JPA2: Peut-on utiliser plusieurs @ElementCollection dans une entité?

Question

Voici la version supprimée de mon code:

@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;

}

est le code ci-dessus autorisé?J'ai deux classes embarquables coût et itemlocation que j'utilise avec @ElementCollection.

problème: Quand j'essaie d'exécuter une requête nommée

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

J'ai un comportement étrange.Les enregistrements dans le deuxième élémentCollection (Table itemlccation) sont doublés (insérés dans la table).

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.