【hibernate框架】一对一双向外键关联(Annotation实现)

一对一双向外键关联(annotation方法):

一夫(husband)一妻(wife)的一对一双向外键关联

husband和wife实体类：

生成的建表语句：

alter table husband 

        drop 

        foreign key fkaeea401bc6294ced

    alter table wife 

        foreign key fk29233185d75bea

    drop table if exists husband

    drop table if exists wife

    create table husband (

        id integer not null auto_increment,

        name varchar(255),

        wifeid integer,

        primary key (id)

    )

    create table wife (

        husband_id integer,

    alter table husband 

        add index fkaeea401bc6294ced (wifeid), 

        add constraint fkaeea401bc6294ced 

        foreign key (wifeid) 

        references wife (id)

        add index fk29233185d75bea (husband_id), 

        add constraint fk29233185d75bea 

        foreign key (husband_id) 

        references husband (id)

双向关联在数据库中只需一边设置外键就行了,所以wife的husband_id就可以不要

mappedby="wife"告诉hibernate，wife和husband之间是一个1对1的关联，

对方husband类的wife属性已经做映射了,你就不用管我生成的外键的关联了

对方那边是主导，你不用管我这边的设置

这个时候wife建表语句中就没有husband_id属性了

凡是双向关联必设mappedby

所以wife实体类注解写成：

@onetoone(mappedby="wife")

public husband gethusband() {

return husband;

}

生成的表中wife就没有husband_id字段了

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