Hibernate 一對多外鍵雙向關聯 |
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一、模型介紹 |
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一個人（Person）對應多個地址（Address）。 |
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二、實體（省略getter、setter方法） |
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public class Person1nfk_sx implements Serializable { |
private int personid; |
private String name; |
private int age; |
private Set addresses=new HashSet(); |
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public class Address1nfk_sx implements Serializable { |
private int addressid; |
private String addressdetail; |
private Person1nfk_sx person1nfkSx; |
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三、表模型 |
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mysql> desc person_1nfk_sx; |
+----------+--------------+------+-----+---------+----------------+ |
| Field | Type | Null | Key | Default | Extra | |
+----------+--------------+------+-----+---------+----------------+ |
| personid | int(11) | NO | PRI | NULL | auto_increment | |
| name | varchar(255) | YES | | NULL | | |
| age | int(11) | YES | | NULL | | |
+----------+--------------+------+-----+---------+----------------+ |
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mysql> desc address_1nfk_sx; |
+---------------+--------------+------+-----+---------+----------------+ |
| Field | Type | Null | Key | Default | Extra | |
+---------------+--------------+------+-----+---------+----------------+ |
| addressid | int(11) | NO | PRI | NULL | auto_increment | |
| addressdetail | varchar(255) | YES | | NULL | | |
| personid | int(11) | NO | MUL | | | |
+---------------+--------------+------+-----+---------+----------------+ |
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四、生成的SQL腳本 |
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/* Formatted on 2007/08/22 17:42 (QP5 v5.50) */ |
CREATE TABLE `address_1nfk` ( |
`addressid` int(11) NOT NULL auto_increment, |
`addressdetail` varchar(255) default NULL, |
`personid` int(11) default NULL, |
PRIMARY KEY (`addressid`), |
KEY `FK9B93456DA6D6C1F5` (`personid`), |
CONSTRAINT `FK9B93456DA6D6C1F5` FOREIGN KEY (`personid`) REFERENCES `person_1nfk` (`personid`) |
) ENGINE=InnoDB DEFAULT CHARSET=gbk; |
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/* Formatted on 2007/08/22 17:42 (QP5 v5.50) */ |
CREATE TABLE `person_1nfk` ( |
`personid` int(11) NOT NULL auto_increment, |
`name` varchar(255) default NULL, |
`age` int(11) default NULL, |
PRIMARY KEY (`personid`) |
) ENGINE=InnoDB DEFAULT CHARSET=gbk; |
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五、映射方法 |
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<hibernate-mapping> |
<class name="com.lavasoft.sx._1_n_fk.Person1nfk_sx" table="PERSON_1nfk_sx"> |
<id name="personid"> |
<generator class="identity"/> |
</id> |
<property name="name"/> |
<property name="age"/> |
<!--映射集合屬性，關聯到持久化類--> |
<set name="addresses" inverse="true" cascade="all"> |
<!--column用于指定外鍵列名--> |
<key column="personid" not-null="true"/> |
<!--映射關聯類--> |
<one-to-many class="com.lavasoft.sx._1_n_fk.Address1nfk_sx"/> |
</set> |
</class> |
</hibernate-mapping> |
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<hibernate-mapping> |
<class name="com.lavasoft.sx._1_n_fk.Address1nfk_sx" table="ADDRESS_1nfk_sx"> |
<id name="addressid"> |
<generator class="identity"/> |
</id> |
<property name="addressdetail"/> |
<!--映射關聯屬性，column屬性指定外鍵列名--> |
<many-to-one name="person1nfk" |
class="com.lavasoft.sx._1_n_fk.Person1nfk_sx" |
fetch="select" |
cascade="save-update"> |
<column name="personid" not-null="true"/> |
</many-to-one> |
</class> |
</hibernate-mapping> |
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六、測試方法 |
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public class Test_1nfk_sx { |
public static void main(String[] args){ |
Address1nfk_sx add1=new Address1nfk_sx(); |
Address1nfk_sx add2=new Address1nfk_sx(); |
Person1nfk_sx p=new Person1nfk_sx(); |
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add1.setAddressdetail("鄭州市經三路"); |
add2.setAddressdetail("合肥市宿州路"); |
p.setName("wang"); |
p.setAge(30); |
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p.getAddresses().add(add1); |
p.getAddresses().add(add2); |
add1.setPerson1nfk(p); |
add2.setPerson1nfk(p); |
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Session session= HibernateUtil.getCurrentSession(); |
Transaction tx=session.beginTransaction(); |
session.save(p); |
session.saveOrUpdate(add1); |
session.saveOrUpdate(add2); |
tx.commit(); |
HibernateUtil.closeSession(); |
} |
} |
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七、測試結果 |
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1) :正常保存. |
session.save(p); |
session.saveOrUpdate(add1); |
session.saveOrUpdate(add2); |
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Hibernate: insert into PERSON_1nfk_sx (name, age) values (?, ?) |
Hibernate: insert into ADDRESS_1nfk_sx (addressdetail, personid) values (?, ?) |
Hibernate: insert into ADDRESS_1nfk_sx (addressdetail, personid) values (?, ?) |