Jpa是复合键映射的一部分

Question

我有下表：

@Entity(name = 'STUDENT')
class Student {
@Id    
@Column(name = 'STUDENT_ID')
String studentId
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "id.student")
Set<Disabilities> disabilities = [] 
}

@Entity(name = 'STUDENT_DISABILITY')
class Disability {
@EmbeddedId
DisabilityId id
@Nullable
@Column(name = 'MOD_DT')
LocalDateTime modifiedDate
}
@Embeddable
class DisabilityId implements Serializable {
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = 'STUDENT_ID')
Student student
@Column(name = 'DISABILITY_CD')
String disabilityCode
}

这一切都很好，但我正在尝试将一个新表"Disability_info"表加入"Disability"表。这是Disability_info表：

@Entity
@Table(name = 'DISABILITY_INFO')
class DisabilityInfo {
@Id
@Column(name = 'DISABILITY_CD')
String id
@Column(name = 'DISABILITY_NAME')
String disabilityName
@Column(name = 'DISABILITY_DESC')
String disabilityDesc
}

我遇到的问题是DisabilityInfo的主键是Disability类的复合键的一部分。我想要的只是下面的sql：

SELECT * FROM DISABILITY a INNER JOIN DISABILITY_INFO b on a.DISABILITY_CD = b.DISABILITY_CD

有人能告诉我怎样才能做到这一点吗？

提前谢谢。

Answer 1

我想明白了。需要多对一的关联。我最初的想法是，一种残疾应该有一种描述，因此存在1:1的关系。

然而，在现实中，有多种残疾引用了相同的描述，这意味着这实际上是一种多对一的关系！

@Entity(name = 'STUDENT_DISABILITY')
class Disability {
@EmbeddedId
DisabilityId id
@Nullable
@Column(name = 'MOD_DT')
LocalDateTime modifiedDate

@ManyToOne
@JoinColumn(name = 'DISABILITY_ID, insertable = false, updatable = false)
DisabilityInfo disabilityInfo

}