[JPA] JPQL- 기본 쿼리문 예시

[JPQL] 쿼리문 예시]

 

1. entity타입을 반환

List<Member> result = em.createQuery("select m from Member as m", Member.class).getResultList();

 

2. 참조하는 entity를 반환 (join)

List<Team> result = em.createQuery("select t from Member as m join m.team as t", Team.class).getResultList();

 

3. entity가 가지고 있는 값타입을 반환

List<Adress> result = em.createQuery("select m.Adress from Member as m", Adress.class).getResultList();

 

4. entity가 가지고 있는 타입이 다른 속성 여러개를 반환 (DTO 사용)

List<MemberDTO> result = em.createQuery("select new jpql.MemberDTO(m.username, m.age) from Member as m", MemberDTO.class).getResultList();