Hibernate 一对多连接表单向关联

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   原文地址： http://lavasoft.blog.51cto.com/62575/39318

 

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=?

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