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

 Person ：

public class Person implements java.io.Serializable { 
 
  private Long id; 
  private String name; 
  private Address address;

 

 Address ：

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

 

 

四、映射代码

Person：

<?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>

 

 Address：

<?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。

 

来源于：

http://lavasoft.blog.51cto.com/62575/39333