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 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 HibernateHQLCountFunctions {
/**
*
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Session sess = null;
int count = 0;
try {
SessionFactory fact = new
Configuration().configure()
.buildSessionFactory();
sess = fact.openSession();
String SQL_QUERY = "select
count(*)from Insurance insurance group by
insurance.lngInsuranceId";
Query query =
sess.createQuery(SQL_QUERY);
for (Iterator it
= query.iterate(); it.hasNext();) {
it.next();
count++;
}
System.out.println("
Total rows: " + count);
sess.close();
}
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 count(*) as col_0_0_ from insurance insurance0_ group
by insurance0_.ID
Total rows: 6
|
|
Del.icio.us
Digg
Google
Spurl
Blink
Furl
Simpy
Y! MyWeb
