Querydsl 11 - 순수 JPA 리포지토리와 Querydsl, 동적쿼리 Builder

순수 JPA와 Querydsl

• 순수 JPA 리퍼지토리와 Querydsl

• 동적쿼리 Builder 사용

• 동적쿼리 Where 사용

• 조회 API 컨트롤러 개발

 

1. 순수 JPA리퍼지토리와 Querydsl

순수 JPA를 사용한 리퍼지토리를 만들고, 테스트를 해본 뒤, Querydsl로 바꾸면서 둘을 비교해보자.

먼저 순수 JPA 리퍼지토리는 아래와 같다.

@Repository
public class MemberJpaReposiotory {
    private final EntityManager em;
    private final JPAQueryFactory queryFactory;

    public MemberJpaReposiotory(EntityManager em) {
        this.em = em;
        this.queryFactory = new JPAQueryFactory(em);
    }

    public void save(Member member) {
        em.persist(member);
    }

    public Optional<Member> findById(Long id) {
        Member findMember = em.find(Member.class, id);
        return Optional.ofNullable(findMember);
    }

    public List<Member> findAll() {
        return em.createQuery("select m from Member m", Member.class).getResultList();
    }

    public List<Member> findByUsername(String username) {
        return em.createQuery("select m from Member m where m.username = :username", Member.class)
                .setParameter("username", username)
                .getResultList();
    }
}

이를 테스트해보자.

@Transactional
@SpringBootTest
class MemberJpaReposiotoryTest {

    @Autowired EntityManager em;
    @Autowired MemberJpaReposiotory repository;


    @Test
    void save() {
        repository.save(new Member("member1", 10));
    }

    @Test
    void findById() {
        Member member = new Member("member1", 10);
        repository.save(member);
        Member findMember = repository.findById(member.getId()).get();
        Assertions.assertThat(member.getId()).isEqualTo(findMember.getId());
        Assertions.assertThat(member.getUsername()).isEqualTo(findMember.getUsername());
        Assertions.assertThat(member).isEqualTo(findMember);
    }

    @Test
    void findAll() {
        Member member1 = new Member("member1", 10);
        Member member2 = new Member("member2", 10);
        Member member3 = new Member("member3", 10);
        repository.save(member1);
        repository.save(member2);
        repository.save(member3);

        List<Member> result = repository.findAll();
        Assertions.assertThat(result).contains(member1, member2, member3);
    }


    @Test
    void findByUsername() {
        Member member1 = new Member("member1", 10);
        repository.save(member1);
        List<Member> result = repository.findByUsername(member1.getUsername());
        Member findMember = result.get(0);
        Assertions.assertThat(findMember).isEqualTo(member1);
    }
}

 

위의 테스트는 물론 성공한다.

 

순수 JPA 리퍼지토리의  findAll, findByUsername을 Querydsl을 사용하여 바꿔보자.

public List<Member> findAll() {
    return em.createQuery("select m from Member m", Member.class).getResultList();
}
/*Querydsl*/
public List<Member> findAll_Querydsl(){
    return queryFactory.selectFrom(member).fetch();
}

public List<Member> findByUsername(String username) {
    return em.createQuery("select m from Member m where m.username = :username", Member.class)
            .setParameter("username", username)
            .getResultList();
}
/*Querydsl*/
public List<Member> findByUsername_Querydsl(String username){
    return queryFactory.selectFrom(member).where(member.username.eq(username)).fetch();
}

자바 코드를 사용하는 Querydsl이 훨씬 간편하고 가독성에도 좋은 것을 알 수 있다.

 

이제 이를 테스트해보자.

@Transactional
@SpringBootTest
class MemberJpaReposiotoryTest {

    @Autowired EntityManager em;
    @Autowired MemberJpaReposiotory repository;

    @Test
    void findAll() {
        Member member1 = new Member("member1", 10);
        Member member2 = new Member("member2", 10);
        Member member3 = new Member("member3", 10);
        repository.save(member1);
        repository.save(member2);
        repository.save(member3);

        List<Member> result = repository.findAll();
        Assertions.assertThat(result).contains(member1, member2, member3);
    }
    
    @Test
    void findAll_Querydsl() {
        Member member1 = new Member("member1", 10);
        Member member2 = new Member("member2", 10);
        Member member3 = new Member("member3", 10);
        repository.save(member1);
        repository.save(member2);
        repository.save(member3);

