Hibernate Avg() Function (Aggregate Functions)

In this section, we will show you, how to use the avg() function. Hibernate supports multiple aggregate functions.

Hibernate Avg() Function (Aggregate Functions)

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 2005-01-01 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 average 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.cfg.Configuration;

public class HibernateHQLAvgFunction {

  /**
 * @Vinod kumar
 */
  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 avg
(investementAmount) from Insurance insurance";
  Query query = sess.createQuery(SQL_QUERY);
  List list = query.list();
  System.out.println("Average of 
Invested Amount: " + list.get(0));
  }
  catch(Exception e){
  System.out.println(e.getMessage());
  }
  }

}

Download this Code.

Output:

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).

log4j:WARN Please initialize the log4j system properly.

Hibernate: select avg(insurance0_.invested_amount) as col_0_0_ from insurance insurance0_

Average of Invested Amount: 7342.8571

Tutorials

  1. Why hibernate is used?
  2. Hibernate Native SQL Example
  3. Hibernate Update Query
  4. Hibernate Delete Query
  5. Hibernate Count Query
  6. Writing First Hibernate Code
  7. Running First Hibernate 3.0 Example
  8. Hibernate Book
  9. Understanding Hibernate O/R Mapping
  10. Using Hibernate to generate id incrementally
  11. Hibernate Query Language
  12. Preparing table for HQL Examples
  13. Writing ORM for Insurance table
  14. HQL from clause Example
  15. Hibernate Select Clause
  16. HQL Where Clause Example
  17. Hibernate Architecture
  18. HQL Group By Clause Example
  19. hibernateTemplate-Order Results
  20. Hibernate Criteria Query Example
  21. Hibernate How To
  22. Hibernate Quickly
  23. Hibernate 3.1.2 Released
  24. HQL Order By Example
  25. Hibernate 3.1.3 Released
  26. Hibernate 3.1.1 Released
  27. Introduction to Hibernate 3.0
  28. Complete Hibernate 3.0 and Hibernate 4 Tutorial
  29. Hibernate Avg() Function (Aggregate Functions)
  30. Hibernate Max() Function (Aggregate Functions)
  31. Hibernate Min() Function (Aggregate Functions)
  32. Hibernate Criteria Expression (eq)
  33. Hibernate Criteria Expression (lt)
  34. Hibernate Criteria Expression (le)
  35. Hibernate Criteria Expression (gt)
  36. Hibernate Criteria Expression (ge)
  37. Hibernate Criteria Expression (and)
  38. Hibernate Criteria Expression (or)
  39. Hibernate Projections (rowCount or countDistinct)
  40. Hibernate Projection Count