projects200 · dlchdaud123 · Mar 9, 2026 · Feb 13, 2026 · Mar 4, 2026 · Mar 9, 2026
diff --git a/documents/Undabang SQL/Undabang Database DDL.sql b/documents/Undabang SQL/Undabang Database DDL.sql
@@ -25,6 +25,7 @@ DROP TABLE IF EXISTS notification_types;
 DROP TABLE IF EXISTS fcm_tokens;
 
 DROP TABLE IF EXISTS comment_likes;
+DROP TABLE IF EXISTS comment_tags;
 DROP TABLE IF EXISTS comments;
 DROP TABLE IF EXISTS feed_likes;
 DROP TABLE IF EXISTS feed_pictures;
@@ -660,6 +661,17 @@ CREATE TABLE comments
     CONSTRAINT FK_comments_feed FOREIGN KEY (feed_id) REFERENCES feeds (feed_id)
 );
 
+CREATE TABLE comment_tags
+(
+    comment_tag_id         BIGINT   NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT '댓글 태그 식별자',
+    comment_id             BIGINT   NOT NULL,
+    tagged_member_id       CHAR(36) NOT NULL COMMENT '태그된 회원 UUID',
+    comment_tag_created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT FK_comment_tags_comment FOREIGN KEY (comment_id) REFERENCES comments (comment_id),
+    CONSTRAINT FK_comment_tags_member FOREIGN KEY (tagged_member_id) REFERENCES members (member_id)
+);
+
 CREATE TABLE comment_likes
 (
     comment_like_id         BIGINT   NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT '피드 댓글 좋아요 식별자',

diff --git a/src/main/java/com/project200/undabang/comment/dto/record/TaggedMemberRecord.java b/src/main/java/com/project200/undabang/comment/dto/record/TaggedMemberRecord.java
@@ -0,0 +1,8 @@
+package com.project200.undabang.comment.dto.record;
+
+import java.util.UUID;
+
+public record TaggedMemberRecord(
+        UUID memberId,
+        String memberNickname) {
+}
diff --git a/src/main/java/com/project200/undabang/comment/dto/request/CreateCommentRequest.java b/src/main/java/com/project200/undabang/comment/dto/request/CreateCommentRequest.java
@@ -2,7 +2,10 @@
 
 import jakarta.validation.constraints.NotBlank;
 
+import java.util.UUID;
+
 public record CreateCommentRequest(
         @NotBlank(message = "댓글 내용은 필수입니다.") String content,
-        Long parentCommentId) {
+        Long parentCommentId,
+        UUID taggedMemberId) {
 }
diff --git a/src/main/java/com/project200/undabang/comment/dto/response/CommentResponse.java b/src/main/java/com/project200/undabang/comment/dto/response/CommentResponse.java
@@ -1,5 +1,7 @@
 package com.project200.undabang.comment.dto.response;
 
