Hibernate 一对多外键双向关联
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 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 table="ADDRESS_1nfk_sx">
<id name="addressid">
<generator 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 (?, ?)




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