hibernate 一对多单向、双向关联

一个老师 -- 关联 多个学生

create table STUDENT  (
   ID                   NUMBER(16)                      not null,
   STUDENT_NAME              VARCHAR(20),
   TEACHER_ID           NUMBER(16),
   constraint PK_STUDENT primary key (ID)
);

create table TEACHER  (
   ID                   NUMBER(16)                      not null,
   TEACHER_NAME         VARCHAR(22),
   constraint PK_TEACHER primary key (ID)
);

---PO---
public class Teacher implements java.io.Serializable {

	// Fields

	private Long id;
	private String teacherName;

public class Student implements java.io.Serializable {

	// Fields

	private Long id;
	private String studentName;
	private Long teacherId;
	private Teacher teacher;  // 老师

配置文件
<hibernate-mapping>
    <class name="com.po.Teacher" table="TEACHER">
        <id name="id" type="java.lang.Long">
            <column name="ID" precision="16" scale="0" />
            <generator class="sequence" />
        </id>
        <property name="teacherName" type="java.lang.String">
            <column name="TEACHER_NAME" length="22" />
        </property>
    </class>
</hibernate-mapping>

<hibernate-mapping>
    <class name="com.po.Student" table="STUDENT">
        <id name="id" type="java.lang.Long">
            <column name="ID" precision="16" scale="0" />
            <generator class="sequence" />
        </id>
        <property name="studentName" type="java.lang.String">
            <column name="STUDENT_NAME" length="20" />
        </property>
        <property name="teacherId" type="java.lang.Long">
            <column name="TEACHER_ID" precision="16" scale="0" />
        </property>
        <many-to-one name="teacher" class="com.po.Teacher" column="teacher_id" fetch="select" lazy="false" cascade="save-update"></many-to-one>
    </class>
</hibernate-mapping>

测试代码

/**
 * Test.java
 * com.hib
 *
 * Function： TODO 
 *
 *   ver     date      		author
 * ──────────────────────────────────
 *   		 Mar 31, 2010 		程仁银
 *
 * Copyright (c) 2010,  All Rights Reserved.
*/

package com.hib;

import java.util.List;

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

import com.po.Address;
import com.po.Person;
import com.po.Student;

/**
 * ClassName:Test
 * Project: 
 * Company: LINKAGE
 *
 * @author   程仁银
 * @version  
 * @since    Ver 1.1
 * @Date	 Mar 31, 2010		1:56:43 PM
 *
 * @see 	 
 */
public class Test {

	/**@author . 程仁银
	 * @email  . [e-mail]
	 * @createTime .Mar 31, 2010 1:56:44 PM
	 * @parameters . 
	 * @description .
	 */
	public static void main(String[] args) 
	{
		SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
		Session session = sessionFactory.openSession();
		Transaction tx = session.beginTransaction();
//		业务逻辑测试
	
		Query query=session.createQuery("from Student u");
		List<Student> list = query.list();
		for(Student s:list)
		{
			System.out.println(
					s.getId()+" "+s.getStudentName()+
					"======"+s.getTeacher().getTeacherName());
		}
		tx.commit();
	}

}

配置下双向关联
在原有的基础上修改，主要是修改teacher
public class Teacher implements java.io.Serializable {

	// Fields

	private Long id;
	private String teacherName;
	
	private Set<Student> student = new HashSet<Student>();
 <class name="com.po.Teacher" table="TEACHER">
        <id name="id" type="java.lang.Long">
            <column name="ID" precision="16" scale="0" />
            <generator class="sequence" />
        </id>
        <property name="teacherName" type="java.lang.String">
            <column name="TEACHER_NAME" length="22" />
        </property>
        <set name="student" inverse="true" fetch="select" cascade="save-update" lazy="true">
        	<key column="teacher_id"></key>
        	<one-to-many class="com.po.Student"/>
        </set>
    </class>