對於如下關係：

Person.java

package com.hust.PO;

public class Person {
     private Integer id;
     private String name;
     private Integer age;
     private String sex;
	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 Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
    
}
 

package com.hust.PO;

public class Student extends Person {
       private String sno;    //學號
       private String school;  //學校
	public String getSno() {
		return sno;
	}
	public void setSno(String sno) {
		this.sno = sno;
	}
	public String getSchool() {
		return school;
	}
	public void setSchool(String school) {
		this.school = school;
	}     
}
 

package com.hust.PO;

public class Worker extends Person {
	 private String wno;      //工號
     private Double salary;   //工資
	public String getWno() {
		return wno;
	}
	public void setWno(String wno) {
		this.wno = wno;
	}
	public Double getSalary() {
		return salary;
	}
	public void setSalary(Double salary) {
		this.salary = salary;
	}
     
} 
 

欄位“Type”是鑑別器，通過它區分student和worker物件例項

Person.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 package="com.hust.PO">
    <!-- 一個繼承樹一張表 -->  
    <!-- 父類 -->  
    <class name="Person" table="person">  
        <id column="id" name="Id" type="integer">  
            <!-- 主鍵生成策略為 '分配'  -->  
            <generator class="assigned"></generator>  
        </id>  
        <!-- 鑑定列，區分列 discriminator 鑑別器-->  
        <discriminator column="Type" type="string"></discriminator>
          
        <property column="Name" name="name" type="string"></property>  
        <property column="Age" name="age" type="integer"></property>  
        <property column="Sex" name="sex" type="string"></property>  
      
    <!-- 子類，其鑑定列值為'stu' name是PO類名-->  
    <subclass name="Student" discriminator-value="stu">  
        <property column="School" name="school" type="string"></property>  
        <property column="Sno" name="sno" type="string"></property>  
    </subclass>  
          
    <!-- 子類，其鑑定列值為'worker' name是PO類名-->  
    <subclass name="Worker" discriminator-value="worker">  
        <property column="Wno" name="wno" type="string"></property>  
        <property column="Salary" name="salary" type="double"></property>  
    </subclass>  
         
    </class>  
</hibernate-mapping>

subclass標籤就是為子類嵌入父類的表中而設計的，而且要指定鑑別器，即用subclass一定要有判斷型別的一個列，鑑別器指定記錄屬於哪個型別

OneTableDao.java

package com.hust.Dao;
import org.hibernate.Session;
import org.hibernate.Transaction;
import SessionFactory.HibernateSessionFactory;
import com.hust.PO.Student;
import com.hust.PO.Worker;

public class OneTableDao {
     //儲存學生資訊，執行該段程式碼後，程式會根據Student類設定person表中的Type值為“stu”，並把值插入到person表中，其他沒有的屬性都是空值
	public void saveStu(Student stu){
		  Session session=HibernateSessionFactory.getSession();
		    Transaction ts=null;
		    try{
		    	ts=session.beginTransaction();		        
		    	session.saveOrUpdate(stu);
		    	ts.commit();
		    }catch(Exception ex){
		    	ts.rollback();
		    	System.out.println("新增學生資訊失敗！");
		    }finally{
		    	HibernateSessionFactory.closeSession();
		    }
	}
	//獲取學生資訊，會自動根據資料表字段“Type”的值，選擇記錄
	 public Student loadStu(Integer id){
		     Session session=HibernateSessionFactory.getSession();
		    Transaction ts=null;
		    Student stu=null;
		    try{
		    	ts=session.beginTransaction();
		    	stu=(Student)session.get(Student.class, id);
		    	ts.commit();
		    }catch(Exception ex){
		    	ts.rollback();
		    	System.out.println("獲取學生資訊失敗！");
		    }finally{
		    	HibernateSessionFactory.closeSession();
		    }
		    return stu;
	 }
	//儲存工人資訊，，執行該段程式碼後，程式會根據Worker類設定person表中的Type值為“worker”，並把值插入到person表中，其他沒有的屬性都是空值
		public void saveWorker(Worker worker){
			  Session session=HibernateSessionFactory.getSession();
			    Transaction ts=null;
			    try{
			    	ts=session.beginTransaction();		        
			    	session.saveOrUpdate(worker);
			    	ts.commit();
			    }catch(Exception ex){
			    	ts.rollback();
			    	System.out.println("新增工人資訊失敗！");
			    }finally{
			    	HibernateSessionFactory.closeSession();
			    }
		}
		//獲取工人資訊
		 public Worker loadWorker(Integer id){
		     Session session=HibernateSessionFactory.getSession();
		    Transaction ts=null;
		    Worker worker=null;
		    try{
		    	ts=session.beginTransaction();
		    	worker=(Worker)session.get(Worker.class, id);
		    	ts.commit();
		    }catch(Exception ex){
		    	ts.rollback();
		    	System.out.println("獲取工人資訊失敗！");
		    }finally{
		    	HibernateSessionFactory.closeSession();
		    }
		    return worker;
	 }	
	
