3.2.6. 複合プライマリおよび外部キーのマッピング

@Entity
public class RegionalArticle implements Serializable {

    @Id
    public RegionalArticlePk getPk() { ... }
}

@Embeddable
public class RegionalArticlePk implements Serializable { ... }

@Entity public class RegionalArticle implements Serializable {

    @EmbeddedId
    public RegionalArticlePk getPk() { ... }
}

public class RegionalArticlePk implements Serializable { ... }

@Entity
public class Parent implements Serializable {
    @Id
    public ParentPk id;
    public int age;

    @OneToMany(cascade=CascadeType.ALL)
    @JoinColumns ({
        @JoinColumn(name="parentCivility", referencedColumnName = "isMale"),
        @JoinColumn(name="parentLastName", referencedColumnName = "lastName"),
        @JoinColumn(name="parentFirstName", referencedColumnName = "firstName")
    })
    public Set<Child> children; //unidirectional
    ...
}

@Entity
public class Child implements Serializable {
    @Id @GeneratedValue
    public Integer id;

    @ManyToOne
    @JoinColumns ({
        @JoinColumn(name="parentCivility", referencedColumnName = "isMale"),
        @JoinColumn(name="parentLastName", referencedColumnName = "lastName"),
        @JoinColumn(name="parentFirstName", referencedColumnName = "firstName")
    })
    public Parent parent; //unidirectional
}

@Embeddable
public class ParentPk implements Serializable {
    String firstName;
    String lastName;
    ...
}