It seemed easier in my situation to delete everything and re-insert. I did
go ahead and do an update (and that works) but I had to add a bunch of logic
that checks if some of records are new (so are straight inserts) or exist
(and are updates) or exist and need to be removed. I was hoping to not have
to write all of that logic and just delete the existing records then insert
with the new data that is passed in.
Axl Mattheus-2 wrote:
>
> Why do you delete the entity and not update it instead?
> ...
> anEntity.setValue(whatever);
> em.merge(anEntity);
> ...
>
>
> 2009/1/24 sonavor <jw_at_worleytown.com>
>
>>
>> I am having trouble trying to resolve a problem with an application that
>> uses
>> an EJB 3 stateless session EJB as a DAO for some JPA entity beans. For
>> one
>> business rule I need a method in the session EJB to delete existing
>> entity
>> beans for a submitted key and insert a new set of entity beans passed to
>> the
>> method. It is possible and likely that some of the new entity beans
>> could
>> have a primary key that is the same as one of the deleted entities.
>>
>> I tried this -
>>
>> MyEntityTestPK e1PK = new e1PK(someValue1, someValue2);
>>
>> MyEntity1 anEntity = em.find(MyEntity1.class, e1PK);
>> if ( anEntity != null ) {
>> em.remove(anEntity);
>> }
>>
>> ...later in the same method I insert an entity -
>>
>> MyEntity1 anotherEntity = new MyEntity();
>> anotherEntity.setPk(e1PK);
>> anotherEntity.setValue1(somevalue)
>>
>> em.persist(anotherEntity);
>>
>> ...This produces an exception complaining of a duplicate key. I also
>> tried
>> doing a merge but that generates a "cannot persist detached object"
>> exception.
>>
>> What are the proper steps to delete records then create records again in
>> the
>> same transaction with (occasionally) the same primary key value?
>>
>>
>> --
>> View this message in context:
>> http://www.nabble.com/JPA-with-EJB3---remove-an-entity-and-create-new-entity-with-same-primary-key-%28same-transaction%29-tp21639342p21639342.html
>> Sent from the java.net - glassfish persistence mailing list archive at
>> Nabble.com.
>>
>>
>
>
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