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From "Ram.sankar" <>
Subject Re: Issue in Handling persistent objects across multiple persistence contexts
Date Tue, 10 Mar 2009 04:57:37 GMT

Yes rick, i am using merge only, please have a look at the below code:

		DataObject bean = writeEm.merge(beanVar);

writeEm = EntityManager for writing alone
om = entityManager for reading alone


Rick Curtis wrote:
> Ram -
> When you want to write your detached Entity back to the DB, are you using
> EntityManager.merge(..)? If not, I'd give that a try.
> -Rick
> Ram.sankar wrote:
>> Hi,
>> In my application i have a requirement that eventhough i change the
>> values of persistent objects available in the session directly using
>> getter and setter methods i have to save only the objects on which the 
>> EntityManager.persist() is invoked explicitly. To resolve this problem we
>> maintain 2 managers one for read and another for write. I detach the
>> object from the read entity manager and merge the same with the write
>> entity manager before calling a persist(). 
>> The problem here is that OpenJPA is generating an insert query to save
>> the persistent object eventhough it exists in the table. This is giving
>> me an Unique constraint violated error. Is there anyway to tell OpenJPA
>> to check for the existence of record with same primary key before
>> persisting. Any help is highly appreciated.
>> Regards,
>> Ram

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