Hibernate Query Language-count

Hibernate Query Language-count(Aggregate function)
Creating DataBase using Mysql


DataBase Name: Navalady

Table Name: Student

Open MYSQL command line Client


Step 1:

Create Database named as Navalady.

Syntax:

mysql > create Database Name;

mysql > create Navalady;

Step 2:

To use Created Database. We use the following statement.

Syntax:

mysql > use Database Name;

mysql > use Navalady;

Step 3:

Create Table named as Student.

Mysql > create table table_name(field_name datatypes,filed_name datatypes….);

Mysql > create table Student(stuname varchar(40),stuno int(20),tamil int(20),English int(20),maths int(20), science int(20),socialscience int(20),primary key(stuno));

Step 4:

Insert the records into Student table.

We have to insert five records.

Hibernate Query Language-Aggregate function-count.

There are many aggregate function available in hibernate. Such as count, sum, max, min etc,

Use:

            Sometimes we want to get number of rows. At that time we use count() function to get total number of rows depending upon condition.

Example:

            Already we have created database as Navalady and table name is Student.

            Now we have to get how many students get hundred marks in mathematics.

Query is select count(*) from Student where maths=”100”;

Procedure:

Note:
· Already we have created project named as HibernateProject.· Also we have created Folder for storing jsp and Hibernate files.


Step 1:

            Create Hibernate Reverse Engineering wizard

Step 2:

             Create HibernateUtil.java

Step 3:
             
               Create POJO class and mapping files

Step 4: 

                 Create jsp file named as CountExam

Include following coding into CountExam

< %@page contentType="text/html" pageEncoding="UTF-8"% >
< !DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
http://www.w3.org/TR/html4/loose.dtd >
< %@page import="org.hibernate.SessionFactory" % >
< %@page import="org.hibernate.Session" % >
< %@page import="org.hibernate.cfg.Configuration" % >
< %@page import="org.hibernate.*" % >
< %@page import="java.util.*" % >
< %@page import="Hiber.Student" % >
< html >
< head >
< title > Hibernate count(aggregate function)Example < /title >
< /head >
< body >
< %

try
{
SessionFactory sessionFactory=new Configuration().configure().buildSessionFactory();
Session s=sessionFactory.openSession();
String sql="select count(*) from Student student where maths=100";
Query query=s.createQuery(sql);
Iterator it=query.iterate();

while(it.hasNext())
{
out.println("Total Studnet get 100 in maths "+it.next());
}
s.close();
}
catch(Exception e)
{
out.println(e);
}
% >
< /body >
< /html >

OUTPUT:

The output is 0.

Because nobody get hundreds in mathematic subject.

Insert new records into the student table in navalady database;

Mysql > insert into Student values(‘Mahinda’,7,66,77,100,100,100);

Mysql > insert into Student values(‘Maahi’,8,66,77,100,100,100);

And Run the CountExam.jsp again.