Hibernate jpa中复合主键上的一对一连接
我有两张桌子。一个是主键,另一个是复合键 表a:Hibernate jpa中复合主键上的一对一连接,hibernate,jpa,Hibernate,Jpa,我有两张桌子。一个是主键,另一个是复合键 表a: @Entity @Table(name = "TableA") public class TableA { @Id @Column(name = "myId") private Long id; @Column(name = "myName") private String name; @Column(name = "myRegion") private String regionNa
@Entity
@Table(name = "TableA")
public class TableA {
@Id
@Column(name = "myId")
private Long id;
@Column(name = "myName")
private String name;
@Column(name = "myRegion")
private String regionName;
}
表B的复合键:
@Embeddable
public class CompositePK implements Serializable {
private static final long serialVersionUID = 1L;
@Column(name = "myId", insertable=false, updatable=false)
private Long myId;
@Column(name = "secondaryId")
private String secondaryId;
}
表B:
@Entity
@Table(name = "TableB")
public class TableB {
@EmbeddedId
private CompositePK compositePK;
@Column(name = "Data")
private String regulationText;
}
现在我想实现这个查询
select * from TableA tableA
inner join TableB tableB
on tableA.myId=tableB.myId
where tableB.myId = 1;
我在TableB中尝试了下面的代码片段(一对一连接)
但它表示无效的列secondaryId。跟这个打了一天。无法使用组合键中的主键联接表。任何帮助都将不胜感激。如果是复合密钥,您需要使用复合密钥对象访问它,如下所示:
@OneToOne(cascade = CascadeType.ALL)
@JoinTable(name = "TableA", inverseJoinColumns = @JoinColumn(name =
"compositePK.myId", referencedColumnName = "myId"))
private TableA tableA;
您应该修改
表B
以使用“派生标识”:
JPA 2.1规范第2.4.1节讨论了派生身份(带有示例)。我已经尝试过了。正在引发异常“无效列secondaryId”。因为TableB包含复合键,所以它正在寻找第二列。但是TableA没有复合键。它只有主键“myId”@ishantgI找到了一个与您的问题类似的解决方案。也许这有助于解决上述问题。不过我还是遇到了同样的异常“Invalid column secondaryId”这是一个有效的解决方案:非常感谢@Brian Vosburgh。我已经试过了解决办法。它完全符合我的要求。太好了!:)如果你有时间,你能接受我的回答吗@用户3016222
@OneToOne(cascade = CascadeType.ALL)
@JoinTable(name = "TableA", inverseJoinColumns = @JoinColumn(name =
"compositePK.myId", referencedColumnName = "myId"))
private TableA tableA;
@Entity
@Table(name = "TableB")
public class TableB {
@EmbeddedId
private CompositePK compositePK;
@ManyToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "myId", referencedColumnName = "myId")
@MapsId("myId") // maps 'myId' attribute of embedded id CompositePK
private TableA tableA;
@Column(name = "Data")
private String regulationText;
}