休眠如何映射設定在我有兩個鍵

Question

我有兩個實體來說甲一個實體，B 其中A是和B之一是許多

答：

@Entity 
    @Table(name = "A") 
    class A...{ 
    @Id 
@Column(name = "A2id",nullable = false) 
private Integer A2id; 

    @Id 
@Column(name = "A1id",nullable = false) 
private Integer A1id; 

    @OneToMany(mappedBy="a") 
private Set<B> Bset; 

    //get's set's and public c'tor 

}

B相類似這樣的

@Entity 
@Table(name = "B") 
public class B implements Serializable{ 

//id's 
@Id 
@Column(name = "B1id", nullable = false) 
private Integer B1id; 
@Id 
@Column(name = "B2id",nullable = false) 
private Integer B2id; 

@ManyToOne 
@JoinColumn(name="B2id",nullable = false) 
private A a; 

//get's set's and public c'tor 
} 

和休眠呼喊對我道：

一個外鍵引用com。 .A from com。 .B的列數錯誤。應該是2

有什麼問題呢？ 請幫我

Answer 1

我發現我如何來解決這個問題：使用

：

@ManyToOne 
@JoinColumns({ 
    @JoinColumn(name = "a1", unique = false, nullable = false, insertable = false, updatable = false), 
    @JoinColumn(name = "a2", unique = false, nullable = false, insertable = false, updatable = false) }) 
private A a;