인프런 커뮤니티 질문&답변

안녕하세요 강의 수강 후 활용해서 프로젝트를 진행중인데, 영속성 전이 관련해서 질문이 있습니다.

강의 내용처럼 Order에 있는 member에 다음과 같은 설정을 하면

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name="member_id")
private Member memberId;

object references an unsaved transient instance - save the transient instance before flushing에러가 발생합니다.

그래서 다음과 같이 영속성 전이 설정을 하면 에러는 안뜨지만 같은 멤버가 두번씩 저장되는 문제가 발생합니다.

@ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.PERSIST)
@JoinColumn(name="member_id")
private Member memberId;

해당 Order가 Create되면서 Member테이블에 member가 저장되는데 이미 해당 멤버는 db에 저장되어있는 상황. (회원가입하면서 멤버가 저장되어있었음)

ㄴ test05가 두번 저장되어있음

강의 코드는 Order에 영속성 전이 코드를 넣지 않아도 되던데 해당 에러를 발생시키지 않으려면 어떻게 해야할까요?

Member 엔티티와 Order 엔티티 코드 입니다.

@Entity
@Table(name = "ORDERS")
@NoArgsConstructor
@Getter
public class Order {

   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   @Column(name = "order_id")
   private Long id;

   @ManyToOne(fetch = FetchType.LAZY)
   @JoinColumn(name="member_id")
   private Member memberId;

   @Column(name = "post_id")
   private Long postId;

   @Embedded
   private Point price;

   @Column(name="order_at")
   private Timestamp orderAt;

   public static Order of(Member member, Long postId, Point price){
      Order order = new Order();
      order.setMember(member);
      order.postId = postId;
      order.price = price;
      return order;
   }
   public void setMember(Member member){
      this.memberId = member;
      member.getOrders().add(this);
   }

@Entity
@Table(name = "member")
@Getter
@Setter
@NoArgsConstructor
@SQLDelete(sql = "UPDATE member SET deleted_at = NOW() where id = ?")
@Where(clause = "deleted_at is NULL")
public class Member {

   @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
   private Long id;

   @Column(name = "member_id")
   private String memberId;

   private String password;

   @Column(name = "member_name")
   private String memberName;

   private String email;

   @Column(name = "role")
   @Enumerated(EnumType.STRING)
   private MemberRole role = MemberRole.USER;

   @OneToMany(mappedBy = "memberId")
   private List<Order> orders = new ArrayList<Order>();

   public static Member of(String memberId, String password, String memberName, String email){
      Member member = new Member();
      member.setMemberId(memberId);
      member.setPassword(password);
      member.setMemberName(memberName);
      member.setEmail(email);
      return member;
   }

   public static Member of(MemberDto dto){
      Member member = new Member();
      member.setMemberId(dto.getMemberId());
      member.setPassword(dto.getPassword());
      member.setMemberName(dto.getMemberName());
      member.setEmail(dto.getEmail());
      member.setRole(dto.getRole());
      return member;
   }