Mega Code Archive
HSQL Join Two Classes
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File: Main.java
import java.util.List;
import org.hibernate.Query;
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();
String hql = "select s.name, p.name, p.price from Product p inner join p.supplier as s";
Query query = session.createQuery(hql);
List results = query.list();
System.out.println(results);
session.close();
hibernateUtil.checkData("select * from Product");
hibernateUtil.checkData("select * from Software");
hibernateUtil.checkData("select * from Supplier");
}
}
File: Product.hbm.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="Product">
<id name="id" type="int">
<generator class="increment"/>
</id>
<property name="name" type="string"/>
<property name="description" type="string"/>
<property name="price" type="double"/>
<many-to-one name="supplier" class="Supplier" column="supplierId"/>
</class>
<query name="Product.HQLpricing">
select product.price from Product product
</query>
<sql-query name="Product.SQLpricing">
<return-scalar column="price" type="double"/>
select product.price from Product as product
</sql-query>
</hibernate-mapping>
File: Product.java
public class Product
{
private int id;
private Supplier supplier;
private String name;
private String description;
private double price;
public Product()
{
super();
}
public Product(String name, String description, double price)
{
super();
this.name = name;
this.description = description;
this.price = price;
}
public String getDescription()
{
return description;
}
public void setDescription(String description)
{
this.description = description;
}
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;
}
public Supplier getSupplier()
{
return supplier;
}
public void setSupplier(Supplier supplier)
{
this.supplier = supplier;
}
public double getPrice()
{
return price;
}
public void setPrice(double price)
{
this.price = price;
}
}
File: Software.hbm.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<joined-subclass name="Software" extends="Product">
<key column="Id"/>
<property name="version" type="string"/>
</joined-subclass>
</hibernate-mapping>
File: Software.java
public class Software extends Product
{
private String version;
public Software()
{
super();
}
public Software(String name, String description, double price, String version)
{
super(name, description, price);
this.setVersion(version);
}
public String getVersion()
{
return version;
}
public void setVersion(String version)
{
this.version = version;
}
}
File: Supplier.hbm.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="Supplier" >
<id name="id" type="int">
<generator class="increment"/>
</id>
<property name="name" type="string"/>
<bag name="products" inverse="true" cascade="all,delete-orphan">
<key column="supplierId"/>
<one-to-many class="Product"/>
</bag>
</class>
</hibernate-mapping>
File: Supplier.java
import java.util.ArrayList;
import java.util.List;
public class Supplier
{
private int id;
private String name;
private List products = new ArrayList();
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;
}
public List getProducts()
{
return products;
}
public void setProducts(List products)
{
this.products = products;
}
}
File: HibernateUtil.java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
Session session;
Statement st;
public HibernateUtil() throws Exception{
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
session = sessionFactory.openSession();
// Load the JDBC driver.
Class.forName("org.hsqldb.jdbcDriver");
System.out.println("Driver Loaded.");
// Establish the connection to the database.
String url = "jdbc:hsqldb:data/tutorial";
Connection conn = DriverManager.getConnection(url, "sa", "");
System.out.println("Got Connection.");
st = conn.createStatement();
}
public Session getSession(){
return session;
}
public void executeSQLCommand(String sql) throws Exception {
st.executeUpdate(sql);
}
public void checkData(String sql) throws Exception {
ResultSet rs = st.executeQuery(sql);
ResultSetMetaData metadata = rs.getMetaData();
for (int i = 0; i < metadata.getColumnCount(); i++) {
System.out.print("\t"+ metadata.getColumnLabel(i + 1));
}
System.out.println("\n----------------------------------");
while (rs.next()) {
for (int i = 0; i < metadata.getColumnCount(); i++) {
Object value = rs.getObject(i + 1);
if (value == null) {
System.out.print("\t ");
} else {
System.out.print("\t"+value.toString().trim());
}
}
System.out.println("");
}
}
}
File: hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">org.hsqldb.jdbcDriver</property>
<property name="connection.url">jdbc:hsqldb:data/tutorial</property>
<property name="connection.username">sa</property>
<property name="connection.password"></property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.HSQLDialect</property>
<!-- Enable Hibernate's current session context -->
<property name="current_session_context_class">org.hibernate.context.ManagedSessionContext</property>
<property name="hibernate.cache.use_second_level_cache">false</property>
<property name="hibernate.cache.use_query_cache">false</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Mapping files -->
<mapping resource="Product.hbm.xml"/>
<mapping resource="Software.hbm.xml"/>
<mapping resource="Supplier.hbm.xml"/>
</session-factory>
</hibernate-configuration>
]]>