JPA One to One Mapping problem

Question

[Please see Image|http://caterpillar.onlyfun.net/Gossip/EJB3Gossip/images/OneToOneSharedPK-1.jpg]
The primary key (@PrimaryKeyJoinColumn ) cannot join to 'Room Table'.
what mistake?
@Entity
@Table(name="T_USER")
public class User implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
   @Column(name = "USER_ID")
    private Integer userId;
    @Column(name = "NAME")
    private String name;
    @Column(name = "AGE")
    private String age;
    @OneToOne(cascade=CascadeType.ALL)
    @PrimaryKeyJoinColumn(name="USER_ID" , referencedColumnName="ROOM_ID")
    private Room room;
   // getter and setter missing
@Entity
@Table(name="T_ROOM")
public class Room implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ROOM_ID")
    private Integer roomId;
    @Column(name = "ADDRESS")
    private String address;
// getter and setter missing
}Edited by: lauangus on 2010?4?21? ??3:24

Answer 1

There are several things missing here.
For serializable, you should always have a unique:
private static final long serialVersionUID =1234L;
Here is an example that actually works, adapted to your classes:
@OneToOne( cascade = CascadeType.REFRESH, optional = false )
@JoinTable( name = "USER_ROOM", joinColumns = @JoinColumn( name = "USER_ID" ),
inverseJoinColumns = @JoinColumn( name = "ROOM_ID" ) )
You may also want to investigate the following annotations depending on your DB:
@GeneratedValue
@SequenceGenerator
You may want to generate your case using beanwizard.com to see how a working version is configured.