querydsl dto mapping & subquery 질문 남깁니다.

안녕하세요 열심히 수업듣고 따라하고있는 수강생입니다.

먼저 매번 답변주셔서 감사합니다.

질문으로는 dto mapping 에서 @queryprojection 으로 직접 조회를 해야하는 상황입니다.

글 : 채팅방 1 : N

채팅방 : 채팅 1: N

일때

DTO 는

@Data
public class QChatRoomDto {
    private QaType qaApart;
    private String qaContent;
    private String searchPlace;
    private String category;
    private Long chooseMemberIdx; // 채택 / 미채택 기준
    private Long roomIdx;
    private Long otherMemberIdx;
    private String otherMemberNickname;
    private String otherMemberImgDto;
    private int qaCount;
    private String modifiedDate;
    private String recentlyMsg;
    private String recentlyMsgType;
    private Long notReadCount;

    @QueryProjection
    public QChatRoomDto(String qaContent, String searchPlace, String category, Long chooseMemberIdx, Long roomIdx, Long otherMemberIdx, String otherMemberNickname, String otherMemberImgDto, int qaCount, LocalDateTime modifiedDate, String recentlyMsg, String recentlyMsgType, Long notReadCount) {
        this.qaApart = QUESTION;
        this.qaContent = qaContent;
        this.searchPlace = searchPlace;
        this.category = category;
        this.chooseMemberIdx = chooseMemberIdx;
        this.roomIdx = roomIdx;
        this.otherMemberIdx = otherMemberIdx;
        this.otherMemberNickname = otherMemberNickname;
        this.otherMemberImgDto = otherMemberImgDto;
        this.qaCount = qaCount;
        this.modifiedDate = modifiedDate.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
        this.recentlyMsg = recentlyMsg;
        this.recentlyMsgType = recentlyMsgType;
        this.notReadCount = notReadCount;
    }
}

querydsl

public Page<QChatRoomDto> myQuestionChatRoomList(Member questionMember, List<Member> blockMembers, QaStatusType qaStatusType, Pageable pageable) {
    return applyPagination(pageable, contentQuery -> contentQuery
            .selectDistinct(new QQChatRoomDto(
                            qa.content.as("qaContent"),
                            qa.searchPlace.as("searchPlace"),
                            qa.category.name.as("category"),
                            qa.selectMember.idx.as("chooseMemberIdx"),
                            chatRoom.idx.as("roomIdx"),
                            chatRoom.aMember.idx.as("otherMemberIdx"),
                            chatRoom.aMember.nickname.as("otherMemberNickname"),
                            chatRoom.aMember.memberImg.as("otherMemberImgDto"),
                            chatRoom.qMember.qaList.size().as("qaCount"),
                            chatRoom.modifiedDate.as("modifiedDate"),
                            ExpressionUtils.as(
                                    JPAExpressions.select(chat.content)
                                            .from(chat)
                                            .where(chat.chatRoom.eq(chatRoom),
                                                    chat.idx.eq(
                                                            JPAExpressions.select(chat.idx.max())
                                                                    .from(chat))
                                            ), "recentlyMsg")
                            ,
                            ExpressionUtils.as(
                                    JPAExpressions.select(chat.chatType)
                                            .from(chat)
                                            .where(chat.chatRoom.eq(chatRoom),
                                                    chat.idx.eq(
                                                            JPAExpressions.select(chat.idx.max())
                                                                    .from(chat))
                                            ), "recentlyMsgType"),
                            ExpressionUtils.as(
                                    JPAExpressions.select(chat.count())
                                            .from(chat)
                                            .where(chat.chatRoom.eq(chatRoom),
                                                    chat.member.ne(questionMember),
                                                    chat.readMsg.isFalse()), "notReadCount")
                    )
            )
            .from(chatRoom)
            .join(chatRoom.qa, qa)
            .join(chatRoom.aMember, member)
            .where(chatRoom.qMember.eq(questionMember),
                    isQaSelectMember(questionMember, qaStatusType),
                    blockAMembersNotIn(blockMembers),
                    chatRoom.idx.notIn(
                            JPAExpressions.select(chatRoom.idx)
                                    .from(chatRoom)
                                    .where(chatRoom.isLeave.contains("_" + questionMember.getIdx() + "_"))),
                    member.phoneNum.isNotNull()
            )
            .orderBy(chatRoom.modifiedDate.desc()));
}

이렇게 작업을 했습니다. 매우 이상한 쿼리이겠지만 저한텐 이게 최선이었습니다 ㅠ

여기서 궁금한점은 채팅룸 리스트를 뽑아야 하는데

recentlyMsg, recentlyMsgType

채팅 리스트의 최근 데이터를 가지고 오고싶었으나

subQuery에서 limit 1 이 먹히지 않아

저런 괴랄한? 쿼리를 만들어 작동은 되게 만들었습니다.

해서 dto mapping 할때 컬렉션 리스트를 뽑는 다른 방법이 있는지 궁금합니다.

chatRoom.chatlist 를 반환하여 queryprojection에서 가공하려 했지만

에러가 뜨면서 chatList는 반환이 안되어 질문글 남깁니다.

감사합니다.