hibernate - 使用 JPA @MapsId 注释共享主键

Question

为了共享 1<>1 关系的主键，我尝试使用 JPA @MapsId 注释但我没有成功。

这是我的 sql 表生成:

CREATE TABLE `myschema`.`table2` (
`id` INT NOT NULL AUTO_INCREMENT,
`coltable2` VARCHAR(45) NULL,
PRIMARY KEY (`id`));

CREATE TABLE `myschema`.`table1` (
`id` INT NOT NULL,
`coltable1` VARCHAR(45) NULL,
PRIMARY KEY (`id`),
CONSTRAINT `fk`
FOREIGN KEY (`id`)
REFERENCES `myschema`.`table2` (`id`)
ON DELETE CASCADE
ON UPDATE CASCADE);

这是我的两个类:

表格1:

@Entity
@Table(name="table1")   
public class Table1 {

@Id 
private int id;

@OneToOne(cascade=CascadeType.ALL, fetch = FetchType.EAGER) 
@JoinColumn(name="id")
@MapsId(value="id") 
private Table2 table2;

....

}   

表 2:

@Entity
@Table(name="table2")   
public class Table2 {

    @Id @GeneratedValue
    private int id;

    @OneToOne(cascade=CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "table2") 
    private Table1 table1;

    ...

}   

因此，当尝试通过这样做来保存时:

Table1 table1 = new Table1();
table1.setColTable1("table1");      

Table2 table2 = new Table2();
table2.setColTable2("table2");      

table1.setTable2(table2);
table2.setTable1(table1);

dao.save(table1);

我收到以下错误:

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails

似乎@MapsId 没有将 id 值从 table2 标识符传播到 table1 标识符。所以约束不受尊重。但我不明白代码有什么问题？

有人可以指出我的错误吗？

Answer 1

我不确定 @MapsId是你想要的。
@PrimaryKeyJoinColumn可能是你需要的:

and it may be used in a OneToOne mapping in which the primary key of the referencing entity is used as a foreign key to the referenced entity.

http://docs.oracle.com/javaee/5/api/javax/persistence/PrimaryKeyJoinColumn.html

http://vard-lokkur.blogspot.co.uk/2011/05/onetoone-with-shared-primary-key.html