今天练习了一下hibernate的一对一关联（主键关联），其实就是抄了一遍书上的例子。
用的例子是《深入浅出hibernate》的一对一关联例子，中国公民与护照形成的一对一主键关联。
代码如下：
数据库使用的MSSQLServer2000，我已经导出SQL语句如下：
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_TPassport_TUser]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1)
ALTER TABLE [dbo].[TPassport] DROP CONSTRAINT FK_TPassport_TUser
GO
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[TPassport]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[TPassport]
GO
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[TUser]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[TUser]
GO
CREATE TABLE [dbo].[TPassport] (
[id] [int] NOT NULL ,
[serial] [varchar] (50) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[expiry] [int] NOT NULL
) ON [PRIMARY]
GO
CREATE TABLE [dbo].[TUser] (
[id] [int] IDENTITY (1, 1) NOT NULL ,
[name] [varchar] (50) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[age] [int] NOT NULL ,
[gender] [varchar] (50) COLLATE Chinese_PRC_CI_AS NOT NULL
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[TPassport] WITH NOCHECK ADD
CONSTRAINT [PK_TPassport] PRIMARY KEY CLUSTERED
(
[id]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[TUser] WITH NOCHECK ADD
CONSTRAINT [PK_TUser] PRIMARY KEY CLUSTERED
(
[id]
) ON [PRIMARY]
GO
CREATE INDEX [F_TUser] ON [dbo].[TUser]([id]) ON [PRIMARY]
GO
CREATE INDEX [FK_TUser] ON [dbo].[TUser]([id]) ON [PRIMARY]
GO
ALTER TABLE [dbo].[TPassport] ADD
CONSTRAINT [FK_TPassport_TUser] FOREIGN KEY
(
[id]
) REFERENCES [dbo].[TUser] (
[id]
)
GO
复制以上代码到查询分析器，即可生成相应数据库。呵呵
然后就是POJO了，有两个，分别是：
eg.one2one.bean.TPassport；
package eg.one2one.bean;
import java.io.Serializable;
public class TPassport implements Serializable {
private static final long serialVersionUID = 1L;
private Integer id;
private String serial;
private Integer expiry;
private TUser user;
/*
* 省略的getter()和setter()
**/
}
eg.one2one.bean.TUser；
package eg.one2one.bean;
import java.io.Serializable;
public class TUser implements Serializable {
private static final long serialVersionUID = 1L;
private Integer id;
private String name;
private String gender;
private Integer age;
private TPassport passport;
/*
* 省略的getter()和setter()
**/
}
接下来就应该书写mapping文件了。
TPassport.hbm.xml
<hibernate-mapping>
<class name="eg.one2one.bean.TPassport" table="TPassport">
<id name="id" type="java.lang.Integer" column="id">
<generator class="foreign">
<param name="property">user</param>
</generator>
</id>
<one-to-one name="user"
class="eg.one2one.bean.TUser"
constrained="true"></one-to-one>
<property name="serial" type="java.lang.String" column="serial"></property>
<property name="expiry" type="java.lang.Integer" column="expiry"></property>
</class>
</hibernate-mapping>
TUser.hbm.xml
<hibernate-mapping>
<class name="eg.one2one.bean.TUser" table="TUser">
<id name="id" type="java.lang.Integer" column="id">
<generator class="native">
<param name="property">passport</param>
</generator>
</id>
<property name="name" type="java.lang.String" column="name"></property>
<property name="gender" type="java.lang.String" column="gender"></property>
<property name="age" type="java.lang.Integer" column="age"></property>
<one-to-one name="passport"
class="eg.one2one.bean.TPassport"
cascade="all"
outer-join="true"></one-to-one>
</class>
</hibernate-mapping>
哇，已经贴了这么多了，还没完呢。配置文件内容如下：
<session-factory>
<property name="connection.username">yourusername</property>
<property name="connection.url">
jdbc:microsoft:sqlserver://127.0.0.1:1433;dataBaseName=Test
</property>
<property name="dialect">
org.hibernate.dialect.SQLServerDialect
</property>
<property name="myeclipse.connection.profile">One2OneTest</property>
<property name="connection.password">yourpassword</property>
<property name="connection.driver_class">
com.microsoft.jdbc.sqlserver.SQLServerDriver
</property>
<property name="show_sql">true</property>
<mapping resource="eg/one2one/bean/TUser.hbm.xml" />
<mapping resource="eg/one2one/bean/TPassport.hbm.xml" />
</session-factory>
Ok，好了。写了这么多代码，能不能执行，测试一下吧。
package eg.one2one.util;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static SessionFactory sessionFactory;
private HibernateUtil() {
}
public static SessionFactory getSessionFactory() {
if (sessionFactory == null) {
Configuration config = new Configuration();
config.configure();
sessionFactory = config.buildSessionFactory();
}
return sessionFactory;
}
}
测试类：
package eg.test;
import java.util.Iterator;
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import eg.one2one.bean.TPassport;
import eg.one2one.bean.TUser;
import eg.one2one.util.HibernateUtil;
public class One2OneTest {
public static void main(String[] args) {
SessionFactory sessionFactory =
HibernateUtil.getSessionFactory();
Session session = sessionFactory.openSession();
/* TUser user = (TUser) session.load(TUser.class, new Integer(1));
Transaction trans = null;
try{
trans = session.beginTransaction();
session.delete(user);
trans.commit();
}catch(HibernateException e){
e.printStackTrace();
if(trans != null)
trans.rollback();
}*/
/* TUser user = (TUser) session.load(TUser.class, new Integer(2));
user.setName("beauty");
user.setAge(new Integer(20));
user.setGender("femal");
user.getPassport().setExpiry(new Integer(100));
user.getPassport().setSerial("Australian");
Transaction trans = null;
try{
trans = session.beginTransaction();
session.save(user);
trans.commit();
}catch(HibernateException e){
e.printStackTrace();
if(trans != null)
trans.rollback();
}*/
/* Query query = session.createQuery("from TUser");
List list = query.list();
Iterator it = list.iterator();
while(it.hasNext()){
TUser user = (TUser)it.next();
System.out.print(user.getId() + "\t");
System.out.print(user.getName() + "\t");
System.out.print(user.getGender() + "\t");
System.out.print(user.getAge() + "\t");
System.out.print(user.getPassport().getSerial() + "\t");
System.out.println(user.getPassport().getExpiry());
}*/
/* Query query = session.createQuery("from TPassport");
List list = query.list();
Iterator it = list.iterator();
while(it.hasNext()){
TPassport passport = (TPassport)it.next();
System.out.print(passport.getId() + "\t");
System.out.print(passport.getSerial() + "\t");
System.out.print(passport.getExpiry() + "\t");
System.out.print(passport.getUser().getName() + "\t");
System.out.print(passport.getUser().getGender() + "\t");
System.out.println(passport.getUser().getAge() + "\t");
}*/
/* TUser user = new TUser();
user.setName("wangwu");
user.setAge(new Integer(40));
user.setGender("male");
TPassport passport = new TPassport();
passport.setSerial("American");
passport.setExpiry(new Integer(10));
user.setPassport(passport);
passport.setUser(user);
Transaction tran = null;
try{
tran = session.beginTransaction();
session.save(user);
tran.commit();
}catch(HibernateException e){
e.printStackTrace();
if(tran != null)
tran.rollback();
}*/
}
}
完成了。