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JPA setFirstResult Example

                         

In this section, you will learn how to use setFirstResult method in your jpa application. The setFirstResult(N) method is used to skip the first "N"  elements form the result set. Please note that the counting starts from the 0, so if you specify 2 then first 3 records will be skipped.

setFirstResult(int startingPosition): This is the method of Query interface. The setFirstResult method is used to set the position of first result for retrieving the data. It also return  same query instance. 

For this application you need the following files:

  1. Database Table: student
  2. Model Class: Student.java
  3. Main Class: JPASetFirstResult.java

Database Table: student

CREATE TABLE `student` ( 
`id` int(11) NOT NULL auto_increment, 
`sname` varchar(100) NOT NULL, 
`sroll` int(11) NOT NULL, 
`scourse` varchar(10) NOT NULL, 
PRIMARY KEY (`id`) 
)

Model Class: Student.java

/**

*/
package roseindia;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

/**
* @author Administrator
*
*/
@Entity
@Table(name="student")

public class Student {

@Id
@GeneratedValue
private int id;

/**
* @return the id
*/
public int getId() {
return id;
}

/**
* @param id the id to set
*/
public void setId(int id) {
this.id = id;
}

@Column(name="sname", length=100,nullable=false)
private String sname;

/**
* @return the sname
*/
public String getSname() {
return sname;
}

/**
* @param sname the sname to set
*/
public void setSname(String sname) {
this.sname = sname;
}

@Column(name="sroll",nullable=false)
private int sroll;

/**
* @return the sroll
*/
public int getSroll() {
return sroll;
}

/**
* @param sroll the sroll to set
*/
public void setSroll(int sroll) {
this.sroll = sroll;
}

@Column(name="scourse",length=10,nullable=false)
private String scourse;

/**
* @return the scourse
*/
public String getScourse() {
return scourse;
}

/**
* @param scourse the scourse to set
*/
public void setScourse(String scourse) {
this.scourse = scourse;
}

}

Main Class: JPASetFirstResult.java

/**

*

*/

package roseindia;

 

import java.util.Iterator;

import java.util.List;

 

import javax.persistence.EntityManager;

import javax.persistence.EntityManagerFactory;

import javax.persistence.EntityTransaction;

import javax.persistence.Persistence;

import javax.persistence.Query;

 

/**

* @author Administrator

*

*/

public class JPASetFirstResult {

 

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

 

EntityManagerFactory emf=Persistence.createEntityManagerFactory("jpa");

EntityManager em=emf.createEntityManager();

try{

EntityTransaction entr=em.getTransaction();

entr.begin();

Query query=em.createQuery("SELECT st FROM Student st");

query.setFirstResult(2);

List stuList=query.getResultList();

Iterator stuIterator=stuList.iterator();

while(stuIterator.hasNext()){

Student st=(Student)stuIterator.next();

System.out.print("sname:"+st.getSname());

System.out.print("sroll:"+st.getSroll());

System.out.print("scourse:"+st.getSname());

System.out.println();

}

entr.commit();

}

finally{

em.close();

}

}

}

Output:

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

log4j:WARN Please initialize the log4j system properly.

Hibernate: select student0_.id as id0_, student0_.scourse as scourse0_, student0_.sname as sname0_, student0_.sroll as sroll0_ from student student0_

sname:Suman sroll:103 scourse:Suman

sname:Noor sroll:104 scourse:Noor

                         

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