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Hibernate 多对一连接表单向关联

2017-02-08 17:45 459 查看
[align=left]Hibernate 多对一连接表单向关联[/align]
 
[align=left] [/align]
[align=left]一、模型介绍[/align]
[align=left] [/align]
[align=left]多个人(Person)对应一个地址(Address)。[/align]
[align=left] [/align]
[align=left]二、实体(省略getter、setter方法)[/align]
[align=left] [/align]
[align=left]public class Personn1tab {[/align]
[align=left]    private int personid;[/align]
[align=left]    private String name;[/align]
[align=left]    private int age;[/align]
[align=left]    private Addressn1tab addressn1tab;[/align]
[align=left] [/align]
[align=left]public class Addressn1tab {[/align]
[align=left]    private int addressid;[/align]
[align=left]    private String addressdetail;[/align]
[align=left] [/align]
[align=left]三、表模型[/align]
[align=left] [/align]
[align=left]mysql> desc address_n1tab;[/align]
[align=left]+---------------+--------------+------+-----+---------+----------------+[/align]
[align=left]| Field         | Type         | Null | Key | Default | Extra          |[/align]
[align=left]+---------------+--------------+------+-----+---------+----------------+[/align]
[align=left]| addressid     | int(11)      | NO   | PRI | NULL    | auto_increment |[/align]
[align=left]| addressdetail | varchar(255) | YES  |     | NULL    |                |[/align]
[align=left]+---------------+--------------+------+-----+---------+----------------+[/align]
[align=left] [/align]
[align=left]mysql> desc join_n1tab;[/align]
[align=left]+------------+---------+------+-----+---------+-------+[/align]
[align=left]| Field      | Type    | Null | Key | Default | Extra |[/align]
[align=left]+------------+---------+------+-----+---------+-------+[/align]
[align=left]| personid   | int(11) | NO   | PRI |         |       |[/align]
[align=left]| addressn1tab | int(11) | YES  | MUL | NULL    |       |[/align]
[align=left]+------------+---------+------+-----+---------+-------+[/align]
[align=left] [/align]
[align=left]mysql> desc person_n1tab;[/align]
[align=left]+----------+--------------+------+-----+---------+----------------+[/align]
[align=left]| Field    | Type         | Null | Key | Default | Extra          |[/align]
[align=left]+----------+--------------+------+-----+---------+----------------+[/align]
[align=left]| personid | int(11)      | NO   | PRI | NULL    | auto_increment |[/align]
[align=left]| name     | varchar(255) | YES  |     | NULL    |                |[/align]
[align=left]| age      | int(11)      | YES  |     | NULL    |                |[/align]
[align=left]+----------+--------------+------+-----+---------+----------------+[/align]
[align=left] [/align]
[align=left]四、生成的SQL脚本[/align]
[align=left] [/align]
[align=left]CREATE TABLE `address_n1tab` ([/align]
[align=left]  `addressid` int(11) NOT NULL auto_increment,[/align]
[align=left]  `addressdetail` varchar(255) default NULL,[/align]
[align=left]  PRIMARY KEY  (`addressid`)[/align]
[align=left]) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=gbk;[/align]
[align=left] [/align]
[align=left]CREATE TABLE `join_n1tab` ([/align]
[align=left]  `personid` int(11) NOT NULL,[/align]
[align=left]  `address11fk` int(11) default NULL,[/align]
[align=left]  PRIMARY KEY  (`personid`),[/align]
[align=left]  KEY `FKAC780AAADAE3A82C` (`personid`),[/align]
[align=left]  KEY `FKAC780AAAC6242A64` (`address11fk`),[/align]
[align=left]  CONSTRAINT `FKAC780AAAC6242A64` FOREIGN KEY (`address11fk`) REFERENCES `address_n1tab` (`addressid`),[/align]
[align=left]  CONSTRAINT `FKAC780AAADAE3A82C` FOREIGN KEY (`personid`) REFERENCES `person_n1tab` (`personid`)[/align]
[align=left]) ENGINE=InnoDB DEFAULT CHARSET=gbk;[/align]
[align=left] [/align]
[align=left]CREATE TABLE `person_n1tab` ([/align]
[align=left]  `personid` int(11) NOT NULL auto_increment,[/align]
[align=left]  `name` varchar(255) default NULL,[/align]
[align=left]  `age` int(11) default NULL,[/align]
[align=left]  PRIMARY KEY  (`personid`)[/align]
