Hi Mike, We run into this issue. but in our case, we only use local EJBs, why the entities get serialized and deserialized?
thanks mikedd wrote: > > Hi > > I've seen this happen when an entity is serialized and deserialized. > During > the serialization process the State of the entity was lost. So when the > entity was reattached OpenJPA couldn't differentiate between an unloaded > field and one that was intentionally set to null. > > To resolve the problem you can add the following property to > persistence.xml > : > > <property name="openjpa.DetachState" > value="fgs(DetachedStateField=true)" /> > > The real key here is the DetachedStateField=true part which instructs > OpenJPA to save the State of the entity when it is serialized and > deserialized. > > This option needs to be in your persistence.xml when the entities are > enhanced. If you use static enhancement via the PCEnhancer tool you'll > have > to re-run the tool after updating persistence.xml. If you don't use static > enhancement the container will enhance your entities for you - so you'll > just need to redeploy. > > Hope this helps, > -Mike > > On Fri, Mar 7, 2008 at 2:28 PM, <[EMAIL PROTECTED]> wrote: > >> Yes, that's exactly what I am seeing, and perhaps I didn't give enough >> detail... >> >> In my case, the EJB service fetches the entity, it gets detached when it >> moves from the EJB container to the web tier, user updates the entity, >> pass >> it back to the service where it's "merged"... the fields that were nulled >> are not getting persisted. It has to do with detaching the entity then >> re-attaching it again. >> >> I've found a HACK (emphasis on HACK) to solve it in the interim.. I >> basically take the detached entity, re-fetch the managed one, copy >> properties from the detached to the managed entity, then let the managed >> entity persist normally. But it gets tedious when you're dealing with >> entities with 30-40 attributes and you can't use the Commons >> copyProperties >> because of version columns, etc. (fields that are restricted). >> >> If there is a better solution, I'd be more than happy to entertain it! >> >> Thanks! >> Randy >> > >> > From: Tedman Leung <[EMAIL PROTECTED]> >> > Date: 2008/03/07 Fri PM 01:34:32 CST >> > To: users@openjpa.apache.org >> > Subject: Re: Newly null fields not being persisted? >> > >> > I reported this as a bug earlier and I never heard back, it still >> occurs. >> > A more detiled explanation of what I found is as follows : >> > >> > - If you have a new entity with null fields, the fields will save as >> null. >> > >> > - If you have an entity which is attached, you can nullify fields as >> long >> > as it persists itself. i.e. without you calling the merge method. >> > >> > - If you retrieve an entity and detach it, then null a field, then >> > reattach it (with merge), it will not nullify the field. >> > >> > >> > if anyone knows the code well enough to fix it or point me to the area >> > where the logic of this is done that would be good. >> > >> > >> > >> > On Fri, Mar 07, 2008 at 01:28:40PM -0600, [EMAIL PROTECTED] wrote: >> > > All, >> > > >> > > I'm not sure if this is a problem in MY code or OpenJPA. But, here >> are the symptoms in WAS w/ EJB Feature pack: >> > > >> > > User enters data into a form that is backed by a managed OpenJPA >> entity. Entity gets persisted successfully. User goes back to the same >> page and nullifies one of the fields (i.e., deletes a value from one of >> the fields in the form). Entity gets persisted, but, the field that was >> nulled out is not updated. >> > > >> > > Looking at the generated SQL in the WAS log, I see the first update >> that added the data, but in the second update statement, the field that >> was >> nulled is not included in the update (thus leaving data in the underlying >> table). >> > > >> > > Is there a setting in OpenJPA that turns this off? Or, could it >> (most >> likely) be a problem in my code somewhere? >> > > >> > > Any suggestions on how I can track this down and eliminate it? >> > > >> > > Cheers! >> > > Randy >> > > >> > >> > -- >> > Ted Leung >> > >> [EMAIL PROTECTED] >> > >> > You know things are getting a little fishy when you're commenting out >> > comments. >> > >> >> > > -- View this message in context: http://www.nabble.com/Newly-null-fields-not-being-persisted--tp15904016p15908495.html Sent from the OpenJPA Users mailing list archive at Nabble.com.
