[Fix] Q&A 도메인 타입 정합성 및 조회 성능 개선

backend/src/main/java/com/example/Piroin/project/domain/attendance/repository/AttendanceCodeRepository.java

@@ -5,14 +5,13 @@
 import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
-import org.springframework.stereotype.Repository;
 
 import java.time.LocalDate;
 import java.util.List;
 import java.util.Optional;
 
 
-public interface AttendanceCodeRepository extends JpaRepository<AttendanceCode, Long> {
+public interface AttendanceCodeRepository extends JpaRepository<AttendanceCode, Integer> {
 
     // [추가] 모든 활성화된 코드를 한 번에 만료 처리 (벌크 연산)
     @Modifying
@@ -34,4 +33,3 @@ public interface AttendanceCodeRepository extends JpaRepository<AttendanceCode,
     List<AttendanceCode> findByAttendanceDate(LocalDate attendanceDate);
 }
 
-

backend/src/main/java/com/example/Piroin/project/domain/attendance/repository/AttendanceRepository.java

@@ -1,27 +1,20 @@
 package com.example.Piroin.project.domain.attendance.repository;
 
-import com.example.Piroin.project.domain.attendance.entity.AttendanceCode;
-import com.example.Piroin.project.domain.curriculum.entity.StudySession;
 import com.example.Piroin.project.domain.user.entity.User;
 import com.example.Piroin.project.domain.attendance.entity.Attendance;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
-import org.springframework.stereotype.Repository;
 
 import java.time.LocalDate;
 import java.util.List;
 import java.util.Optional;
 
-public interface AttendanceRepository extends JpaRepository<Attendance, Long> {
+public interface AttendanceRepository extends JpaRepository<Attendance, Integer> {
 
     Optional<Attendance> findById(Integer id);
 
 
-    // 연관관계 필드명이 attendanceCode 라면 내부 ID인 Id를 조합하여 명명
-    Optional<Attendance> findByUserIdAndAttendanceCodeId(Long userId, Long attendanceCodeId);
-
-
     int countByUserAndStatusFalse(User user);
 
     // 1. 특정 출석 코드 ID에 해당하는 결석 데이터 조회

backend/src/main/java/com/example/Piroin/project/domain/attendance/service/AttendanceService.java

@@ -165,7 +165,7 @@ public AttendanceMarkResponse markAttendance(Long userId, String inputCode) {
         // 혹은 조회된 code의 날짜/차수 정보를 기반으로 기존 출석 기록을 찾아야 합니다.
         // (여기서는 이전 답변 시나리오 1인 'attendanceCodeId'로 매핑했다고 가정했을 때의 예시입니다.)
         Attendance attendance = attendanceRepository
-                .findByUserIdAndAttendanceCodeId(userId, Long.valueOf(code.getId()))
+                .findByUserIdAndAttendanceCodeId(userId, code.getId())
                 .orElse(null);
 
         // 해당 사용자와 출석 코드에 대한 출석 기록이 존재하지 않는 경우
@@ -323,4 +323,3 @@ public List<AttendanceStatusRes> findByUserId(Integer userId) {
 
 
 }
-

backend/src/main/java/com/example/Piroin/project/domain/deposit/repository/DepositRepository.java

@@ -7,7 +7,7 @@
 import java.util.List;
 import java.util.Optional;
 
-public interface DepositRepository extends JpaRepository<Deposit, Long> {
+public interface DepositRepository extends JpaRepository<Deposit, Integer> {
     Optional<Deposit> findByUser(User user);
 
     Optional<Deposit> findByUserId(Long userId);

backend/src/main/java/com/example/Piroin/project/domain/question/entity/QuestionAnonymousIdentity.java

@@ -1,6 +1,7 @@
 package com.example.Piroin.project.domain.question.entity;
 
 import com.example.Piroin.project.domain.user.entity.User;
+import com.example.Piroin.project.domain.user.enums.Role;
 import jakarta.persistence.*;
 import lombok.*;
 
@@ -11,12 +12,12 @@
         name = "question_anonymous_identity",
         uniqueConstraints = {
                 @UniqueConstraint(
-                        name = "uq_question_anon_question_user",
+                        name = "uq_question_anonymous_identity_question_user",
                         columnNames = {"question_id", "user_id"}
                 ),
                 @UniqueConstraint(
-                        name = "uq_question_anon_question_no",
-                        columnNames = {"question_id", "anonymous_no"}
+                        name = "uq_question_anonymous_identity_question_role_no",
+                        columnNames = {"question_id", "role", "anonymous_no"}
                 )
         }
 )
@@ -41,7 +42,10 @@ public class QuestionAnonymousIdentity {
     @Column(name = "anonymous_no", nullable = false)
     private Integer anonymousNo;
 
+    @Enumerated(EnumType.STRING)
+    @Column(name = "role", nullable = false)
+    private Role role;
+
     @Column(name = "created_at", nullable = false)
     private LocalDateTime createdAt;
 }
-

backend/src/main/java/com/example/Piroin/project/domain/question/repository/QuestionAnonymousIdentityRepository.java

@@ -8,22 +8,37 @@
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
+import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 
 public interface QuestionAnonymousIdentityRepository extends JpaRepository<QuestionAnonymousIdentity, Long> {
 
     // 해당 질문에서 유저의 익명 번호 조회
     // 용도: 댓글 작성 시 이미 번호가 있는지 확인
     Optional<QuestionAnonymousIdentity> findByQuestionAndUser(Question question, User user);
 
