@Version optimistic locking and timestamp

mgrouch · **Joined:** Thu Aug 04, 2005 8:41 pm **Posts:** 47

I'm trying to use @Version on a version field which is declared as timestamp in Sybase.
This timestamp is generated by database, however hibernate tries to manage its value (insert,). In hbm.xml files there are ways to specify it as generated by database with source=db generated=always.
What is the way to achieve same with annotations?

Thanks

emmanuel · **Posted:** Tue Jun 05, 2007 4:56 pm

I don't think it's supported yet, try @Type(type="dbtimestamp")
with @Generated(ALWAYS), it might work

kgraham00 · **Joined:** Sun Jul 08, 2007 12:10 pm **Posts:** 2

I can get this feature to work with this set of annotations on the version field:

Code:

@Version
@Column(insertable = false, updatable = false)
@Generated(GenerationTime.ALWAYS)
private Timestamp versionDate;

With the above annotations, I can use a Date or Timestamp type which is populated solely by the database (Oracle in this case).

However, in my domain, versionDate is really a last modified date. When new instances are created, this field is null and is only populated after an UPDATE is executed. How do I let the system know that null is the initial version? Or is there an alternative?

Thanks,

Kevin