hibernate3学习笔记(十九)｜关系映射：一对一

A.唯一外键关联

DDL：

CREATE TABLE user (
    id INT(11) NOT NULL auto_increment PRIMARY KEY,
    name VARCHAR(100) NOT NULL default '',
    room_id INT(11)
);


    
CREATE TABLE room (
    id INT(11) NOT NULL auto_increment PRIMARY KEY,
    address VARCHAR(100) NOT NULL default ''
);

User.java

package com.hb3.pack_02.model;


    
public class User {


    
    private Integer id;
    private String name;
    private Room room;
    
    public User() {
    }


    
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Room getRoom() {
        return room;
    }
    public void setRoom(Room room) {
        this.room = room;
    }
}

Room.java

package com.hb3.pack_02.model;


    
public class Room {


    
    private Integer id; 
    private String address;
    private User user;
    
    public Room() {
    }
    
    public Integer getId() { 
        return id; 
    } 
    public void setId(Integer id) { 
        this.id = id; 
    }
    public String getAddress() { 
        return address; 
    }
    public void setAddress(String address) { 
        this.address = address; 
    }
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
}

User.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> 

    <class name="com.hb3.pack_02.model.User" table="user"> 
        <id name="id" column="id" type="java.lang.Integer"> 
            <generator class="native"/> 
        </id> 

        <property name="name" column="name" type="java.lang.String"/> 
        
        <many-to-one name="room" 
                     column="room_id" 
                     class="com.hb3.pack_02.model.Room"
                     cascade="all"
                     outer-join="true"
                     unique="true"/>    
    </class> 

</hibernate-mapping>

Room.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> 

    <class name="com.hb3.pack_02.model.Room" table="room"> 
        <id name="id" column="id"> 
            <generator class="native"/> 
        </id> 

        <property name="address" 
                  column="address" 
                  type="java.lang.String"/> 
                  
        <one-to-one name="user"
                    class="com.hb3.pack_02.model.User"
                    property-ref="room"/>
    </class> 

</hibernate-mapping>

测试代码：

package com.hb3.pack_02;


    
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;


    
import com.hb3.pack_02.model.Room;
import com.hb3.pack_02.model.User;


    
public class BusinessService {


    
    public static void main(String[] args) {
        
        Configuration config = new Configuration().configure();
        SessionFactory sessionFactory = config.buildSessionFactory();      
        Session session = sessionFactory.openSession();


    
        User user1 = new User();
        user1.setName("shenbin"); 
        Room room1 = new Room(); 
        room1.setAddress("NTU-M8-419");
        user1.setRoom(room1);
   
        User user2 = new User(); 
        user2.setName("chanyan"); 
        Room room2 = new Room(); 
        room2.setAddress("NTU-M8-418");
        user2.setRoom(room2);
      
        Transaction tx = session.beginTransaction();
        session.save(user1);
        session.save(user2);        
        tx.commit();
        
        Room room = (Room) session.load(Room.class, new Integer(1));
        System.out.println(room.getUser().getName());
        
        session.close();
        sessionFactory.close();
    }
}

A.主键关联

DDL：

CREATE TABLE user (
    id INT(11) NOT NULL auto_increment PRIMARY KEY,
    name VARCHAR(100) NOT NULL default ''
);


    
CREATE TABLE room (
    id INT(11) NOT NULL auto_increment PRIMARY KEY,
    address VARCHAR(100) NOT NULL default ''
);

Room和User类同上。

Room.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> 

    <class name="com.hb3.pack_18.model.Room" table="room">
    
        <id name="id" column="id"> 
            <generator class="foreign"> 
                <param name="property">user</param>
            </generator>
        </id> 

        <property name="address" 
                  column="address" 
                  type="java.lang.String"/> 
                  
        <one-to-one name="user"
                    class="com.hb3.pack_18.model.User"
                    constrained="true"/>
    </class> 

</hibernate-mapping>

User.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> 

    <class name="com.hb3.pack_18.model.User" table="user">
     
        <id name="id" column="id" type="java.lang.Integer"> 
            <generator class="native"/> 
        </id> 

        <property name="name" column="name" type="java.lang.String"/> 
        
        <one-to-one name="room" 
                    class="com.hb3.pack_18.model.Room"
                    cascade="all"/>
    </class> 

</hibernate-mapping>

测试代码：

package com.hb3.pack_18;

import java.io.IOException;
import java.sql.SQLException;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import com.hb3.pack_18.model.Room;
import com.hb3.pack_18.model.User;

public class BusinessService {

    public static void main(String[] args) throws IOException, SQLException {
        
        Configuration config = new Configuration().configure();
        SessionFactory sessionFactory = config.buildSessionFactory();      
        Session session = sessionFactory.openSession();

        User user1 = new User();
        user1.setName("chanyan"); 
        Room room1 = new Room(); 
        room1.setAddress("NTU-M8-419");
        user1.setRoom(room1);
        room1.setUser(user1);
                
        User user2 = new User(); 
        user2.setName("shenbin"); 
        Room room2 = new Room(); 
        room2.setAddress("NTU-M8-418");
        user2.setRoom(room2);
        room2.setUser(user2);
                
        Transaction tx = session.beginTransaction();
        session.save(user1);
        session.save(user2);
        tx.commit();

        session.close();
        sessionFactory.close();
    }
}

ExtJS教程- Hibernate教程-Struts2 教程-Lucene教程

发表于 2008-10-29 19:40 淘声依旧阅读(222) 评论(0) 编辑收藏所属分类: 103.Hibernate

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