엔티티 직접 사용

1. 엔티티 직접 사용 - 기본키 값

• JPQL에서 엔티티를 직접 사용할 경우 SQL에서 해당 엔티티의 PK를 사용함

			//엔티티 직접 사용
 			String query1 = "select m from Member m where m = :member";
            Member res1 = em.createQuery(query1, Member.class)
                    .setParameter("member", member1)
                    .getSingleResult();

            System.out.println("member = " + res1);
            
            //엔티티의 아이디를 사용
            String query2 = "select m from Member m where m.Id = :memberId";
            Member res2 = em.createQuery(query2, Member.class)
                    .setParameter("memberId", member1.getId())
                    .getSingleResult();

            System.out.println("member = " + res2);

• 실행쿼리(where절에서 PK를 사용)

Hibernate: 
    /* select
        m 
    from
        Member m 
    where
        m = :member */ select
            member0_.Id as id1_0_,
            member0_.age as age2_0_,
            member0_.TEAM_ID as team_id5_0_,
            member0_.type as type3_0_,
            member0_.username as username4_0_ 
        from
            Member member0_ 
        where
            member0_.Id=?
member = Member{Id=3, username='회원1', age=0}
Hibernate: 
    /* select
        m 
    from
        Member m 
    where
        m.Id = :memberId */ select
            member0_.Id as id1_0_,
            member0_.age as age2_0_,
            member0_.TEAM_ID as team_id5_0_,
            member0_.type as type3_0_,
            member0_.username as username4_0_ 
        from
            Member member0_ 
        where
            member0_.Id=?
member = Member{Id=3, username='회원1', age=0}

2. 엔티티 직접 사용 - 기본키 값

			//엔티티 직접 사용
 			String query3 = "select m from Member m where m.team = :team";
            List<Member> res3 = em.createQuery(query3, Member.class)
                    .setParameter("team", teamA)
                    .getResultList();

            for (Member member : res3) {
                System.out.println("team's member = " + member);
            }
            
            //엔티티의 아이디를 사용
            String query4 = "select m from Member m where m.team.Id = :teamId";
            List<Member> res4 = em.createQuery(query4, Member.class)
                    .setParameter("teamId", teamA.getId())
                    .getResultList();

            for (Member member : res4) {
                System.out.println("team's member = " + member);
            }

• 실행쿼리(where절에서 PK를 사용)

Hibernate: 
    /* select
        m 
    from
        Member m 
    where
        m.team = :team */ select
            member0_.Id as id1_0_,
            member0_.age as age2_0_,
            member0_.TEAM_ID as team_id5_0_,
            member0_.type as type3_0_,
            member0_.username as username4_0_ 
        from
            Member member0_ 
        where
            member0_.TEAM_ID=?
team's member = Member{Id=3, username='회원1', age=0}
team's member = Member{Id=4, username='회원2', age=0}
Hibernate: 
    /* select
        m 
    from
        Member m 
    where
        m.team.Id = :teamId */ select
            member0_.Id as id1_0_,
            member0_.age as age2_0_,
            member0_.TEAM_ID as team_id5_0_,
            member0_.type as type3_0_,
            member0_.username as username4_0_ 
        from
            Member member0_ 
        where
            member0_.TEAM_ID=?
team's member = Member{Id=3, username='회원1', age=0}
team's member = Member{Id=4, username='회원2', age=0}