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Hibernate Select Query


 
In previous article we learnt to implement Hibernate 4 Insert Query example in Eclipse, In this article I will implement an example on loading the object from the database(Select Query) using Hibernate.
 

Project Structure

 

 

Entity class

 

package entity;

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

@Entity
@Table(name = "STUDENT")
public class StudentEntity {

	@Id
	@Column(name = "ID")
	private int id;
	
	@Column(name = "NAME")
	private String name;
	
	@Column(name = "DEPARTMENT")
	private String department;
	
	@Column(name = "COLLEGE")
	private String college;

// Create Getters and Setters
}

 
Note: I have explained about every annotations used in the above file in the article Generic Hibernate Application Requirements
 

Hibernate Configuration file

 
Create a new XML file and give this new configuration file the default name hibernate.cfg.xmland place it src directory of your project.
 
File: hibernate.cfg.xml






	
	
                  oracle.jdbc.driver.OracleDriver
        
	system
	admin
	
                   jdbc:oracle:thin:@xxx.x.x.x:1521:XE
        

	
	org.hibernate.dialect.Oracle10gDialect

	
	true

	
	update
	
    



 

Hibernate Utility

 

package util;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

import entity.StudentEntity;

public class HibernateUtil {

   public static void main(String[] args) {

     Configuration cf = new Configuration().configure("hibernate.cfg.xml");
 
     StandardServiceRegistryBuilder srb = new StandardServiceRegistryBuilder();
     srb.applySettings(cf.getProperties());
     ServiceRegistry sr = srb.build();
     SessionFactory sf = cf.buildSessionFactory(sr);

     Session session = sf.openSession();
     StudentEntity std = (StudentEntity) session.load(StudentEntity.class, new Integer(1));

     // For loading Transaction object is not necessary
     System.out.println("Loaded object Student name is: " + std.getName());

     System.out.println("Object Loaded successfully.....!!");
     session.close();
     sf.close();
     }
}

 
In the article Steps to be followed to use Hibernate in Java, I have explained the configuration/code used in above program in detail.
 

Data in Database

 

 

Run it – Eclipse Console

 

 

Note

 
In hibernate we have 2 methods to load the object from the database, they are get and load. To know the difference between get and load method read the article here.