Hibernate Named Query

Named Query is very useful concept in hibernate. It lets you separate queries from coding section of the application to the mapping xml file(.hbm files).

Hibernate Named Query

Hibernate Named Query

     

Named Query is very useful concept in hibernate. It lets you separate queries from coding section of the application to the mapping xml file(.hbm files). The query is given unique name for the entire application. The application can use the query by using the name of the query. This way the application is able to use the same query multiple times without writing the same query multiple times.

Defining the query in hbm file: (Put query inside â??hibernate-mappingâ?? element, but don't put it before the â??classâ?? element)

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC

"-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

<class name="net.roseindia.hibernate.model.Contact" table="contact">

<id name="id" type="long" column="ID" >

<generator class="increment"/>

</id>

<property name="firstName">

<column name="first_name" />

</property>

<property name="lastName">

<column name="last_name"/>

</property>

</class>

<query name="findContactByFirstName">

<![CDATA[from Contact c where c.firstName = :firstName]]>

</query>

</hibernate-mapping>

 

Calling Named Query in the coding section

You can call the named query with getNamedQuery method which takes the name of the query as parameter.

package net.roseindia.example;

import java.util.List;

import net.roseindia.hibernate.model.Contact;

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

public class NamedQueryExample {
public static void main(String[] args) {
Session session = null;

try{
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
session =sessionFactory.openSession();

Query query = session.getNamedQuery("findContactByFirstName").setString("firstName", "Ravi");
List results = query.list();
System.out.println("No of Results: " + results.size());

}catch(Exception e){
System.out.println(e.getMessage());
}finally{
session.flush();
session.close();

}

}
}

The Structure of the table is as follows:

CREATE TABLE `contact` (
`ID` bigint(20) NOT NULL,
`first_name` varchar(255) default NULL,
`last_name` varchar(255) default NULL,
PRIMARY KEY (`ID`)
)

Download the hibernate application for eclipse.

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