Error : org.springframework.dao.InvalidDataAccessApiUsageException: detached entity passed to persist

 

@SpringBootTest
class MemberRepositoryTest {

    @Autowired
    MemberRepository memberRepository; // memberRepository 연결 누가 어떻게 하는 거지?

    @Test
    @Transactional
    public void testMember() throws Exception {
        //given
        Member member = new Member();
        member.setUserName("memberA");
        member.setId(1L);
        //when
        Long saveId = memberRepository.save(member);
        Member findMember = memberRepository.find(saveId);

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

위 코드를 돌리는데

org.springframework.dao.InvalidDataAccessApiUsageException: detached entity passed to persist: jpabook.jpashop.Member; nested exception is org.hibernate.PersistentObjectException: detached entity passed to persist: jpabook.jpashop.Member 

에러가 발생하였다.

@Entity
@Getter @Setter
public class Member {

    @Id @GeneratedValue
    private Long id;
    private String userName;
}

이유는 다음과 같이 @Id @GeneratedValue로 식별자 생성을 데이터 베이스에 맡겼는데 테스트 코드에서 member.setId(1L); 로 기본 키를 직접 할당한 것이 문제였다.