ProductSectorAddTest.java

package com.test.jpa;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.Query;

public class ProductSectorAddTest {

	public static void main(String[] args) {

		EntityManagerFactory factory = Persistence.createEntityManagerFactory("JPATest");

		EntityManager entityManager = factory.createEntityManager();

		Query query = entityManager.createQuery("select p from Product p where p.name='Laptop'");

		Product product = (Product)query.getSingleResult();
		
		entityManager.getTransaction().begin();
		
		Sector sector=new Sector();
		sector.setId(1);
		sector.setName("Elektronik");
		
		product.setSector(sector);
		
		entityManager.persist(product);
		
		entityManager.getTransaction().commit();

		entityManager.close();

		factory.close();

	}

}