| 這種情況很少見，但Hibernate同樣允許采用連接表關聯1-1.有連接表的1-1同樣只需要將N-1的many-to-one元素增加unique="true"屬性即可。 |
| 一、模型介紹 |
| 一個人（Person）對應一個地址（Address）。 |
| 二、實體（省略getter、setter方法） |
| public class Person11tab { |
| PRivate int personid; |
| private String name; |
| private int age; |
| private Address11tab address11tab; |
| public class Address11tab { |
| private int addressid; |
| private String addressdetail; |
| 三、表模型 |
| MySQL> desc address_11tab; |
| +---------------+--------------+------+-----+---------+----------------+ |
| | Field | Type | Null | Key | Default | Extra | |
| +---------------+--------------+------+-----+---------+----------------+ |
| | addressid | int(11) | NO | PRI | NULL | auto_increment | |
| | addressdetail | varchar(255) | YES | | NULL | | |
| +---------------+--------------+------+-----+---------+----------------+ |
| mysql> desc join_11tab; |
| +--------------+---------+------+-----+---------+-------+ |
| | Field | Type | Null | Key | Default | Extra | |
| +--------------+---------+------+-----+---------+-------+ |
| | personid | int(11) | NO | PRI | | | |
| | address11tab | int(11) | YES | UNI | NULL | | |
| +--------------+---------+------+-----+---------+-------+ |
| mysql> desc person_11tab; |
| +----------+--------------+------+-----+---------+----------------+ |
| | Field | Type | Null | Key | Default | Extra | |
| +----------+--------------+------+-----+---------+----------------+ |
| | personid | int(11) | NO | PRI | NULL | auto_increment | |
| | name | varchar(255) | YES | | NULL | | |
| | age | int(11) | YES | | NULL | | |
| +----------+--------------+------+-----+---------+----------------+ |
| 四、生成的SQL腳本 |
| /* Formatted on 2007/08/20 16:52 (QP5 v5.50) */ |
| CREATE TABLE `join_11tab` ( |
| `personid` int(11) NOT NULL, |
| `address11tab` int(11) default NULL, |
| PRIMARY KEY (`personid`), |
| UNIQUE KEY `address11tab` (`address11tab`), |
| KEY `FK6B44BE20C4CC3D33` (`address11tab`), |
| KEY `FK6B44BE209049BB1F` (`personid`), |
| CONSTRAINT `FK6B44BE209049BB1F` FOREIGN KEY (`personid`) REFERENCES `person_11tab` (`personid`), |
| CONSTRAINT `FK6B44BE20C4CC3D33` FOREIGN KEY (`address11tab`) REFERENCES `address_11tab` (`addressid`) |
| ) ENGINE=InnoDB DEFAULT CHARSET=gbk; |
| /* Formatted on 2007/08/20 16:53 (QP5 v5.50) */ |
| CREATE TABLE `address_11tab` ( |
| `addressid` int(11) NOT NULL auto_increment, |
| `addressdetail` varchar(255) default NULL, |
| PRIMARY KEY (`addressid`) |
| ) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=gbk; |
| /* Formatted on 2007/08/20 16:53 (QP5 v5.50) */ |
| CREATE TABLE `person_11tab` ( |
| `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：在Person中添加Address屬性，映射配置為： |
| <!--使用join元素顯式確定鏈接表--> |
| <join table="join_11tab"> |
| <key column="personid"/> |
| <!--映射1-1關聯屬性，其中unique=“true”屬性確定為“1-1”--> |
| <many-to-one name="address11tab" unique="true"/> |
| </join> |
| <hibernate-mapping> |
| <class name="com.lavasoft.dx._1_1_tab.Person11tab" table="PERSON_11tab"> |
| <id name="personid"> |
| <generator class="identity"/> |
| </id> |
| <property name="name"/> |
| <property name="age"/> |
| <!--使用join元素顯式確定鏈接表--> |
| <join table="join_11tab"> |
| <key column="personid"/> |
| <!--映射1-1關聯屬性，其中unique=“true”屬性確定為“1-1”--> |
| <many-to-one name="address11tab" unique="true"/> |
| </join> |
| </class> |
| </hibernate-mapping> |
| <hibernate-mapping> |
| <class name="com.lavasoft.dx._1_1_tab.Address11tab" table="ADDRESS_11tab"> |
| <id name="addressid"> |
| <generator class="identity"/> |
| </id> |
| <property name="addressdetail"/> |
| </class> |
| </hibernate-mapping> |
| 六、測試方法 |
| public class Test_11tab { |
| public static void main(String[] args){ |
| Person11tab p1=new Person11tab(); |
| p1.setAge(21); |
| p1.setName("p1"); |
| Address11tab add1=new Address11tab(); |
| add1.setAddressdetail("鄭州市經三路"); |
| p1.setAddress11tab(add1); |
| session session= HibernateUtil.getCurrentSession(); |
| Transaction tx=session.beginTransaction(); |
| session.save(add1); |
| session.save(p1); |
| tx.commit(); |
| HibernateUtil.closeSession(); |
| } |
| } |
| 七、測試結果 |
| 1) :正常保存. 推薦這么干! |
| session.save(add1); |
| session.save(p1); |
| Hibernate: insert into ADDRESS_11tab (addressdetail) values (?) |
| Hibernate: insert into PERSON_11tab (name, age) values (?, ?) |
| Hibernate: insert into join_11tab (address11tab, personid) values (?, ?) |
| 2) :正常保存. |
| session.save(p1); |
| session.save(add1); |
| Hibernate: insert into PERSON_11tab (name, age) values (?, ?) |
| Hibernate: insert into join_11tab (address11tab, personid) values (?, ?) |
| Hibernate: insert into ADDRESS_11tab (addressdetail) values (?) |
| Hibernate: update join_11tab set address11tab=? where personid=? |
| 3) :正常保存. |
| // session.save(p1); |
| session.save(add1); |
| Hibernate: insert into ADDRESS_11tab (addressdetail) values (?) |
| 4) : 發生異常,不能保存. |
| session.save(p1); |
| // session.save(add1); |
| Hibernate: insert into PERSON_11tab (name, age) values (?, ?) |
| Hibernate: insert into join_11tab (address11tab, personid) values (?, ?) |
| Exception in thread "main" org.hibernate.TransientObjectException: com.lavasoft.dx._1_1_tab.Address11tab |
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