-    // 해당 질문에서 특정 역할(MEMBER/ADMIN)의 익명 번호 수 조회
-    // 용도: 새 익명 번호 발급 시 역할별로 따로 카운트
-    // MEMBER → 익명1, 익명2... / ADMIN → 운영진1, 운영진2...
-    int countByQuestionAndUser_Role(Question question, Role role);
+    // 질문 상세 조회용: 댓글 작성자들의 익명 번호를 한 번에 조회
+    @Query("""
+            SELECT identity
+            FROM QuestionAnonymousIdentity identity
+            JOIN FETCH identity.user
+            WHERE identity.question = :question
+              AND identity.user.id IN :userIds
+            """)
+    List<QuestionAnonymousIdentity> findByQuestionAndUserIds(
+            @Param("question") Question question,
+            @Param("userIds") Set<Long> userIds
+    );
 
-    @Query("SELECT COALESCE(MAX(a.anonymousNo), 0) FROM QuestionAnonymousIdentity a " + "WHERE a.question = :question AND a.user.role = :role")
+    @Query("""
+            SELECT COALESCE(MAX(identity.anonymousNo), 0)
+            FROM QuestionAnonymousIdentity identity
+            WHERE identity.question = :question
+              AND identity.role = :role
+            """)
     int findMaxAnonymousNoByQuestionAndRole(
             @Param("question") Question question,
             @Param("role") Role role
     );
-}
+}

backend/src/main/java/com/example/Piroin/project/domain/question/repository/QuestionCommentRepository.java

@@ -11,11 +11,19 @@
 
 public interface QuestionCommentRepository extends JpaRepository<QuestionComment, Long> {
     /*
-    특정 질문의 삭제되지 않은 최상위 댓글 목록(등록순)
-    parentComment가 null인 것 = 대댓글이 아닌 최상위 댓글
-    용도: 질문 상세 페이지에서 댓글 목록 표시 시
+    질문 상세 조회용 댓글 목록을 한 번에 가져온다.
+    댓글 작성자와 부모 댓글을 함께 로딩해 댓글/대댓글 DTO 조립 중 N+1 조회를 피한다.
     */
-    List<QuestionComment> findByQuestionAndParentCommentIsNullAndDeletedAtIsNullOrderByCreatedAtAsc(Question question);
+    @Query("""
+            SELECT comment
+            FROM QuestionComment comment
+            JOIN FETCH comment.user
+            LEFT JOIN FETCH comment.parentComment
+            WHERE comment.question = :question
+              AND comment.deletedAt IS NULL
+            ORDER BY comment.createdAt ASC, comment.id ASC
+            """)
+    List<QuestionComment> findByQuestionWithUserAndParentComment(@Param("question") Question question);
 
     /*
     질문 목록 미리보기용 최상위 댓글 3개를 질문별로 한 번에 조회한다.
@@ -25,7 +33,7 @@ public interface QuestionCommentRepository extends JpaRepository<QuestionComment
             SELECT ranked.question_id AS "questionId",
                    ranked.id AS "commentId",
                    ranked.user_id AS "userId",
-                   u.role AS "userRole",
+                   COALESCE(qai.role, u.role) AS "userRole",
                    ranked.content AS "content",
                    ranked.image_url AS "imageUrl",
                    ranked.created_at AS "createdAt",
@@ -64,12 +72,6 @@ WHERE qc.question_id IN (:questionIds)
             """)
     List<CommentCountRow> countByQuestionIds(@Param("questionIds") List<Long> questionIds);
 
-    /*
-    특정 댓글의 대댓글 목록(등록순)
-    용도: 댓글 아래 대댓글을 가져올 때
-    */
-    List<QuestionComment> findByParentCommentAndDeletedAtIsNullOrderByCreatedAtAsc(QuestionComment parentComment);
-
     interface PreviewCommentRow {
         Long getQuestionId();
 

backend/src/main/java/com/example/Piroin/project/domain/question/repository/QuestionRepository.java

@@ -2,7 +2,11 @@
 
 import com.example.Piroin.project.domain.curriculum.entity.StudySession;
 import com.example.Piroin.project.domain.question.entity.Question;
+import jakarta.persistence.LockModeType;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 import java.util.List;
 import java.util.Optional;
@@ -19,4 +23,28 @@ public interface QuestionRepository extends JpaRepository<Question, Long> {
     용도: 질문 상세 조회, 수정, 삭제, 좋아요 처리 시
     */
     Optional<Question> findByIdAndDeletedAtIsNull(Long id);
-}
+
+    /*
+    질문 상세 조회용: 질문 작성자를 함께 가져와 상세 DTO 조립 중 추가 조회를 피한다.
+    */
+    @Query("""
+            SELECT question
+            FROM Question question
+            JOIN FETCH question.user
+            WHERE question.id = :id
+              AND question.deletedAt IS NULL
+            """)
+    Optional<Question> findDetailByIdAndDeletedAtIsNull(@Param("id") Long id);
+
+    /*
+    좋아요 카운트 갱신용: 같은 질문에 대한 동시 토글 요청을 직렬화해 likeCount lost update를 방지한다.
+    */
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("""
+            SELECT question
+            FROM Question question
+            WHERE question.id = :id
+              AND question.deletedAt IS NULL
+            """)
+    Optional<Question> findByIdAndDeletedAtIsNullForUpdate(@Param("id") Long id);
+}