Hibernate Select Clause


In this lesson we will write example code to select the data from Insurance table using Hibernate Select Clause. The select clause picks up objects and properties to return in the query result set. Here is the query:
Select insurance.lngInsuranceId, insurance.insuranceName, insurance.investementAmount, insurance.investementDate from Insurance insurance
which selects all the rows (insurance.lngInsuranceId, insurance.insuranceName, insurance.investementAmount, insurance.investementDate) from Insurance table.
Hibernate generates the necessary sql query and selects all the records from Insurance table. Here is the code of our java file which shows how select HQL can be used:

package roseindia.tutorial.hibernate;

import org.hibernate.Session;
import org.hibernate.*;
import org.hibernate.cfg.*;

import java.util.*;

/**
 * @author Deepak Kumar
 *
 * http://www.roseindia.net
 * HQL Select Clause Example
 */
public class SelectClauseExample {
  public static void main(String[] args) {
  Session session = null;

  try{
  // This step will read hibernate.cfg.xml 
and prepare hibernate for use
  SessionFactory sessionFactory = new 
Configuration().configure()
.buildSessionFactory();
  session =sessionFactory.openSession();
 
  //Create Select Clause HQL
 String SQL_QUERY ="Select insurance.
lngInsuranceId,insurance.insuranceName," + 
 "insurance.investementAmount,insurance.
investementDate from Insurance insurance";
 Query query = session.createQuery(SQL_QUERY);
 for(Iterator it=query.iterate();it.hasNext();){
 Object[] row = (Object[]) it.next();
 System.out.println("ID: " + row[0]);
 System.out.println("Name: " + row[1]);
 System.out.println("Amount: " + row[2]);
 }
 
  session.close();
  }catch(Exception e){
  System.out.println(e.getMessage());
  }finally{
  }
  }
}
To run the example select Run-> Run As -> Java Application from the menu bar. Following out is displayed in the Eclipse console:
Hibernate: select insurance0_.ID as col_0_0_, insurance0_.insurance_name as col_1_0_, insurance0_.invested_amount as col_2_0_, insurance0_.investement_date as col_3_0_ from insurance insurance0_
ID: 1
Name: Car Insurance
Amount: 1000
ID: 2
Name: Life Insurance
Amount: 100
ID: 3
Name: Life Insurance
Amount: 500
ID: 4
Name: Car Insurance
Amount: 2500
ID: 5
Name: Dental Insurance
Amount: 500
ID: 6
Name: Life Insurance
Amount: 900
ID: 7
Name: Travel Insurance
Amount: 2000
ID: 8
Name: Travel Insurance
Amount: 600
ID: 9
Name: Medical Insurance
Amount: 700
ID: 10
Name: Medical Insurance
Amount: 900
ID: 11
Name: Home Insurance
Amount: 800
ID: 12
Name: Home Insurance
Amount: 750
ID: 13
Name: Motorcycle Insurance
Amount: 900
ID: 14
Name: Motorcycle Insurance
Amount: 780

Comments

Post a Comment

Popular posts from this blog

Hibernate Count Query

In this section we will show you, how to use the Count Query. Hibernate supports multiple aggregate functions. when they are used in HQL queries, they return an aggregate value (such as sum, average, and count) calculated from property values of all objects satisfying other query criteria. These functions can be used along with the  distinct  and all  options, to return aggregate values calculated from only  distinct  values and all values (except null values), respectively. Following is a list of aggregate functions with their respective syntax; all of them are self-explanatory. count ( [   distinct   |   all   ] object | object.property ) count(*)  (equivalent to   count(all ...) , counts null values also) sum (   [   distinct   |   all   ] object.property) avg(   [   distinct   |   all   ] object.property) max(   [   distinct   |   all   ] object.property) min(  [  distinct  |  all  ] object.property) Here is the java code for counting the records from insurance tab
Read more

STRUTS ACTION - AGGREGATING ACTIONS IN STRUTS

If you are a Struts developer then you might have experienced the pain of writing huge number of Action classes for your project. The latest version of struts provides classes using which you can aggregate a related set of actions into a single unified action. In this article we will see how to achieve this. Struts provides four important classes for this purpose. These classes are called as Dispatchers. The important Dispatchers that struts provides includes :   DispatchAction ,   ActionDispatcher   ,   LookupDispatchAction   and MappingDispatchAction . All these classes can be found in the package   org.apache.struts.actions . Let us look in to each of these in detail. Our examples use the simple CRUD actions. DispatchAction:   In this type of aggregation, the action class must extend DispatchAction class as shown. public final class CRUDDispatchAction extends DispatchAction { public ActionForward create(ActionMapping mapping, ActionForm form, HttpServletRequest reque
Read more

Servlets, JSP, Struts and MVC

Image
1.General Information about servlet: Servlet Request & Response Model: There are three different players in this picture: browser, web server, and servlet Container. In many cases, a web server and a servlet container are running in a same machine even in a single virtual machine. So they are not really distinguished in many cases. Anyway, the role of the web server is to receive HTTP request and then passes it to the web container or servlet container Which then creates Java objects that represent “HTTP request” and a “session” and then dispatches the request to the servlet by invoking service() method defined in the servlet.         The most common form of client requests are HTTP GET and HTTP POST requests. In the HTTP GET request, the user entered information is appended to the URL as a query string. In the HTTP POST request, on the other hand, the user entered information is sent as data. Servlet Classes and Interfaces: This picture shows important
Read more