OneToMany和复杂的PK

Question

我有一对多映射的问题。
两张表问题（PK（id），文本）和答案（PK（id，questionId），文本）
在我的应用程序中，我以只读模式使用这些表。
我想这个表

@Entity 
@Table(name = "QUESTIONS") 
public class Question { 
    @Id 
    @Column(name = "QUESTIONID") 
    private long questionId; 
    @Column(name = "QUESTIONTEXT") 
    private String questionText; 
    @OneToMany(mappedBy = "question", fetch = FetchType.EAGER) 
    private List<Answer> answers;   
} 

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

    @EmbeddedId 
    private AnswerPK AnswerPK; 
    @Column(name = "ANSWERTEXT") 
    private String answerText; 
    @ManyToOne 
    @JoinColumn(name = "QUESTIONID", insertable = false, updatable = false) 
    private Question question; 
} 

@Embeddable 
public class AnswerPK implements Serializable { 
    @Column(name = "QUESTIONID") 
    private long questionId; 
    @Column(name = "ANSWERID") 
    private int answerId; 
} 

但是当我使用@JoinColumn将建立外键之间的关系定义。
，当我尝试填写表格，我得到异常

java.sql.SQLIntegrityConstraintViolationException: ORA-02292: integrity constraint (ZODI.FK_ANSWERS_QUESTIONID) violated - child record found 

Answer 1

尝试把插入/更新=假在EmbeddedId，而不是JoinColumn。

另外考虑不使用EmbeddedId，而是使用IdClass，那么你只需要用@Id注解answerId和问题。或者甚至更好，从主键中移除questionId并确保answerId是唯一的（例如使其成为生成的ID）。

见， http://en.wikibooks.org/wiki/Java_Persistence/Identity_and_Sequencing#Primary_Keys_through_OneToOne_and_ManyToOne_Relationships