<!DOCTYPE hibernate-configuration PUBLIC
 "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
 "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
 <session-factory>
  <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
  <property name="connection.url">jdbc:oracle:thin:@localhost:1521/orcl</property>
  <property name="connection.username">scott</property>
  <property name="connection.password">tiger</property>
  <property name="dialect">org.hibernate.dialect.Oracle9Dialect</property>
  <property name="hibernate.current_session_context_class">thread</property>
 </session-factory>
</hibernate-configuration>

package data;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.EntityResult;
import javax.persistence.FieldResult;
import javax.persistence.Id;
import javax.persistence.NamedNativeQuery;
import javax.persistence.SqlResultSetMapping;

@Entity
@SqlResultSetMapping(name = "implicit", entities = @EntityResult(entityClass = data.Employee.class))
@NamedNativeQuery(name = "implicitSample", query = "select e.empno empNumber, e.ename empName, e.job empJob, e.sal empSalary, salg.grade empGrade from emp e, salgrade salg where e.sal between salg.losal and salg.HISAL", resultSetMapping = "implicit")
//@SqlResultSetMapping(name = "explicit", entities = { @EntityResult(entityClass = data.Employee.class, fields = { 
//    @FieldResult(name = "empNumber", column = "empno"), 
//    @FieldResult(name = "empName", column = "ename"),
//    @FieldResult(name = "empJob", column = "job"), 
//    @FieldResult(name = "empSalary", column = "sal"), 
//    @FieldResult(name = "empGrade", column = "grade") }) })
//@NamedNativeQuery(name = "implicitSample", 
//    query = "select e.empno empno, e.ename ename, e.job job, e.sal sal, salg.grade grade from emp e, salgrade salg where e.sal between salg.losal and salg.HISAL", resultSetMapping = "explicit")
public class Employee {

 private String empNumber;

 private String empName;

 private String empJob;

 private Double empSalary;

 private int empGrade;

 @Column
 @Id
 public int getEmpGrade() {
   return empGrade;
 }

 public void setEmpGrade(int empGrade) {
   this.empGrade = empGrade;
 }

 @Column
 public String getEmpJob() {
   return empJob;
 }

 public void setEmpJob(String empJob) {
   this.empJob = empJob;
 }

 @Column
 public String getEmpName() {
   return empName;
 }

 public void setEmpName(String empName) {
   this.empName = empName;
 }

 @Column
 public String getEmpNumber() {
   return empNumber;
 }

 public void setEmpNumber(String empNumber) {
   this.empNumber = empNumber;
 }

 @Column
 public Double getEmpSalary() {
   return empSalary;
 }

 public void setEmpSalary(Double empSalary) {
   this.empSalary = empSalary;
 }

}

• The implitic mapping (the uncommented @NamedNativeQuery and @SqlResultSetMapping declarations are used for implicitly mapping the ResultSet to the entity class. Note that the SQL column names match the field names in the class. If the names do not match then you can set the name attribute of the @Column annotation to the column name in the query.
• The commented @NamedNativeQuery and the @SqlResultSetMapping declarations explicitly map the fields to the columns. This will come in handy when using joins and composite keys etc.
• Note the package definitions refer to javax.persistence and not the hibernate packages. If the packages are not declared properly, you will most likely end up with some exceptions like the following

  org.hibernate.hql.ast.QuerySyntaxException: Employee is not mapped.

  While there are other causes for this exception, the package declarations did cause a little trouble for me.

import java.util.List;

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

import data.Employee;

public class Client {

 public static void main(String[] args) {
   Configuration config = new AnnotationConfiguration().addAnnotatedClass(Employee.class).configure();

   SessionFactory sessionFactory = config.buildSessionFactory();
   Session session = sessionFactory.getCurrentSession();

   List result = null;
   try {
     session.beginTransaction();

     result = session.getNamedQuery("implicitSample").list();
     System.out.println("Result size : " + result.size());
     session.getTransaction().commit();
   } catch (Exception e) {
     e.printStackTrace();
   }
   System.out.println(result.size());
 }

}

hibernate3.jar
commons-collections-2.1.1.jar
antlr-2.7.6.jar
commons-logging-1.0.4.jar
hibernate-annotations.jar
ejb3-persistence.jar
hibernate-commons-annotations.jar
dom4j-1.6.1.jar
ojdbc14.jar
jta.jar
log4j-1.2.11.jar
xerces-2.6.2.jar
xml-apis.jar
cglib-2.1.3.jar
asm.jar