[align=left]) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=gbk;[/align]
[align=left] [/align]
[align=left] [/align]
[align=left]五、映射方法[/align]
[align=left] [/align]
[align=left]<hibernate-mapping>[/align]
[align=left]    <class name="com.lavasoft.dx._n_1_tab.Personn1tab" table="PERSON_n1tab">[/align]
[align=left]        <id name="personid">[/align]
[align=left]            <generator class="identity"/>[/align]
[align=left]        </id>[/align]
[align=left]        <property name="name"/>[/align]
[align=left]        <property name="age"/>[/align]
[align=left]        <!--使用join元素显式确定链接表-->[/align]
[align=left]        <join table="join_n1tab">[/align]
[align=left]            <!--映射关联所用的外键-->[/align]
[align=left]            <key column="personid"/>[/align]
[align=left]            <many-to-one name="addressn1tab"/>[/align]
[align=left]        </join>[/align]
[align=left]    </class>[/align]
[align=left]</hibernate-mapping>[/align]
[align=left] [/align]
[align=left]<hibernate-mapping>[/align]
[align=left]    <class name="com.lavasoft.dx._n_1_tab.Addressn1tab" table="ADDRESS_n1tab">[/align]
[align=left]        <id name="addressid">[/align]
[align=left]            <generator class="identity"/>[/align]
[align=left]        </id>[/align]
[align=left]        <property name="addressdetail"/>[/align]
[align=left]    </class>[/align]
[align=left]</hibernate-mapping>[/align]
[align=left] [/align]
[align=left] [/align]
[align=left]六、测试方法[/align]
[align=left] [/align]
[align=left]public class Test_n1tab {[/align]
[align=left]    public static void main(String[] args){[/align]
[align=left]        Personn1tab p1=new Personn1tab();[/align]
[align=left]        Personn1tab p2=new Personn1tab();[/align]
[align=left] [/align]
[align=left]        p1.setAge(21);[/align]
[align=left]        p1.setName("p1");[/align]
[align=left] [/align]
[align=left]        p2.setAge(23);[/align]
[align=left]        p2.setName("p2");[/align]
[align=left] [/align]
[align=left]        Addressn1tab add=new Addressn1tab();[/align]
[align=left]        add.setAddressdetail("郑州市经三路");[/align]
[align=left] [/align]
[align=left]        p1.setAddressn1tab(add);[/align]
[align=left]        p2.setAddressn1tab(add);[/align]
[align=left] [/align]
[align=left]        Session session=HibernateUtil.getCurrentSession();[/align]
[align=left]        Transaction tx=session.beginTransaction();[/align]
[align=left]        session.save(add);[/align]
[align=left]        session.save(p1);[/align]
[align=left]        session.save(p2);[/align]
[align=left]        tx.commit();[/align]
[align=left]        HibernateUtil.closeSession();[/align]
[align=left]    }[/align]
[align=left]}[/align]
[align=left] [/align]
[align=left]七、测试结果[/align]
[align=left] [/align]
[align=left]1) :正常保存. 推荐这么干![/align]
[align=left] [/align]
[align=left]        session.save(p1);[/align]
[align=left]        session.save(p2);[/align]
[align=left] [/align]
[align=left]Hibernate: insert into ADDRESS_n1tab (addressdetail) values (?)[/align]
[align=left]Hibernate: insert into PERSON_n1tab (name, age) values (?, ?)[/align]
[align=left]Hibernate: insert into join_n1tab (address11fk, personid) values (?, ?)[/align]
[align=left]Hibernate: insert into PERSON_n1tab (name, age) values (?, ?)[/align]
[align=left]Hibernate: insert into join_n1tab (address11fk, personid) values (?, ?)[/align]
[align=left] [/align]
[align=left]2) :正常保存.[/align]
[align=left]        session.save(p1);[/align]
[align=left]        session.save(p2);[/align]
[align=left]        session.save(add);[/align]
[align=left] [/align]
[align=left] Hibernate: insert into PERSON_n1tab (name, age) values (?, ?)[/align]
[align=left] Hibernate: insert into join_n1tab (address11fk, personid) values (?, ?)[/align]
[align=left] Hibernate: insert into PERSON_n1tab (name, age) values (?, ?)[/align]
[align=left] Hibernate: insert into join_n1tab (address11fk, personid) values (?, ?)[/align]
[align=left] [/align]
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