Skip to Content
0
Former Member
Jan 03, 2008 at 04:15 PM

JPA: Error "entity is detached" when executing a query

134 Views

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