Hibernate Max() Function (Aggregate Functions)


In this section, we will show you, how to use the Max() function. Hibernate supports multiple aggregate functions. When they are used in HQL queries, they return an aggregate value ( such as avg(...), sum(...), min(...), max(...) , count(*), count(...), count(distinct ...), count(all...) ) calculated from property values of all objects satisfying other query criteria. 
Following is a aggregate function (max() function) with their respective syntax.
max( [ distinct | all ] object.property)
The Max() function aggregates the maximum value of the given column. 
Table Name: insurance
ID
insurance_name
invested_amount
investement_date
2
Life Insurance
25000
0000-00-00 00:00:00
1
Givan Dhara
20000 
2007-07-30 17:29:05
3
Life Insurance
 500
2005-10-15 00:00:00
4
Car Insurance 
 2500
2005-01-01 00:00:00
5
Dental Insurance
500
2004-01-01 00:00:00
6 
Life Insurance
900
2003-01-01 00:00:00
7 
Travel Insurance
 2000 
2005-02-02 00:00:00
Here is the java code to retrieve the maximum value of "invested_amount" column from insurance table:
package roseindia.tutorial.hibernate;

import java.util.Iterator;
import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

public class HibernateHQLMaxFunction {

  /**
 * mail_mevinod@yahoo.co.in
 */
  public static void main(String[] args) {
  // TODO Auto-generated method stub

  Session sess = null;
  try {
  SessionFactory fact = new 
Configuration().configure().buildSessionFactory();
  sess = fact.openSession();
  String SQL_QUERY = "select 
max(investementAmount)from Insurance insurance";
  Query query = sess.createQuery(SQL_QUERY);
  List list = query.list();
  System.out.println("Max 
Invested Amount: " + list.get(0)); 
  sess.close();
  }
  catch(Exception e){
  System.out.println(e.getMessage());
  }
  }
}

Output:
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Hibernate: select max(insurance0_.invested_amount) as col_0_0_ from insurance insurance0_
Max Invested Amount: 25000

Comments

Post a Comment

Popular posts from this blog

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

Hibernate Avg() Function (Aggregate Functions)

In this section, we will show you, how to use the avg() function. Hibernate supports multiple aggregate functions. When they are used in HQL queries, they return an aggregate value ( such as   avg(...), sum(...), min(...), max(...) , count(*), count(...), count(distinct ...), count(all...)   ) calculated from property values of all objects satisfying other query criteria.  Following is a aggregate function (avg() function) with their respective syntax. avg(   [   distinct   |   all   ] object.property): The   avg()   function aggregates the average value of the given column.  Table Name: insurance ID insurance_name invested_amount investement_date 2 Life Insurance 25000 0000-00-00 00:00:00 1 Givan Dhara 20000  2007-07-30 17:29:05 3 Life Insurance   500 2005-10-15 00:00:00 4 Car Insurance    2500 2005-01
Read more

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