JPA2: Possiamo usare più @elementCollection in un'entità?

Question

Ecco la versione down stripped del mio codice:

@Entity
public class Item implements Serializable{

@Id
@GeneratedValue
private long id;

@ElementCollection(fetch=FetchType.EAGER ,targetClass=Cost.class)
@CollectionTable(name="ItemCost", joinColumns = {@JoinColumn(name="itemId")})
private Set<Cost> costs= new HashSet<Cost>();

@ElementCollection(fetch=FetchType.EAGER ,targetClass=ItemLocation.class)
@CollectionTable(name="ItemLocation", joinColumns = {@JoinColumn(name="itemId")})
private Set<ItemLocation> itemLocations;

}

.

è il codice sopra consentito?Ho due costi e lezioni incorporabili e itemloution che sto usando con @elementcollection.

Problema: Quando provo a eseguire una query denominata

@NamedQuery(name = "Item.findAll", query = "SELECT i FROM Item i")

.

Ho un comportamento strano.I record nella seconda elementazione degli elementi (tabella ItemLCCation) vengono raddoppiati (inseriti nella tabella).

Answer 1

What it comes to JPA 2.0, your code is allowed. It is perfectly legal to have more than one collections that are annotated with ElementCollection. Also, it most likely does not have anything to do with problem you have. By the way, to find out is that really your problem, had you tried your code without costs collection?

In which point exactly duplicates in this collection occur first time? If ItemLocation does not define equals&hashcode, duplicates can easily come as result of adding items by yourself.

Possibly you are facing this problem: Primary keys in CollectionTable and chancing type to list and adding @OrderColumn will help.