Hibernate Named Query Example

Let us see an example on Hibernate Named Queries

files required…

• Product.java(POJO class)
• Product.hbm.xml
• hibernate.cfg.xml
• ForOurLogic.java (For writing our business logic)

• Product.java

  1234567891011121314151617181920212223242526272829303132333435package str;
  
  public class Product{
  
  	private int productId;
  	private String proName;
  	private double price;
  
  	public void setProductId(int productId)
  	{
  	    this.productId = productId;
  	}
  	public int getProductId()
  	{
  	    return productId;
  	}
  
  	public void setProName(String proName)
  	{
  	    this.proName = proName;
  	}
  	public String getProName()
  	{
  	    return proName;
  	}
  
  	public void setPrice(double price)
  	{
  	    this.price = price;
  	}
  	public double getPrice()
  	{
  	    return price;
  	}
  }

  Product.hbm.xml

  12345678910111213141516171819<?xml version="1.0"?>
  <!DOCTYPE hibernate-mapping PUBLIC
  "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
  "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
  
  <hibernate-mapping>
  <class name="str.Product" table="products">
  
  <id name="productId" column="pid"  />
  <property name="proName" column="pname" length="10"/>
  <property name="price"/>
  
  </class>
  
  

  <query name="Myquery">

  <![CDATA[from Product p where p.price>:java4s ]]>

  </query>

  </hibernate-mapping>

  hibernate.cfg.xml

  1234567891011121314151617181920<?xml version='1.0' encoding='UTF-8'?>
  <!DOCTYPE hibernate-configuration PUBLIC
  "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
  "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
  
  <hibernate-configuration>
  <session-factory>
  <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver
  </property>
  <property name="connection.url">jdbc:oracle:thin:@www.java4s.com:1521:XE</property>
  <property name="connection.username">system</property>
  <property name="connection.password">admin</property>
  
  <property name="dialect">org.hibernate.dialect.OracleDialect</property>
  <property name="show_sql">true</property>
  <property name="hbm2ddl.auto">update</property>
  
  <mapping resource="Product.hbm.xml"></mapping>
  </session-factory>
  </hibernate-configuration>

  ForOurLogic.java

  1234567891011121314151617181920212223242526272829303132333435363738394041package str;
  
  import java.util.Iterator;
  import java.util.List;
  
  import org.hibernate.Query;
  import org.hibernate.Session;
  import org.hibernate.SessionFactory;
  import org.hibernate.cfg.Configuration;
  
  public class ForOurLogic { 
  
  	@SuppressWarnings("unchecked")
  	public static void main(String[] args)
  	{
  
  		Configuration cfg = new Configuration();
  		cfg.configure("hibernate.cfg.xml"); 
  
  		SessionFactory factory = cfg.buildSessionFactory();
  		Session session = factory.openSession();
  
  

  Query qry=session.getNamedQuery("Myquery");

  qry.setParameter("java4s", new Double(15000));

  List l=qry.list(); System.out.println("List total size..._"+l.size()); Iterator it=l.iterator(); while(it.hasNext()) { Product p=(Product)it.next(); System.out.println(p.getProductId()+" "+p.getProName()+" "+p.getPrice()); System.out.println("-----------------"); } session.close(); factory.close(); } }

  Notes:

• See Product.hbm.xml file, line numbers 15, 16, 17, we have given one HQL query in the <query /> element
• In ForOurLogic.java file, line number 23 will get that query from mapping xml into Query object, in line 24 we just passed the value to that label normally

• But if you would like to use Named Query with Native SQL, then we need to change our mapping file like…

   

  Product.hbm.xml

  12345678910111213141516171819<?xml version="1.0"?>
  <!DOCTYPE hibernate-mapping PUBLIC
  "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
  "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
  
  <hibernate-mapping>
  <class name="str.Product" table="products">
  
  <id name="productId" column="pid"  />
  <property name="proName" column="pname" length="10"/>
  <property name="price"/>
  
  </class>
  
  

  <sql-query name="Myquery">

  select * from PRODUCTS

  </sql-query>

  </hibernate-mapping>

  Note: In this case we need to use one new element <sql-query /> unlike <query /> element which we used to write HQL query