HowTo: construct Composite key using other composite key?

Question

Hello. I don' undestand how is it possible to do.
Please, see my code:
@Entity
@Table(name = "Person", schema = SCHEMA)
public class Person {
     @Id
     @GeneratedValue
     @Column(name = "id")
     private int id;
     private String medialogyUid;
     private String firstName;
     private String lastName;
     private String patronymic;
     private String biography;
@Entity
@IdClass(Convocation.PK.class)
@Table(name = "Convocation", schema = SCHEMA)
public class Convocation {
     @Id
     private int number;
     @Id
     @ManyToOne(fetch=FetchType.EAGER, cascade={CascadeType.MERGE, CascadeType.REFRESH, CascadeType.PERSIST})
     private Institution institution;
     private Date beginDate;
     private Date endDate;
     public Convocation(){
     public Convocation(Institution inst, int number, Date beginDate, Date endDate){
          this.institution = inst;
          this.number = number;
          this.beginDate = beginDate;
          this.endDate = endDate;
     public static final class PK implements Serializable {
          public int number;
          public int institution;
          public PK(){
          /**@param number is convocation,number
           * @param institution is convocation.institution.id
          public PK(int number, int institution){
               this.number = number;
               this.institution = institution;
          @Override
          public boolean equals(Object o) {
               if (!(o instanceof PK))
                    return false;
               PK oPK = (PK)o;
               return this.number == oPK.number && this.institution  == oPK.institution;
          @Override
          public int hashCode() {
               return ((number == 0) ? 0 : new Integer(number).hashCode()) ^ ((institution == 0) ? 0 : new Integer(institution).hashCode());
//And finally the last class:
@Entity
@IdClass(DeputyMandate.PK.class)
@Table(name = "DeputyMandate", schema = SCHEMA)
public class DeputyMandate {
     @Id
    @ManyToOne(fetch=FetchType.EAGER, cascade={CascadeType.MERGE, CascadeType.REFRESH, CascadeType.PERSIST})
     private Person person;
     @Id
     @ManyToOne(fetch=FetchType.EAGER, cascade={CascadeType.MERGE, CascadeType.REFRESH, CascadeType.PERSIST})
     private Convocation convocation;
     private Date dateIn;
     private Date dateOut;
     public static final class PK implements Serializable {
               //don't know what to use @Embeddable or what?
    }I want DeputyMandate to use composite key. This composite key is based on Person with simple key +(int id)+ and Convocation PK.
Please, tell me how can I make composite key DeputyMandate.PK using simple key from Person and composite key from Convocation.
Edited by: Holod on 27.08.2008 15:52

Answer 1

And
CONSTRAINT FK_CONFIG_OPTION_ID FOREIGN KEY (CONFIG_ITEM_ID,CONFIG_OPTION_ID) REFERENCES PRODUCT_CONFIG_OPTION(CONFIG_ITEM_ID,CONFIG_OPTION_ID)
?