        List<Member> result = repository.findAll_Querydsl();
        Assertions.assertThat(result).contains(member1, member2, member3);
    }

    @Test
    void findByUsername() {
        Member member1 = new Member("member1", 10);
        repository.save(member1);
        List<Member> result = repository.findByUsername(member1.getUsername());
        Member findMember = result.get(0);
        Assertions.assertThat(findMember).isEqualTo(member1);
    }

    @Test
    void findByUsername_Querydsl() {
        Member member1 = new Member("member1", 10);
        repository.save(member1);
        List<Member> result = repository.findByUsername_Querydsl(member1.getUsername());
        Member findMember = result.get(0);
        Assertions.assertThat(findMember).isEqualTo(member1);
    }
}

해당 테스트도 물론 성공한다.

 

 

 

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2. 동적쿼리 Builder 사용

 

동적쿼리Builder에 Dto조회를 적용하여 성능을 최적화해보자.

dto는 Member정보와 Team정보를 동시 조회할 것이다. 하여 MemberTeamDto를 만들고 compileQuerydsl을 하여 QMemberTeamDto를 만든다.

@Data
public class MemberTeamDto {

    private Long memberId;
    private String username;
    private int age;
    private Long teamId;
    private String teamName;

    @QueryProjection
    public MemberTeamDto(Long memberId, String username, int age, Long teamId, String teamName) {
        this.memberId = memberId;
        this.username = username;
        this.age = age;
        this.teamId = teamId;
        this.teamName = teamName;
    }
}

 

그리고 동적쿼리의 Condition을 위한 MemberSearchCondition을 만든다.

@Data
public class MemberSearchCondition {
    // 회원명, 팀명, 나이(ageGoe, ageLoe)
    private String username;
    private String teamName;
    private Integer ageGoe;
    private Integer ageLoe;
}

 

 

이제 리퍼지토리에 메서드를 만들어보자.

    public List<MemberTeamDto> searchByBuilder(MemberSearchCondition condition) {

        BooleanBuilder builder = new BooleanBuilder();
        if (StringUtils.hasText(condition.getUsername()))
            builder.and(member.username.eq(condition.getUsername()));

        if (StringUtils.hasText(condition.getTeamName()))
            builder.and(team.name.eq(condition.getTeamName()));

        if (condition.getAgeGoe() != null)
            builder.and(member.age.goe(condition.getAgeGoe()));

        if (condition.getAgeLoe() != null)
            builder.and(member.age.loe(condition.getAgeLoe()));


        return queryFactory
                .select(new QMemberTeamDto(
                        member.id,
                        member.username,
                        member.age,
                        team.id,
                        team.name
                ))
                .from(member)
                .leftJoin(member.team, team)
                .where(builder) /* where 인자에 builder */
                .fetch();
    }

StringUtils.hasText메서드는 빈 문자열과 null을 확인해준다.

 

이제 이를 사용하는 테스트를 보자.

@Test
public void searchTest(){
    Team teamA = new Team("teamA");
    Team teamB = new Team("teamB");
    em.persist(teamA);
    em.persist(teamB);

    Member member1 = new Member("member1", 10, teamA);
    Member member2 = new Member("member2", 20, teamA);
    Member member3 = new Member("member3", 10, teamB);
    Member member4 = new Member("member4", 20, teamB);
    Member member5 = new Member("member5", 55, teamB);
    em.persist(member5);
    em.persist(member1);
    em.persist(member2);
    em.persist(member3);
    em.persist(member4);

    // -- 컨티션 --//
    MemberSearchCondition condition = new MemberSearchCondition();
    condition.setAgeGoe(15);
    condition.setAgeLoe(35); // -> 15~35살
    condition.setTeamName("teamB"); // teamName은 teamB이어야 한다.
    //username 컨디션은 추가하지 않음. 즉 username은 어찌되어도 상관없다는 것이다.
    // -----------

    List<MemberTeamDto> result = repository.searchByBuilder(condition);
    assertThat(result.size()).isEqualTo(1);
    assertThat(result.get(0).getUsername()).isEqualTo("member4");
}

해당 테스트는 성공한다.

 

 

다음 포스트에서

• 동적쿼리 Where 사용

• 조회 API 컨트롤러 개발

에 대해 알아보자.

 

 

 

 

 

 

김영한님의 인프런 강의와 PDF를 바탕으로 정리하였습니다.