Hibernate 一对多外键双向关联

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Hibernate 一对多外键双向关联

一、模型介绍

一个人（Person）对应多个地址（Address）。

二、实体（省略getter、setter方法）

public class Person1nfk_sx implements Serializable {

private int personid;

private String name;

private int age;

private Set addresses=new HashSet();

public class Address1nfk_sx implements Serializable {

private int addressid;

private String addressdetail;

private Person1nfk_sx person1nfkSx;

三、表模型

mysql> desc person_1nfk_sx;

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

| 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_1nfk_sx;

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

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

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

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

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

| personid      | int(11)      | NO   | MUL |         |                |

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

四、生成的SQL脚本

/* Formatted on 2007/08/22 17:42 (QP5 v5.50) */

CREATE TABLE `address_1nfk` (

`addressid` int(11) NOT NULL auto_increment,

`addressdetail` varchar(255) default NULL,

`personid` int(11) default NULL,

PRIMARY KEY  (`addressid`),

KEY `FK9B93456DA6D<?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />6C1F5` (`personid`),

CONSTRAINT `FK9B93456DA6D6C1F5` FOREIGN KEY (`personid`) REFERENCES `person_1nfk` (`personid`)

) ENGINE=InnoDB DEFAULT CHARSET=gbk;

/* Formatted on 2007/08/22 17:42 (QP5 v5.50) */

CREATE TABLE `person_1nfk` (

`personid` int(11) NOT NULL auto_increment,

`name` varchar(255) default NULL,

`age` int(11) default NULL,

PRIMARY KEY  (`personid`)

) ENGINE=InnoDB DEFAULT CHARSET=gbk;

五、映射方法

<hibernate-mapping>

<class name="com.lavasoft.sx._1_n_fk.Person1nfk_sx" table="PERSON_1nfk_sx">

<id name="personid">

<generator class="identity"/>

</id>

<property name="name"/>

<property name="age"/>

<!--映射集合属性，关联到持久化类-->

<set name="addresses" inverse="true" cascade="all">

<!--column用于指定外键列名-->

<key column="personid" not-null="true"/>

<!--映射关联类-->

<one-to-many class="com.lavasoft.sx._1_n_fk.Address1nfk_sx"/>

</set>

</class>

</hibernate-mapping>

<hibernate-mapping>

<class name="com.lavasoft.sx._1_n_fk.Address1nfk_sx" table="ADDRESS_1nfk_sx">

<id name="addressid">

<generator class="identity"/>

</id>

<property name="addressdetail"/>

<!--映射关联属性，column属性指定外键列名-->

<many-to-one name="person1nfk"

class="com.lavasoft.sx._1_n_fk.Person1nfk_sx"

fetch="select"

cascade="save-update">

<column name="personid" not-null="true"/>

</many-to-one>

</class>

</hibernate-mapping>

六、测试方法

public class Test_1nfk_sx {

public static void main(String[] args){

Address1nfk_sx add1=new Address1nfk_sx();

Address1nfk_sx add2=new Address1nfk_sx();

Person1nfk_sx p=new Person1nfk_sx();

add1.setAddressdetail("郑州市经三路");

add2.setAddressdetail("合肥市宿州路");

p.setName("wang");

p.setAge(30);

p.getAddresses().add(add1);

p.getAddresses().add(add2);

add1.setPerson1nfk(p);

add2.setPerson1nfk(p);

Session session= HibernateUtil.getCurrentSession();

Transaction tx=session.beginTransaction();

session.save(p);

session.saveOrUpdate(add1);

session.saveOrUpdate(add2);

tx.commit();

HibernateUtil.closeSession();

}

}

七、测试结果

1) :正常保存.

session.save(p);

session.saveOrUpdate(add1);

session.saveOrUpdate(add2);

Hibernate: insert into PERSON_1nfk_sx (name, age) values (?, ?)

Hibernate: insert into ADDRESS_1nfk_sx (addressdetail, personid) values (?, ?)

Hibernate: insert into ADDRESS_1nfk_sx (addressdetail, personid) values (?, ?)