| 一、模型介紹 |
| 多個人（Person）對應一個地址（Address）。 |
| 二、實體（省略getter、setter方法） |
| public class Personn1fk { |
| PRivate int personid; |
| private String name; |
| private int age; |
| private Addressn1fk addressn1fk; |
| public class Addressn1fk { |
| private int addressid; |
| private String addressdetail; |
| 三、表模型 |
| MySQL> desc address_n1kf; |
| +---------------+--------------+------+-----+---------+----------------+ |
| | Field | Type | Null | Key | Default | Extra | |
| +---------------+--------------+------+-----+---------+----------------+ |
| | addressid | int(11) | NO | PRI | NULL | auto_increment | |
| | addressdetail | varchar(255) | YES | | NULL | | |
| +---------------+--------------+------+-----+---------+----------------+ |
| mysql> desc person_n1kf; |
| +-----------+--------------+------+-----+---------+----------------+ |
| | Field | Type | Null | Key | Default | Extra | |
| +-----------+--------------+------+-----+---------+----------------+ |
| | personid | int(11) | NO | PRI | NULL | auto_increment | |
| | name | varchar(255) | YES | | NULL | | |
| | age | int(11) | YES | | NULL | | |
| | addressId | int(11) | YES | MUL | NULL | | |
| +-----------+--------------+------+-----+---------+----------------+ |
| 四、生成的SQL腳本 |
| CREATE TABLE `address_n1kf` ( |
| `addressid` int(11) NOT NULL auto_increment, |
| `addressdetail` varchar(255) default NULL, |
| PRIMARY KEY (`addressid`) |
| ) ENGINE=InnoDB DEFAULT CHARSET=gbk; |
| DROP TABLE IF EXISTS `person_n1kf`; |
| CREATE TABLE `person_n1kf` ( |
| `personid` int(11) NOT NULL auto_increment, |
| `name` varchar(255) default NULL, |
| `age` int(11) default NULL, |
| `addressId` int(11) default NULL, |
| PRIMARY KEY (`personid`), |
| KEY `FK4571AF54A2A3EE48` (`addressId`), |
| CONSTRAINT `FK4571AF54A2A3EE48` FOREIGN KEY (`addressId`) REFERENCES `address_n1kf` (`addressid`) |
| ) ENGINE=InnoDB DEFAULT CHARSET=gbk; |
| 五、映射方法 |
| <hibernate-mapping> |
| <class name="com.lavasoft.dx._n_1_fk.Personn1fk" table="PERSON_n1fk"> |
| <id name="personid"> |
| <generator class="identity"/> |
| </id> |
| <property name="name"/> |
| <property name="age"/> |
| <!--用來映射關聯PO column是Address在該表中的外鍵列名--> |
| <many-to-one name="addressn1fk" column="addressId"/> |
| </class> |
| </hibernate-mapping> |
| <hibernate-mapping> |
| <class name="com.lavasoft.dx._n_1_fk.Addressn1fk" table="ADDRESS_n1fk"> |
| <id name="addressid"> |
| <generator class="identity"/> |
| </id> |
| <property name="addressdetail"/> |
| </class> |
| </hibernate-mapping> |
| 六、測試方法 |
| public class Test_n1fk { |
| public static void main(String[] args){ |
| Personn1fk p1=new Personn1fk(); |
| Personn1fk p2=new Personn1fk(); |
| p1.setAge(21); |
| p1.setName("p1"); |
| p2.setAge(23); |
| p2.setName("p2"); |
| Addressn1fk add=new Addressn1fk(); |
| add.setAddressdetail("鄭州市經三路"); |
| p1.setAddressn1fk(add); |
| p2.setAddressn1fk(add); |
| session session=HibernateUtil.getCurrentSession(); |
| Transaction tx=session.beginTransaction(); |
| session.save(add); |
| session.save(p1); |
| session.save(p2); |
| tx.commit(); |
| HibernateUtil.closeSession(); |
| } |
| } |
| 七、測試結果 |
| 1) :正常保存. 推薦這么干! |
| session.save(p1); |
| session.save(p2); |
| Hibernate: insert into ADDRESS_n1kf (addressdetail) values (?) |
| Hibernate: insert into PERSON_n1kf (name, age, addressId) values (?, ?, ?) |
| Hibernate: insert into PERSON_n1kf (name, age, addressId) values (?, ?, ?) |
| 2) :正常保存. |
| session.save(p1); |
| session.save(p2); |
| session.save(add); |
| Hibernate: insert into PERSON_n1kf (name, age, addressId) values (?, ?, ?) |
| Hibernate: insert into PERSON_n1kf (name, age, addressId) values (?, ?, ?) |
| Hibernate: insert into ADDRESS_n1kf (addressdetail) values (?) |
| Hibernate: update PERSON_n1kf set name=?, age=?, addressId=? where personid=? |
| Hibernate: update PERSON_n1kf set name=?, age=?, addressId=? where personid=? |
| 3) :正常保存. |
| session.save(add); |
| // session.save(p1); |
| // session.save(p2); |
| Hibernate: insert into ADDRESS_n1kf (addressdetail) values (?) |
| 4) : 發生異常,不能保存. |
| // session.save(add); |
| session.save(p1); |
| session.save(p2); |
| Hibernate: insert into PERSON_n1kf (name, age, addressId) values (?, ?, ?) |
| Hibernate: insert into PERSON_n1kf (name, age, addressId) values (?, ?, ?) |
| Exception in thread "main" org.hibernate.TransientObjectException: com.lavasoft.dx._n_1_fk.Addressn1kf |
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