One more thing, setting
q.setHint(QueryHints.HINT_IGNORE_PREPARED_QUERY, queryString);
seems to make it work always, so I tend to believe this is a bug in OpenJPA,
or?
Thanks... Dominik.
On Sat, Dec 4, 2010 at 10:20 PM, Dominik Stadler <[email protected]>wrote:
> Hi,
>
> I have a problem in my application where a query that sometimes returns
> data and sometimes not.
>
> I have reduced it to the code as much as I could into an Eclipse project
> available at http://ubuntuone.com/p/S9n/
>
> This uses OpenJPA 2.0.1 and a out-of-process Derby database.
>
> Basically I have two Entities which both use multiple Ids to produce the
> Primary Key, "Preis" contains a foreign key on "Website":
>
> @Entity
> @IdClass(MandantAndNameIdentity.class)
> public class Website {
> @Id
> private String mandant;
>
> @Id
> private String name;
> ...
> }
>
> @Entity
> @IdClass(WebsiteProduktDatumIdentity.class)
> public class Preis {
> @Id
> @ManyToOne(cascade = CascadeType.MERGE)
> private Website website;
>
> @Id
> @Basic
> private String datum;
> ...
> }
>
> I use the following to set up a website and a Preis:
>
> em.getTransaction().begin();
>
> Website website = em.merge(new Website("Mandant", "Website"));
>
> em.merge(new Preis(website, DATUM));
>
> em.getTransaction().commit();
>
> Afterwards, if I run the query as follows:
>
> TypedQuery<Preis> q = em.createQuery(
> "select m from Preis m " +
> "where m.website.name = :website ", Preis.class);
> q.setParameter("website", website.getName());
>
> this query works all the time, note that it uses website.name for
> matching, not the full Website-object.
>
> However if I put the query as
>
> TypedQuery<Preis> q = em.createQuery(
> "select m from Preis m " +
> "where m.website = :website ", Preis.class);
> q.setParameter("website", website);
>
> it only works ONCE and then does not return any results any more!! See
> testcase DataAccessVerifyTest for details.
>
> Is this a dummy dumb user error? Or do I miss something basic in JPA? Or is
> this in fact a misbehavior of OpenJPA?
>
> Thanks... Dominik.
>
>
