插入JPA集合而不加載它

Question

我目前正在使用這樣的代碼向我的實體中的集合添加一個新條目。

player = em.find(Player.class, playerId); 
player.getAvatarAttributeOwnership().add(new AvatarAttributeOwnership(...)); 

它的工作原理，但每次我想添加一個項目，整個集合加載。

1. 有沒有一種方法（與查詢也許）添加項目而不加載其餘的？在SQL中，它將類似INSERT INTO AvatarAttributeOwnership(player, data, ...) VALUES({player}, ...);
2. 目前唯一性由Set和AvatarAttributeOwnership.equals的合同維護，但我認爲這將不再有效。我怎樣才能執行它呢？

我正在使用JPA2 + Hibernate。代碼：

@Entity 
public class Player implements Serializable { 

    @Id 
    @GeneratedValue 
    private long id; 

    @ElementCollection(fetch=FetchType.LAZY) 
    // EDIT: answer to #2 
    @CollectionTable(uniqueConstraints=@UniqueConstraint(columnNames={"Player_id","gender","type","attrId"})) 
    Set<AvatarAttributeOwnership> ownedAvatarAttributes; 

    ... 

} 

@Embeddable 
public class AvatarAttributeOwnership implements Serializable { 

    @Column(nullable=false,length=6) 
    @Enumerated(EnumType.STRING) 
    private Gender gender; 

    @Column(nullable=false,length=20) 
    private String type; 

    @Column(nullable=false,length=50) 
    private String attrId; 

    @Column(nullable=false) 
    private Date since; 

    @Override 
    public boolean equals(Object obj) { 

     if (this == obj) return true; 
     if (obj == null) return false; 
     if (getClass() != obj.getClass()) return false; 

     AvatarAttributeOwnership other = (AvatarAttributeOwnership) obj; 

     if (!attrId.equals(other.attrId)) return false; 
     if (gender != other.gender) return false; 
     if (!type.equals(other.type)) return false; 

     return true; 
    } 

    ... 

} 

Answer 1

嘗試extra-lazy collections：

@LazyCollection(LazyCollectionOption.EXTRA)