+import com.project200.undabang.comment.dto.record.TaggedMemberRecord;
+
 import java.time.LocalDateTime;
 import java.util.List;
 import java.util.UUID;
@@ -14,5 +16,6 @@ public record CommentResponse(
         Integer likesCount,
         Boolean commentIsLiked,
         LocalDateTime createdAt,
+        TaggedMemberRecord taggedMember,
         List<CommentResponse> children) {
 }
diff --git a/src/main/java/com/project200/undabang/comment/entity/CommentTag.java b/src/main/java/com/project200/undabang/comment/entity/CommentTag.java
@@ -0,0 +1,42 @@
+package com.project200.undabang.comment.entity;
+
+import com.project200.undabang.member.entity.Member;
+import jakarta.persistence.*;
+import lombok.*;
+import org.hibernate.annotations.ColumnDefault;
+
+import java.time.LocalDateTime;
+
+@Getter
+@Builder
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+@Entity
+@Table(name = "comment_tags")
+public class CommentTag {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "comment_tag_id", nullable = false, updatable = false)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY, optional = false)
+    @JoinColumn(name = "comment_id", nullable = false, updatable = false)
+    private Comment comment;
+
+    @ManyToOne(fetch = FetchType.LAZY, optional = false)
+    @JoinColumn(name = "tagged_member_id", nullable = false, updatable = false)
+    private Member taggedMember;
+
+    @Builder.Default
+    @ColumnDefault("CURRENT_TIMESTAMP")
+    @Column(name = "comment_tag_created_at", nullable = false, updatable = false)
+    private LocalDateTime createdAt = LocalDateTime.now();
+
+    public static CommentTag of(Comment comment, Member taggedMember) {
+        return CommentTag.builder()
+                .comment(comment)
+                .taggedMember(taggedMember)
+                .build();
+    }
+}
diff --git a/src/main/java/com/project200/undabang/comment/repository/CommentTagRepository.java b/src/main/java/com/project200/undabang/comment/repository/CommentTagRepository.java
@@ -0,0 +1,7 @@
+package com.project200.undabang.comment.repository;
+
+import com.project200.undabang.comment.entity.CommentTag;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface CommentTagRepository extends JpaRepository<CommentTag, Long> {
+}
diff --git a/src/main/java/com/project200/undabang/comment/repository/impl/CommentRepositoryImpl.java b/src/main/java/com/project200/undabang/comment/repository/impl/CommentRepositoryImpl.java
@@ -1,7 +1,9 @@
 package com.project200.undabang.comment.repository.impl;
 
+import com.project200.undabang.comment.dto.record.TaggedMemberRecord;
 import com.project200.undabang.comment.dto.response.CommentResponse;
 import com.project200.undabang.comment.entity.QComment;
+import com.project200.undabang.comment.entity.QCommentTag;
 import com.project200.undabang.comment.repository.CommentRepositoryCustom;
 import com.project200.undabang.common.entity.QPicture;
 import com.project200.undabang.like.entity.QCommentLike;
@@ -35,6 +37,8 @@ public class CommentRepositoryImpl implements CommentRepositoryCustom {
     private final QPicture picture = QPicture.picture;
     private final QCommentLike commentLike = QCommentLike.commentLike;
     private final QMemberBlock memberBlock = QMemberBlock.memberBlock;
+    private final QCommentTag commentTag = QCommentTag.commentTag;
+    private final QMember taggedMember = new QMember("taggedMember");
 
     @Override
     public List<CommentResponse> findCommentsWithChildrenByFeedId(Long feedId, Member currentMember) {
@@ -50,11 +54,16 @@ public List<CommentResponse> findCommentsWithChildrenByFeedId(Long feedId, Membe
                         comment.likesCount,
                         isCommentLikedExpression(currentMember),
                         comment.createdAt,
+                        Projections.constructor(TaggedMemberRecord.class,
+                                taggedMember.memberId,
+                                taggedMember.memberNickname),
                         Expressions.constant(Collections.<CommentResponse>emptyList())))
                 .from(comment)
                 .leftJoin(comment.member, member)
                 .leftJoin(member.memberPicture, memberPicture)
                 .leftJoin(memberPicture.picture, picture)
+                .leftJoin(commentTag).on(commentTag.comment.eq(comment))
+                .leftJoin(commentTag.taggedMember, taggedMember)
                 .where(
                         comment.feed.id.eq(feedId),
                         comment.parent.isNull(),
@@ -84,11 +93,16 @@ public List<CommentResponse> findCommentsWithChildrenByFeedId(Long feedId, Membe
                         comment.likesCount,
                         isCommentLikedExpression(currentMember),
                         comment.createdAt,
+                        Projections.constructor(TaggedMemberRecord.class,
+                                taggedMember.memberId,
+                                taggedMember.memberNickname),
                         Expressions.constant(Collections.<CommentResponse>emptyList())))
                 .from(comment)
                 .leftJoin(comment.member, member)
                 .leftJoin(member.memberPicture, memberPicture)
                 .leftJoin(memberPicture.picture, picture)
+                .leftJoin(commentTag).on(commentTag.comment.eq(comment))
+                .leftJoin(commentTag.taggedMember, taggedMember)
                 .where(
                         comment.parent.id.in(parentIds),
                         comment.deletedAt.isNull(),
@@ -111,6 +125,7 @@ public List<CommentResponse> findCommentsWithChildrenByFeedId(Long feedId, Membe
                         parent.likesCount(),
                         parent.commentIsLiked(),
                         parent.createdAt(),
+                        parent.taggedMember(),
                         childrenMap.getOrDefault(parent.commentId(), new ArrayList<>())))
                 .collect(Collectors.toList());
     }

