使用Hibernate获取多列主键

Question

假设我有一个看起来像这样的类:

public class MyClass {
  @Id
  @Column(name = "ID")
  private long Id;
}

我可以使用hibernate会话对类进行get或load,如下所示:

MyClass a = (MyClass)session.get(MyClass.class, new Long(100));

但是,假设我有一个以多列为主键的类:

public MyJoinClass implements Serializable {
  private static final long serialVersionUID = -5L;
  @Id
  @Column(name = "ID")
  private long id;

  @Id
  @Column(name = "EMAIL_ADDRESS_ID")
  private long emailAddressId;
}

是否可以使用get或load这样的类？

Answer 1

尝试使用和@IdClass或@EmbeddedId

public MyJoinClass implements Serializable {
  private static final long serialVersionUID = -5L;

  @EmbeddedId
  private MyJoinClassKey key;
}

public MyJoinClassKey implements Serializable{

  @Column(name = "ID")
  private long id;

  @Column(name = "EMAIL_ADDRESS_ID")
  private long emailAddressId;
}

然后用

MyJoinClass a = (MyJoinClass )session.get(MyJoinClass .class, new MyJoinClassKey (1, "email"));

看看这个问题,这是广泛的解释.基本上,hibernate有复合键的机制.