[스프링부트/웹 애플리케이션 개발]H2 데이터베이스 설치, JPA와 DB 설정, 동작확인

- 저번에 이미 설치 완료

인프런 스프링 입문 08 / 스프링 DB 접근, H2, JDBC

 

 

 

 

---

 

package jpabook.jpashop;
import lombok.Getter;
import lombok.Setter;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
@Getter @Setter
public class Member {

    @Id @GeneratedValue
    private Long id;
    private String username;

}

package jpabook.jpashop;
import org.springframework.stereotype.Repository;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

@Repository
public class MemberRepository {

    @PersistenceContext
    private EntityManager em;
    //스프링부트에서는 EntityManager 생성 자동으로 해줌

    public Long save(Member member) {
        em.persist(member);
        return member.getId();
    }

    public Member find(Long id) {
        return em.find(Member.class, id);
    }

}

 

- ctrl + shift + T > create new test

 

- build.gradle 코드 추가

test {
	useJUnitPlatform()
}

 

-application.yml 

spring:
  datasource:
    url: jdbc:h2:tcp://localhost/~/jpashop
    username: sa
    password:
    driver-class-name: org.h2.Driver

  jpa:
    hibernate:
      ddl-auto: create
    properties:
      hibernate:
#        show_sql: true
        format_sql: true

logging:
  level:
    org.hibernate.SQL: debug

 

- test 

package jpabook.jpashop;

import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.transaction.annotation.Transactional;

@RunWith(SpringRunner.class)
@SpringBootTest
class MemberRepositoryTest {

    @Autowired MemberRepository memberRepository;

    @Test
    @Transactional
    public void testMember() throws Exception {
        //given
        Member member = new Member();
        member.setUsername("memberA");

        //when
        Long saveId = memberRepository.save(member);
        Member findMember = memberRepository.find(saveId);

        //then
        Assertions.assertThat(findMember.getId()).isEqualTo(member.getId());
        Assertions.assertThat(findMember.getUsername()).isEqualTo(member.getUsername());
    }
}

 

- test 성공, 자동으로 table 생성

 

- H2 연결 확인

    - JDBC URL 과 application.yml에 spring.datasource.url 일치 확인하고 연결

    - member 테이블 생성되어 있음

    - member 테이블에 행 없음

        > test에 transactional 어노테이션은 테스트가 끝나면 롤백

        > o.s.t.c.transaction.TransactionContext   : Rolled back transaction for test:

 

    - 만약 test에 transaction의 rollback을 하지 않고 확인하고 싶다면?

        > @Transactional 어노테이션 밑에 @Rollback(flase) 어노테이션 추가

    @Test
    @Transactional
    @Rollback(false)
    public void testMember() throws Exception {
        //given
        Member member = new Member();
        member.setUsername("memberA");

        //when
        Long saveId = memberRepository.save(member);
        Member findMember = memberRepository.find(saveId);

        //then
        Assertions.assertThat(findMember.getId()).isEqualTo(member.getId());
        Assertions.assertThat(findMember.getUsername()).isEqualTo(member.getUsername());

    }

 

- 추가

Assertions.assertThat(findMember).isEqualTo(member);
        //System.out.println("findMember == member: " + (findMember == member));
        //findMember == member: true
        //같은 transaction 안에서 저장하면 영속성 context가 같음, 같은 영속성 context 안에서는 식별자가 같으면 같은 entity

 

- 쿼리 파라미터 로그 남기기

1) application.yml 코드 추가

logging:
  level:
    org.hibernate.SQL: debug
    org.hibernate.type: trace

2) 외부 라이브러리 (p6spy) 사용 ( https://github.com/gavlyukovskiy/spring-boot-data-source-decorator )

    > 개발 단계에서는 사용 가능하지만, 운영/배포할 때는 성능 테스트하고 사용해야 함

- build.gradle 코드 추가

implementation 'com.github.gavlyukovskiy:p6spy-spring-boot-starter:1.5.6'