diff --git a/src/main/java/com/project200/undabang/comment/service/impl/CommentCommandServiceImpl.java b/src/main/java/com/project200/undabang/comment/service/impl/CommentCommandServiceImpl.java
@@ -3,7 +3,9 @@
 import com.project200.undabang.comment.dto.request.CreateCommentRequest;
 import com.project200.undabang.comment.dto.response.CreateCommentResponse;
 import com.project200.undabang.comment.entity.Comment;
+import com.project200.undabang.comment.entity.CommentTag;
 import com.project200.undabang.comment.repository.CommentRepository;
+import com.project200.undabang.comment.repository.CommentTagRepository;
 import com.project200.undabang.comment.service.CommentCommandService;
 import com.project200.undabang.common.context.UserContextHolder;
 import com.project200.undabang.common.web.exception.CustomException;
@@ -24,6 +26,7 @@
 public class CommentCommandServiceImpl implements CommentCommandService {
 
     private final CommentRepository commentRepository;
+    private final CommentTagRepository commentTagRepository;
     private final FeedRepository feedRepository;
     private final MemberRepository memberRepository;
 
@@ -49,6 +52,14 @@ public CreateCommentResponse createComment(Long feedId, CreateCommentRequest req
         Comment comment = Comment.create(member, feed, parentComment, request);
         Comment savedComment = commentRepository.save(comment);
 
+        // 태그된 멤버가 있으면 CommentTag 생성
+        if (request.taggedMemberId() != null) {
+            Member taggedMember = memberRepository
+                    .findByMemberIdAndMemberDeletedAtNull(request.taggedMemberId())
+                    .orElseThrow(() -> new CustomException(ErrorCode.MEMBER_NOT_FOUND));
+            commentTagRepository.save(CommentTag.of(savedComment, taggedMember));
+        }
+
         // 피드 댓글 수 증가
         feed.incrementCommentsCount();
 

diff --git a/src/main/java/com/project200/undabang/common/web/exception/ErrorCode.java b/src/main/java/com/project200/undabang/common/web/exception/ErrorCode.java
@@ -103,6 +103,9 @@ public enum ErrorCode {
     COMMENT_DELETE_FORBIDDEN(403, "COMMENT_DELETE_FORBIDDEN", "댓글 삭제 권한이 없습니다."),
     COMMENT_PARENT_NOT_FOUND(404, "COMMENT_PARENT_NOT_FOUND", "부모 댓글을 찾을 수 없습니다."),
 
+    // 댓글 태그 관련 에러
+    COMMENT_TAG_NOT_ALLOWED(400, "COMMENT_TAG_NOT_ALLOWED", "대댓글에서만 태그 기능을 사용할 수 있습니다."),
+
     // 피드 관련 에러
     FEED_NOT_FOUND(404, "FEED_NOT_FOUND", "존재하지 않는 피드입니다."),
 

diff --git a/src/test/java/com/project200/undabang/comment/controller/CommentCommandControllerTest.java b/src/test/java/com/project200/undabang/comment/controller/CommentCommandControllerTest.java
@@ -47,7 +47,7 @@ void createComment_success() throws Exception {
             // given
             UUID testMemberId = UUID.randomUUID();
             Long feedId = 1L;
-            CreateCommentRequest request = new CreateCommentRequest("댓글 내용입니다.", null);
+            CreateCommentRequest request = new CreateCommentRequest("댓글 내용입니다.", null, null);
             CreateCommentResponse responseDto = new CreateCommentResponse(1L);
 
