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