Hi experts,
I have two database tables with a foreign key constraint and generated JPA-entities for them:
@Entity
public class Verdeck implements Serializable {
@EmbeddedId
private VerdeckPK pk;
@Column(name="ID_VERDECK")
private String idVerdeck;
@OneToMany(mappedBy="verdeck")
@PersistenceContext
private Set<Uzsb> uzsbCollection;
...
}
@Embeddable
public class UzsbPK implements Serializable {
@Column(name="ID_UZSB")
private String idUzsb;
@Column(name="ID_PROJECT")
private BigDecimal idProject;
...
}
Furthermore I have a SessionBean implementing a query in one of its business methods:
@WebMethod(operationName="getVerdeckData", exclude=false)
public List<Verdeck> getVerdeckData (@WebParam(name="searchkey")
BigDecimal searchkey){
Query q = em.createQuery("SELECT v FROM Verdeck v WHERE v.pk.idProject = :searchkey")
.setParameter("searchkey", searchkey);
return q.getResultList();
}
When calling the method via WebService-Navigator I get this error:
"com.sap.engine.services.webservices.espbase.server.additions.exceptions.ProcessException: The relationship >>uzsbCollection<< of entity (com.karmann.r57schraub.jpa.Verdeck(idProject=57, idIntern=v1))cannot be loaded because the entity is detached"
(idProject / idIntern) is the composed key of "Verdeck" and (57 / v1) is a concrete value for this key in the database table.
If required I could give you classes VerdeckPK and UzsbPK as well.
Could you please explain what I'm doing wrong?
Thanks for each hint,
Christoph