openjpa-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Boblitz John <John.Bobl...@BERTSCHI.com>
Subject AW: update null relation on merge()
Date Fri, 24 Aug 2012 09:50:45 GMT
Which detached state are you using?

> -----Urspr√ľngliche Nachricht-----
> Von: Marc Logemann [mailto:li@logemann.org] 
> Gesendet: Freitag, 24. August 2012 11:43
> An: users@openjpa.apache.org
> Betreff: Re: update null relation on merge()
> 
> 1:1 relations are eager by default.... And eager could be 
> only a loading issue. I have a "merge" issue here.
> 
> ---
> regards
> Marc Logemann
> http://www.logemann.org
> http://www.logentis.de
> 
> 
> 
> 
> Am 24.08.2012 um 11:28 schrieb Boblitz John 
> <John.Boblitz@BERTSCHI.com>:
> 
> > Good Morning,
> > 
> > I had this often and one solution is to set the FetchType 
> to EAGER for 
> > the Relationship.
> > 
> > Cheers,
> > 
> > John
> > 
> >> -----Urspr√ľngliche Nachricht-----
> >> Von: Marc Logemann [mailto:ml@logemann.org]
> >> Gesendet: Freitag, 24. August 2012 11:17
> >> An: users@openjpa.apache.org
> >> Betreff: update null relation on merge()
> >> 
> >> Hi,
> >> 
> >> i am facing something like described here:
> >> 
> >> http://openjpa.208410.n2.nabble.com/null-values-not-updating-t
> >> d3224059.html
> >> 
> >> We get a JSON graph from frontend, let Spring deserialize it to a 
> >> java object (with OID set) and want to change the existing 
> object in 
> >> the db. This works for simple attribtues likes Strings and 
> so but not 
> >> for 1:1 relations. If we set it to "null" in the frontend, 
> we want to 
> >> change the 1:1 relation to null. Instead it leaves the 1:1 
> relations 
> >> untouched with the old object reference in it.
> >> 
> >> The OpenJPA docs once said: "When attaching null fields in these 
> >> cases, OpenJPA cannot distinguish between a field that was 
> unloaded 
> >> and one that was intentionally set to null. In this case, OpenJPA 
> >> will use the current detach state setting to determine how 
> to handle 
> >> null fields: fields that would have been included in the detached 
> >> state are treated as loaded, and will in turn set the 
> corresponding 
> >> attached field to null."
> >> 
> >> At this point i dont know what to do. Spring knows its detached 
> >> because we submit our @Id Field => OID with a valid and existant 
> >> value but the merge itself just ignores null values for 
> 1:1 relations 
> >> and leaves them as they were. Is there any sensible way to tell 
> >> OpenJPA to merge "null"
> >> relations differently?
> >> 
> >> ---
> >> regards
> >> Marc Logemann
> >> http://www.logemann.org
> >> http://www.logentis.de
> >> 
> >> 
> >> 
> >> 
> 
> 
Mime
View raw message