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);

        session.save(add3);

        session.save(p1);

        session.save(p2);

        tx.commit();

        HibernateUtil.closeSession();

    }

}

 

七、测试结果

 

1) :正常保存.

        session.save(add1);

        session.save(add2);

        session.save(add3);

        session.save(p1);

        session.save(p2);

Hibernate: insert into PERSON_1nfk (name, age) values (?, ?)

Hibernate: insert into ADDRESS_1nfk (addressdetail) values (?)

Hibernate: insert into ADDRESS_1nfk (addressdetail) values (?)

Hibernate: update ADDRESS_1nfk set personid=? where addressid=?

Hibernate: update ADDRESS_1nfk set personid=? where addressid=?