From 3d4ccecf46f75df53f9044675a6924ecc9d19bb5 Mon Sep 17 00:00:00 2001
From: haerong22 <haerong22@naver.com>
Date: Mon, 6 Feb 2023 03:07:50 +0900
Subject: [PATCH] #30 jpa basic: jpql - bulk

---
 .../main/java/com/hello/jpa/query/Bulk.java   | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 hello-jpa/src/main/java/com/hello/jpa/query/Bulk.java

diff --git a/hello-jpa/src/main/java/com/hello/jpa/query/Bulk.java b/hello-jpa/src/main/java/com/hello/jpa/query/Bulk.java
new file mode 100644
index 00000000..5e155092
--- /dev/null
+++ b/hello-jpa/src/main/java/com/hello/jpa/query/Bulk.java
@@ -0,0 +1,69 @@
+package com.hello.jpa.query;
+
+import com.hello.jpa.query.entity.Member;
+import com.hello.jpa.query.entity.Team;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.EntityTransaction;
+import javax.persistence.Persistence;
+
+public class Bulk {
+
+    public static void main(String[] args) {
+        EntityManagerFactory emf = Persistence.createEntityManagerFactory("hello");
+
+        EntityManager em = emf.createEntityManager();
+
+        EntityTransaction tx = em.getTransaction();
+        tx.begin();
+
+        try {
+            Team team = new Team();
+            team.setName("team1");
+            em.persist(team);
+
+            Team team2 = new Team();
+            team2.setName("team2");
+            em.persist(team2);
+
+            Member member = new Member();
+            member.setName("member1");
+            member.setTeam(team);
+            em.persist(member);
+
+            Member member2 = new Member();
+            member2.setName("member2");
+            member2.setTeam(team);
+            em.persist(member2);
+
+            Member member3 = new Member();
+            member3.setName("member3");
+            member3.setTeam(team2);
+            em.persist(member3);
+
+            // flush 자동 호출
+            int resultCount = em.createQuery("update Member m set m.age = 20")
+                    .executeUpdate();
+
+            System.out.println("resultCount = " + resultCount);
+
+            // 영속성 컨텍스트에 남아 있으므로 초기화 해야함
+            Member findMember = em.find(Member.class, member.getId());
+            System.out.println("findMember = " + findMember);
+
+            em.clear();
+            Member findMember2 = em.find(Member.class, member.getId());
+            System.out.println("findMember = " + findMember2);
+
+            tx.commit();
+        } catch (Exception e) {
+            e.printStackTrace();
+            tx.rollback();
+        } finally {
+            em.close();
+        }
+
+        emf.close();
+    }
+}