Hibernate 一对多连接表单向关联

Hibernate  一对多连接表单向关联

 

 

一、模型介绍

 

一个人（Person ）对应多个地址（Address ），比如家庭地址、公司地址。

 

二、实体（省略getter 、setter 方法）

 

public class Person1ntab {

     private int personid;

     private String name;

     private int age;

     private Set addresses=new HashSet();

 

public class Address1nfk implements Serializable {

     private int addressid;

     private String addressdetail;

 

三、表模型

 

mysql> desc join_1ntab;

+-----------+---------+------+-----+---------+-------+

| Field      | Type     | Null | Key | Default | Extra |

+-----------+---------+------+-----+---------+-------+

| personid   | int(11) | NO    | PRI |          |        |

| addressid | int(11) | NO    | PRI |          |        |

+-----------+---------+------+-----+---------+-------+

 

mysql> desc person_1ntab;

+----------+--------------+------+-----+---------+----------------+

| Field     | Type          | Null | Key | Default | Extra           |

+----------+--------------+------+-----+---------+----------------+

| personid | int(11)        | NO    | PRI | NULL     | auto_increment |

| name      | varchar(255) | YES   |      | NULL     |                 |

| age       | int(11)       | YES   |      | NULL     |                 |

+----------+--------------+------+-----+---------+----------------+

 

mysql> desc address_1ntab;

+---------------+--------------+------+-----+---------+----------------+

| Field          | Type          | Null | Key | Default | Extra           |

+---------------+--------------+------+-----+---------+----------------+

| addressid      | int(11)       | NO    | PRI | NULL     | auto_increment |

| addressdetail | varchar(255) | YES   |      | NULL     |                 |

+---------------+--------------+------+-----+---------+----------------+

 

四、生成的SQL 脚本

 

/* Formatted on 2007/08/21 10:58 (QP5 v5.50) */

CREATE TABLE `address_1ntab` (

   `addressid` int(11) NOT NULL auto_increment,

   `addressdetail` varchar(255) default NULL,

   PRIMARY KEY   (`addressid`)

) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=gbk;

 

/* Formatted on 2007/08/21 10:58 (QP5 v5.50) */

CREATE TABLE `join_1ntab` (

   `personid` int(11) NOT NULL,

   `addressid` int(11) NOT NULL,

   PRIMARY KEY   (`personid`,`addressid`),

   UNIQUE KEY `addressid` (`addressid`),

   KEY `FK6B6078C3C8DF5BFF` (`personid`),

   KEY `FK6B6078C3C2B11347` (`addressid`),

   CONSTRAINT `FK6B6078C3C2B11347` FOREIGN KEY (`addressid`) REFERENCES `address_1ntab` (`addressid`),

   CONSTRAINT `FK6B6078C3C8DF5BFF` FOREIGN KEY (`personid`) REFERENCES `person_1ntab` (`personid`)

) ENGINE=InnoDB DEFAULT CHARSET=gbk;

 

/* Formatted on 2007/08/21 10:58 (QP5 v5.50) */

CREATE TABLE `person_1ntab` (

   `personid` int(11) NOT NULL auto_increment,

   `name` varchar(255) default NULL,

   `age` int(11) default NULL,

   PRIMARY KEY   (`personid`)

) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=gbk;

 

 

五、映射方法

 

<hibernate-mapping>

     <class name="com.lavasoft.dx._1_n_tab.Person1ntab" table="PERSON_1ntab">

         <id name="personid">

             <generator class="identity"/>

         </id>

         <property name="name"/>

         <property name="age"/>

         <!-- 映射集合属性，join_1ntab 是连接表表名-->

         <set name="addresses"

              table="join_1ntab"

                 >

             <!-- “column="personid" ”确定PERSON_1ntab 表关联到连接表的外键列名-->

             <key column="personid"/>

             <!-- “column="addressid" ”关联PERSON_1ntab 表的Address1ntab 对象的id 在连接表中的列名-->

             <!-- “unique="true" 表示1-N ，Person1ntab 是1 ，Address1ntab 是多”-->

             <many-to-many

                     column="addressid"

                     unique="true"

                      class="com.lavasoft.dx._1_n_tab.Address1ntab"/>

         </set>

     </class>

</hibernate-mapping>

 

<hibernate-mapping>

     <class name="com.lavasoft.dx._1_n_tab.Address1ntab" table="ADDRESS_1ntab">

         <id name="addressid">

              <generator class="identity"/>

         </id>

         <property name="addressdetail"/>

     </class>

</hibernate-mapping>

 

 

六、测试方法

 

public class Test_1ntab {

     public static void main(String[] args){

         Address1ntab add1=new Address1ntab();

         Address1ntab add2=new Address1ntab();

         Address1ntab add3=new Address1ntab();

         Person1ntab p1=new Person1ntab();

         Person1ntab p2=new Person1ntab();

 

         add1.setAddressdetail(" 郑州市经三路");

         add2.setAddressdetail(" 合肥市宿州路");

         add3.setAddressdetail(" 北京市长安路");

         p1.setName("wang");

         p1.setAge(30);

         p2.setName("lee");

         p2.setAge(50);

 

         p1.getAddresses().add(add1);

         p1.getAddresses().add(add2);

         //p2.getAddresses().add(add2);

         p2.getAddresses().add(add3);

 

         Session session= HibernateUtil.getCurrentSession();

         Transaction tx=session.beginTransaction();

         session.save(add1);

         session.save(add2);