JPA注解实现one-to-one的主键关联映射

作者：xyzroundo

 

假设两个数据表的主-从表：

 

Tb_Account（.... , primary key (ac_id)），Tb_ContactInfo(..., primary key (ci_id))

 

alter table Tb_ContactInfo add constraint FKABAF989DFBC1A028 foreign key (ci_id) references Tb_Account

 

实体配置如下：

 

@Entity
@Table(name = "Tb_Account")

public class Account{

     @Id
    @Column(name = "ac_id", columnDefinition = "INT")
    public Integer id;

　......

    @OneToOne(mappedBy="account")
    private ContactInfo contact;

   .....

}

 

 

@Entity
@Table(name = "Tb_ContactInfo")
public class ContactInfo {

    @Id
    @Column(name = "ci_id", columnDefinition = "INT")
    private Integer id;

　 ......

    @OneToOne(optional=false)
    @PrimaryKeyJoinColumn
    private Account account;

    ......

 

}

 

注：optional=false很重要，它指定关联属性不能为空。只要设为false，生成的数据表的从表(Tb_ContactInfo)才会有外键约束