Learn Native Queries in JPA.
Learn Native Queries in JPA.In this section, you will know about the jpa native queries and how to use native query in your JPA application.
JPA Native Queries: JPA native query executes plain SQL queries. JPA Native queries have the following properties:
For jpa native query application, you need develop the following artifacts:
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: JPANativeQuery.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 JPANativeQuery { /** * @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.createNativeQuery("SELECT sname FROM Student"); List stList=query.getResultList(); Iterator stIterator=stList.iterator(); while(stIterator.hasNext()){ System.out.print("sname:"+stIterator.next()); 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 sname FROM Student sname:Vinod sname:Ravi sname:Suman
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