Good Morning, I had this often and one solution is to set the FetchType to EAGER for the Relationship.
Cheers, John > -----Ursprüngliche Nachricht----- > Von: Marc Logemann [mailto:m...@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 > > > > >