             BDDMockito
@@ -69,7 +69,8 @@ void createComment_success() throws Exception {
                                     parameterWithName("feedId").attributes(getTypeFormat(JsonFieldType.NUMBER)).description("댓글을 작성할 피드의 고유 식별자(ID) 입니다.")),
                             requestFields(
                                     fieldWithPath("content").type(JsonFieldType.STRING).description("작성할 댓글의 내용입니다."),
-                                    fieldWithPath("parentCommentId").type(JsonFieldType.NUMBER).description("해당 댓글이 대댓글인 경우, 부모 댓글의 고유 식별자(ID)입니다.").optional()),
+                                    fieldWithPath("parentCommentId").type(JsonFieldType.NUMBER).description("해당 댓글이 대댓글인 경우, 부모 댓글의 고유 식별자(ID)입니다.").optional(),
+                                    fieldWithPath("taggedMemberId").type(JsonFieldType.STRING).description("태그할 멤버의 고유 식별자(ID)입니다.").optional()),
                             responseFields(commonResponseFields(fieldWithPath("data.commentId").type(JsonFieldType.NUMBER).description("작성된 댓글의 고유 식별자(ID) 입니다.")))))
                     .andReturn().getResponse().getContentAsString();
 
@@ -86,7 +87,7 @@ void createReply_success() throws Exception {
             UUID testMemberId = UUID.randomUUID();
             Long feedId = 1L;
             Long parentCommentId = 1L;
-            CreateCommentRequest request = new CreateCommentRequest("대댓글 내용입니다.", parentCommentId);
+            CreateCommentRequest request = new CreateCommentRequest("대댓글 내용입니다.", parentCommentId, null);
             CreateCommentResponse responseDto = new CreateCommentResponse(2L);
 
             BDDMockito
@@ -114,7 +115,7 @@ void createComment_Failed_FeedNotFound() throws Exception {
             // given
             UUID testMemberId = UUID.randomUUID();
             Long feedId = 999L;
-            CreateCommentRequest request = new CreateCommentRequest("댓글 내용입니다.", null);
+            CreateCommentRequest request = new CreateCommentRequest("댓글 내용입니다.", null, null);
 
             BDDMockito
                     .given(commentCommandService.createComment(BDDMockito.eq(feedId),
@@ -141,7 +142,7 @@ void createReply_Failed_ParentNotFound() throws Exception {
             // given
             UUID testMemberId = UUID.randomUUID();
             Long feedId = 1L;
-            CreateCommentRequest request = new CreateCommentRequest("대댓글 내용입니다.", 999L);
+            CreateCommentRequest request = new CreateCommentRequest("대댓글 내용입니다.", 999L, null);
 
             BDDMockito
                     .given(commentCommandService.createComment(BDDMockito.eq(feedId),
@@ -167,7 +168,7 @@ void createReply_Failed_ParentNotFound() throws Exception {
         void createComment_Failed_Not_Having_Token() throws Exception {
             // given
             Long feedId = 1L;
-            CreateCommentRequest request = new CreateCommentRequest("댓글 내용입니다.", null);
+            CreateCommentRequest request = new CreateCommentRequest("댓글 내용입니다.", null, null);
 
             // when & then
             mockMvc.perform(MockMvcRequestBuilders.post("/api/v1/feeds/{feedId}/comments", feedId)
@@ -201,7 +202,8 @@ void deleteComment_success() throws Exception {
                     .andDo(document.document(
                             requestHeaders(HEADER_ACCESS_TOKEN),
                             pathParameters(
-                                    parameterWithName("commentId").attributes(getTypeFormat(JsonFieldType.NUMBER))
+                                    parameterWithName("commentId").attributes(
+                                                    getTypeFormat(JsonFieldType.NUMBER))
                                             .description("삭제할 댓글 ID")),
                             responseFields(commonResponseFieldsOnly())));