Hibernate关联之一对多连接表单向关联

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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 Address1ntab implements Serializable {

private int addressid;

private String addressdetail;

三、表模型

mysql> desc join_1ntab;

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

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

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

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

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

mysql> desc person_1ntab;

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

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

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

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

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

mysql> desc address_1ntab;

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

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

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

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

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

OneToManyTabPerson.hbm.xml

<hibernate-mapping>     <class name="com.bean.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" inverse="true" 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 class="com.bean.Address1ntab" column="addressid" unique="true" />         </set>     </class> </hibernate-mapping>

OneToManyTabAddress.hbm.xml

<hibernate-mapping>     <class name="com.bean.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("天津市");         add2.setAddressdetail("大连市");         add3.setAddressdetail("哈尔滨市");         p1.setName("liu");        p1.setAge(30);        p2.setName("lee");        p2.setAge(29);        p1.getAddresses().add(add1);        p1.getAddresses().add(add3);         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();     }}

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