一 一個類繼承體系一張表

1 物件模型(java類結構)

2 對映後據庫中的表

3 程式碼

Employee.java

package com.learning;

public class Employee {
	
	private int id;
	
	private String name;

	
	
	public Employee() {
		
	}

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	
	
}
 

Sales.java

package com.learning;

public class Sales extends Employee{
	
	private String sell;
	
	
	
	public Sales() {
		
	}

	public String getSell() {
		return sell;
	}

	public void setSell(String sell) {
		this.sell = sell;
	}
	
	
}

Skiller.java

package com.learning;

public class Skiller extends Employee {
	
	private String skill;

	
	
	public Skiller() {
		
	}

	public String getSkill() {
		return skill;
	}

	public void setSkill(String skill) {
		this.skill = skill;
	}
	
	
}
 

Employee.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 <hibernate-mapping package="com.learning">
 	<class table="employee" name="Employee" discriminator-value="employee">
 		<id name="id">
 		 	<generator class="native"/>
 		</id>
 		<discriminator column="type" type="string"/>
 		<property name="name" column="name"/>
 		<subclass name="Skiller" discriminator-value="skiller">
 			<property name="skill" />
 		</subclass>
 		<subclass name="Sales" discriminator-value="sales">
 			<property name="sell" />
 		</subclass>
 	</class>
 </hibernate-mapping> 
 

測試類 

ExtendsOneTest.java

package com.test;

import java.util.Date;
import java.util.List;

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

import com.learning.Employee;
import com.learning.Sales;
import com.learning.Skiller;


public class ExtendsOneTest {
	private SessionFactory sessionFactory;
	{
		this.init();
	}

	private void init(){
		  Configuration cfg = new Configuration();
		  sessionFactory= cfg.configure().buildSessionFactory();
	}
	
	/**
	 * 公用一張表
	 * */
	private void test(){
		Session session = this.sessionFactory.openSession();
		session.beginTransaction();
		
		Employee employee = new Employee();
		employee.setName("employee name");
	
		Skiller skiller = new Skiller();
		skiller.setName("skiller name");
		skiller.setSkill("skill");
	
		Sales sales = new Sales();
		sales.setSell("sales name");
		sales.setSell("sell");
		
		session.save(employee);
		session.save(skiller);
		session.save(sales);
	
		session.getTransaction().commit();
        session.close();
         
	}

	public static void main(String[] args) {
		ExtendsOneTest extendsOneTest = new ExtendsOneTest();
		extendsOneTest.test();
	}

}

資料庫結果

二 每個子類不同的部分用一張表

1 物件模型(java類結構)與上面相同

2 對映後據庫中的表

3 程式碼

Employee.java ，Sales.java,Skiller.java與上面相同

Employee.hbm.xml對映檔案

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 <hibernate-mapping package="com.learning">
 	<class table="employee" name="Employee">
 		<id name="id">
 		 	<generator class="native"/>
 		</id>
 		<property name="name" column="name"/>
 		<joined-subclass name="Skiller" table="skiller">
 			<key column="emp_id"/>
 			<property name="skill" />
 		</joined-subclass>
 		<joined-subclass name="Sales" table="sales">
 			<key column="emp_id"/>
 			<property name="sell" />
 		</joined-subclass>
 		
 	</class>
 </hibernate-mapping> 

測試類與ExtendsOneTest.java相同

資料庫中結果

三 繼承關係與內連線結合

混合使用”一個類繼承體系一張表”和”每個子類一張表”

1 物件模型(java類結構)與上面相同

2 對映後據庫中的表

3程式碼

Employee.java ,Sales.java和Skiller.java與上面一樣

Employee.hbm.xml對映檔案

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 <hibernate-mapping package="com.learning">
 <class table="employee" name="Employee" discriminator-value="employee">
 		<id name="id">
 		 	<generator class="native"/>
 		</id>
 		<discriminator column="type" type="string"/>
 		<property name="name" column="name"/>
 		<subclass name="Skiller" discriminator-value="skiller">
 			<property name="skill" />
 		</subclass>
 		<subclass name="Sales" discriminator-value="sales">
 			<join table="sales">
 				<key column="emp_id" />
 				<property name="sell" />
 			</join>
 		</subclass>
 	</class>	
 </hibernate-mapping> 

資料庫截圖

四 每個具體類一張表

1 物件模型(java類結構)與上面一樣

2 對映後的結果

3程式碼

Employee.java , Sales.java和Skiller.java與上面相同

Employee.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 <hibernate-mapping package="com.learning">
 <class table="employee" name="Employee" >
 		<id name="id">
 		 	<generator class="hilo"/>
 		</id>
 		<property name="name" column="name"/>
 		<union-subclass name="Skiller" table="skiller">
 			<property name="skill" />
 		</union-subclass>
 		<union-subclass name="Sales" table="sales">
 			<property name="sell" />
 		</union-subclass>
 		
 	</class>	
 </hibernate-mapping> 

測試類與上面相同

資料庫結果