Hi,If the combo box is populated from the database, perhaps you could keep a detached City object around (as a value of a Map corresponding to the name of the city as the key) and when the new Address instance is created, use the detached City instance as the value of the City field in the new Address instance. When you do makePersistent on the Address, the detached City instance will be reconnected to the database.
Craig On Jun 29, 2009, at 12:54 PM, LFS wrote:
Hi This is my situation: I have an Address object that I persist/retrieve from the DB. It contains a City object, reperesenting the city on which that address is. City contains State, and State contains Country object (a long N-1 chain). When I'm creating a new address from user input, the user selected its city from a combo box which I populated from DB, then I'll have the city's ID. When I try to persist the new address, the most I can do is put a City object on it, containing only the city ID. The problem is that persisting this will erase the City record for that ID on the DB, because other fields like Name and State will be null. I want simply to set the foreign id on the Address object, nothing else. I believe there is somegood solution for this... my intention is not updating the City object,and retrieving it to put it back on the address object before being persisted sounds very strange and a performance nightmare. What's the proper way to do this? Thanks! Note: I'm using application identity and DataNucleus JDO.____________________________________________________________________________________Veja quais são os assuntos do momento no Yahoo! +Buscados http://br.maisbuscados.yahoo.com
Craig L Russell Architect, Sun Java Enterprise System http://db.apache.org/jdo 408 276-5638 mailto:craig.russ...@sun.com P.S. A good JDO? O, Gasp!
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