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 `FK9B93456DA6D6C1F5` (`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 (?, ?)