}

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page import="com.hust.Dao.*" %>
<%@ page import="com.hust.PO.*" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>hibernate的繼承關係一個繼承樹一張表</title>
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->
  </head>
  <body>
      <h2>hibernate的繼承關係一個繼承樹一張表</h2>
      <hr>
      <%
         Student stu=new Student();
         stu.setId(new Integer(1));
         stu.setName("tuke");
         stu.setAge(new Integer(22));
         stu.setSex("nan");
         stu.setSno("M201571885");
         stu.setSchool("Hust");
         //儲存stu物件
         OneTableDao dao=new OneTableDao();
         dao.saveStu(stu);
         //從資料庫中獲取stu物件
         Student stu1=dao.loadStu(stu.getId());
         out.println("<br>資料庫中的學生姓名："+stu1.getName());
         out.println("<br>資料庫中的學生學號："+stu1.getSno());
         out.println("<br>資料庫中的學生學校："+stu1.getSchool());
         out.println("<br>");
         
         Worker worker=new Worker();
         worker.setId(new Integer(2));
         worker.setName("zhangsan");
         worker.setAge(new Integer(50));
         worker.setSex("nan");
         worker.setWno("W20152223");
         worker.setSalary(new Double(6409.32));
         //儲存工人物件
         dao.saveWorker(worker);
         //從資料庫中獲取工人物件
         Worker worker2=dao.loadWorker(worker.getId());
         out.println("<br>資料庫中的工人姓名："+worker2.getName());
         out.println("<br>資料庫中的工人工號："+worker2.getWno());
         out.println("<br>資料庫中的工人工資："+worker2.getSalary());
       %>
  </body>
</html>

Hibernate: 
    select
        student_.id,
        student_.Name as Name0_,
        student_.Age as Age0_,
        student_.Sex as Sex0_,
        student_.School as School0_,
        student_.Sno as Sno0_ 
    from
        person student_ 
    where
        student_.id=?
Hibernate: 
    insert 
    into
        person
        (Name, Age, Sex, School, Sno, Type, id) 
    values
        (?, ?, ?, ?, ?, 'stu', ?)        //插入stu執行的語句
Hibernate: 
    select
        student0_.id as id0_0_,
        student0_.Name as Name0_0_,
        student0_.Age as Age0_0_,
        student0_.Sex as Sex0_0_,
        student0_.School as School0_0_,
        student0_.Sno as Sno0_0_ 
    from
        person student0_ 
    where
        student0_.id=? 
        and student0_.Type='stu'        // 載入stu資訊時執行的語句
Hibernate: 
    select
        worker_.id,
        worker_.Name as Name0_,
        worker_.Age as Age0_,
        worker_.Sex as Sex0_,
        worker_.Wno as Wno0_,
        worker_.Salary as Salary0_ 
    from
        person worker_ 
    where
        worker_.id=?
Hibernate: 
    insert 
    into
        person
        (Name, Age, Sex, Wno, Salary, Type, id) 
    values
        (?, ?, ?, ?, ?, 'worker', ?)    //插入worker執行的語句
Hibernate: 
    select
        worker0_.id as id0_0_,
        worker0_.Name as Name0_0_,
        worker0_.Age as Age0_0_,
        worker0_.Sex as Sex0_0_,
        worker0_.Wno as Wno0_0_,
        worker0_.Salary as Salary0_0_ 
    from
        person worker0_ 
    where
        worker0_.id=? 
        and worker0_.Type='worker'    //載入worker執行的語句