์ค์์ ์ํ EntityManager(์์์ฑ ์ปจํ ์คํธ)์ ์ฌ๋ ค์ ธ ์๋ ๊ฐ์ฒด๋ฅผ ๋ด๋ฆฌ๋ ๊ฒ ๋์ด์ JPA๊ฐ ๊ด๋ฆฌํ์ง ์๊ฒ ๋ค๋ ๋ป์ ๋๋ค. Method EntityManager.detach() EntityManager.clear() EntityManager.close() Code EntityManagerFactory emf = Persistence.createEntityManagerFactory("hello"); EntityManager em = emf.createEntityManager(); EntityTransaction tx = em.getTransaction(); tx.begin(); try { User user = em.find(User.class, 1L); user.setName("AAAA"); em..