Mini-Project - Java Full Stack Developer - JPA_FP Hands-On Solutions

 Mini-Project - Java Full Stack Developer - JPA_FP Hands-On 

The Course Id is 63715.

1. JPADemo.java

package frescojpa;

import javax.persistence.*;

import frescojpa.Student;

import java.util.*;

public class JPADemo {

  public static void main(String[] args) {

  

        EntityManagerFactory emf = Persistence.createEntityManagerFactory("$objectdb/students.odb");  //creating an entitymanagerfactory instance with the given database

        EntityManager em=emf.createEntityManager();  //enitity manager object creation

          

        em.getTransaction().begin();  //starting the transactions

          

        Student s1=new Student();             //creating 3 student objects

        Student s2=new Student();

        Student s3=new Student(); 

        

        s1.setStudentName("Ramesh"); //setting the names of 3 students as given in question

        s2.setStudentName("Ali");

        s3.setStudentName("John");

          

        em.persist(s1);  //storing them into database

        em.persist(s2);  

        em.persist(s3);    

        em.getTransaction().commit(); //committing the transactions

        List<Student> students= em.createQuery("Select st from Student st").getResultList(); //fetching the students data from database

        //System.out.print("size is:"+students.size());

        for(int i=0;i<students.size();i++){

        System.out.println(students.get(i).studentName+"'s roll number is "+students.get(i).studentRollNumber);

        }

  }

}

2. Student.java

package frescojpa;

import java.io.Serializable;

import javax.persistence.*;

@Entity  //defining student class as the entity class

public class Student implements Serializable {

  

  @Id

  @GeneratedValue(strategy=GenerationType.AUTO) // primary key generation as auto generated

  int studentRollNumber; 

  String studentName;

  Student(){ //default constructor

    

  }

  Student(int studentRollNumber,String studentName){ //parameterized constructor

    this.studentName = studentName;

    this.studentRollNumber=studentRollNumber;

  }

//getters and setters

  public String getStudentName() {

    return studentName;

  }

  public void setStudentName(String studentName) {

    this.studentName = studentName;

  }

  public int getStudentRollNumber() {

    return studentRollNumber;

  }

  public void setStudentRollNumber(int studentRollNumber) {

    this.studentRollNumber = studentRollNumber;

  }

}