zero)

[epbernard]

no,
the rules are:
null
or the value == the value found in a new Instance().getId()
or the version value == the value found in a new Instance().getVersion()
(some other rules)
if all fails, we go to the DB to check