Java Tutorial/Hibernate/Mapping Inheritance

Class In Hierarchy Has Its Own Table

File: Main.java

   <source lang="java">

import java.util.Iterator; import java.util.List; import org.hibernate.Session; public class Main {

 public static void main(String[] args) throws Exception {
   HibernateUtil hibernateUtil = new HibernateUtil();
   hibernateUtil
       .executeSQLCommand("create table CD(id varchar,title varchar,artist varchar,purchaseDate date,cost decimal(6,2))");
   hibernateUtil
   .executeSQLCommand("create table SECD(id varchar,title varchar,artist varchar,purchaseDate date,cost decimal(6,2), newfeatures varchar)");
   hibernateUtil
   .executeSQLCommand("create table ICD(id varchar,title varchar,artist varchar,purchaseDate date,cost decimal(6,2),languages varchar, region int)");
   Session session = hibernateUtil.getSession();
   CD cd = new CD();
   cd.setArtist("artist");
   cd.setTitle("title");
   
   String id = (String)session.save(cd);
   System.out.println(id);
   
   SpecialEditionCD scd = new SpecialEditionCD();
   scd.setNewfeatures("new");
   session.save(scd);
   
   InternationalCD icd = new InternationalCD();
   icd.setLanguages("ENG");
   session.save(icd);
   
   session.flush();
   List cds = session.createQuery("from CD").list();
   Iterator iter = cds.iterator();
   while (iter.hasNext()) {
     CD cd1 = (CD) iter.next();
     System.out.println(cd1.getArtist());
   }
   session.close();
   hibernateUtil.checkData("select * from CD");
   hibernateUtil.checkData("select * from SECD");
   hibernateUtil.checkData("select * from ICD");
 }

}</source>

Class In Hierarchy Maps To One Table

File: Main.java

   <source lang="java">

import java.util.Iterator; import java.util.List; import org.hibernate.Session; public class Main {

 public static void main(String[] args) throws Exception {
   HibernateUtil hibernateUtil = new HibernateUtil();
   hibernateUtil
       .executeSQLCommand("create table CD(id varchar,title varchar,artist varchar,purchaseDate date,cost decimal(6,2),languages varchar, newfeatures varchar)");

   Session session = hibernateUtil.getSession();
   CD cd = new CD();
   cd.setArtist("artist");
   cd.setTitle("title");
   
   String id = (String)session.save(cd);
   System.out.println(id);
   
   SpecialEditionCD scd = new SpecialEditionCD();
   scd.setNewfeatures("new");
   session.save(scd);
   
   InternationalCD icd = new InternationalCD();
   icd.setLanguages("ENG");
   session.save(icd);
   
   session.flush();
   session.close();
   hibernateUtil.checkData("select * from CD");
 }

}</source>

Mapping Class Hierarchy

File: Main.java

   <source lang="java">

import org.hibernate.Session; public class Main {

 public static void main(String[] args) throws Exception {
   HibernateUtil hibernateUtil = new HibernateUtil();
   hibernateUtil
       .executeSQLCommand("create table Product(id int, name varchar, description varchar, price decimal(6,2), supplierid int)");
    
   hibernateUtil
   .executeSQLCommand("create table Supplier (id int , name varchar)");
   hibernateUtil
   .executeSQLCommand("create table Software(id int, name varchar, description varchar, price decimal(6,2), supplierid int, version varchar)");
   
   Session session = hibernateUtil.getSession();
   Supplier superCorp = new Supplier();
   superCorp.setName("Supplier1");
   session.save(superCorp);
   
   Supplier megaInc = new Supplier();
   megaInc.setName("Supplier2");
   session.save(megaInc);        
   Product mouse = new Product("Product1","first product", 20.0);
   mouse.setSupplier(superCorp);
   superCorp.getProducts().add(mouse);
   session.flush();
   Product mouse2 = new Product("Product2","second product", 22.0);
   mouse2.setSupplier(superCorp);
   superCorp.getProducts().add(mouse2);        
   
   Product keyboard = new Product("Product3", "third product", 30.0);
   keyboard.setSupplier(megaInc);
   megaInc.getProducts().add(keyboard);
   Software webBrowser = new Software("Web Browser","new browser", 75.0, "2.0");
   webBrowser.setSupplier(superCorp);
   superCorp.getProducts().add(webBrowser);
   Software email = new Software("Email","email client", 49.99, "4.1 Edition");
   email.setSupplier(megaInc);
   megaInc.getProducts().add(email);    
   session.flush();
   session.close();
   hibernateUtil.checkData("select * from Product");
   hibernateUtil.checkData("select * from Software");
   hibernateUtil.checkData("select * from Supplier");
 }

}</source>