Hibernate 一对一主键双向关联

Hibernate 一对一主键双向关联

 

一对一主键映射在一对一映射中还算是最为常用的。

 

一、模型

 

一个人Person 对应一个地址Address。

 

二、数据模型和对象模型图

 

 

导出建表SQL如下：

 

/*==============================================================*/
/* DBMS name:            MySQL 5.0                                                                        */
/* Created on:         2008-12-8 23:05:32                                                     */
/*==============================================================*/


drop table if exists address;

drop table if exists person;

/*==============================================================*/
/* Table: address                                                                                             */
/*==============================================================*/
create table address
(
     id                                     bigint not null comment 'ID',
     detail                             varchar(120) not null comment '详细地址',
     primary key (id)
)
type = InnoDB;

alter table address comment '地址';

/*==============================================================*/
/* Table: person                                                                                                */
/*==============================================================*/
create table person
(
     id                                     bigint not null auto_increment comment 'ID',
     name                                 varchar(24) not null comment '姓名',
     primary key (id)
)
type = InnoDB;

alter table person comment '人';

alter table address add constraint FK_Reference_2 foreign key (id)
             references person (id) on delete restrict on update restrict;

 

三、对象模型代码

 

public class Person implements java.io.Serializable {

   private Long id;
   private String name;
   private Address address;

 

public class Address implements java.io.Serializable {
   private Long id;
   private Person person;
   private String detail;

 

四、映射代码

<? xml version ="1.0" encoding ="utf-8" ?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

< hibernate-mapping >
   < class name ="entity.Person" table ="person" >
     < id name ="id" type ="java.lang.Long" >
       < column name ="id" />
       < generator class ="identity" />
     </ id >
     < property name ="name" type ="java.lang.String" >
       < column name ="name" length ="24" not-null ="true" >
         < comment >姓名 </ comment >
       </ column >
     </ property >
    <!-- cascade="all"：在保存person对象的时候，级联保存person对象关联的address对象    -->
     < one-to-one name ="address" cascade ="all" />
   </ class >
</ hibernate-mapping >

 

<? xml version ="1.0" encoding ="utf-8" ?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

< hibernate-mapping >
   < class name ="entity.Address" table ="address" catalog ="mydb" >
     < id name ="id" type ="java.lang.Long" >
       < column name ="id" />
      <!-- class="foreign": 一对一主键映射中，使用另外一个相关联的对象的标识符 -->
       < generator class ="foreign" >
         < param name ="property" >person </ param >
       </ generator >
     </ id >
     < property name ="detail" type ="java.lang.String" >
       < column name ="detail" length ="120" not-null ="true" >
         < comment >详细地址 </ comment >
       </ column >
     </ property >
    <!-- 表示在address表存在一个外键约束，外键参考相关联的表person -->
     < one-to-one name ="person" constrained ="true" />
   </ class >
</ hibernate-mapping >

 

五、Hibernate配置

<? xml version ='1.0' encoding ='UTF-8' ?>
<!DOCTYPE hibernate-configuration PUBLIC
                    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
                    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                                     -->
< hibernate-configuration >

< session-factory >
   < property name ="connection.username" >root </ property >
   < property name ="connection.url" >
    jdbc:mysql://localhost:3306/mydb
   </ property >
   < property name ="dialect" >
    org.hibernate.dialect.MySQLDialect
   </ property >
   < property name ="connection.password" >xiaohui </ property >
   < property name ="connection.driver_class" >
    com.mysql.jdbc.Driver
   </ property >
   < property name ="show_sql" >true </ property >
   < property name ="format_sql" >true </ property >
   < mapping resource ="entity/Person.hbm.xml" />
   < mapping resource ="entity/Address.hbm.xml" />

</ session-factory >

</ hibernate-configuration >

 

测试很简单就不写了。

 

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