HQL Select clause example

The below example shows how to use select clause for the HQL and then retrieve values.

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
        <property name="connection.username">hr</property>
        <property name="connection.password">hr</property>

        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.OracleDialect</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>

        <!-- Drop and re-create the database schema on startup -->
        <property name="hbm2ddl.auto">create</property>

        <!-- Names the annotated entity class -->
        <mapping class="com.ram.dao.Student"/>

    </session-factory>

</hibernate-configuration>

File: com.ram.dao.Student.java

package com.ram.dao;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class Student {
 @Id @GeneratedValue
 private int studentId;
 private String studentName;
 
 public int getStudentId() {
  return studentId;
 }
 public void setStudentId(int studentId) {
  this.studentId = studentId;
 }
 public String getStudentName() {
  return studentName;
 }
 public void setStudentName(String studentName) {
  this.studentName = studentName;
 }
}

File: com.ram.hibernate.HQLSelectExample.java

package com.ram.hibernate;

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;

import com.ram.dao.Student;

public class HQLSelectExample {
 public static void main(String[] args) {
  SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
  Session session = sessionFactory.openSession();
  session.beginTransaction();
  
  Query query = session.createQuery("select studentId, studentName from Student");
  query.setFirstResult(3);
  query.setMaxResults(5);
  
  List<Student> students = query.list();
  Iterator it = students.iterator();
  
  while(it.hasNext()){
   Object[] obj = (Object[]) it.next();
   int id = (Integer) obj[0];
   String name = (String) obj[1];
   System.out.print("Student Id = "+id);
   System.out.println("\t Student Name = "+name);
  }
  
  session.getTransaction().commit();
  session.close();
 }
}

Execute HQLSelectExample.java and you get the output as shown below.