fix: N+1 문제 해결

#821
woowacourse-teams · Nov 8, 2023 · 0d180a6 · 0d180a6
1 parent 9998b29
commit 0d180a6
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Showing 7 changed files with 32 additions and 20 deletions.
diff --git a/backend/emm-sale/src/main/java/com/emmsale/member/domain/Member.java b/backend/emm-sale/src/main/java/com/emmsale/member/domain/Member.java
@@ -35,20 +35,23 @@ public class Member extends BaseEntity {
   private String githubUsername;
 
   public Member(final Long id, final Long githubId, final String imageUrl, final String name,
+      final String description,
       final String githubUsername) {
     this.id = id;
     this.githubId = githubId;
     this.imageUrl = imageUrl;
     this.name = name;
-    this.description = DEFAULT_DESCRIPTION;
+    this.description = description;
     this.githubUsername = githubUsername;
   }
 
+  public Member(final Long id, final Long githubId, final String imageUrl, final String name,
+      final String githubUsername) {
+    this(id, githubId, imageUrl, name, DEFAULT_DESCRIPTION, githubUsername);
+  }
+
   public Member(final Long githubId, final String imageUrl, final String githubUsername) {
-    this.githubId = githubId;
-    this.imageUrl = imageUrl;
-    this.description = DEFAULT_DESCRIPTION;
-    this.githubUsername = githubUsername;
+    this(null, githubId, imageUrl, null, DEFAULT_DESCRIPTION, githubUsername);
   }
 
   public void updateName(final String name) {

diff --git a/backend/emm-sale/src/main/java/com/emmsale/message_room/application/RoomQueryService.java b/backend/emm-sale/src/main/java/com/emmsale/message_room/application/RoomQueryService.java
@@ -51,9 +51,6 @@ public List<RoomResponse> findAll(final Member loginMember, final Long memberId)
         .map(messageOverview ->
             RoomResponse.from(
                 messageOverview,
-                memberRepository.findById(messageOverview.getSenderId())
-                    .orElseThrow(() -> new MemberException(NOT_FOUND_MEMBER)),
-                // TODO: 2023/11/05 N+1 문제
                 findInterlocutor(interlocutorIdPerRoomExceptMe.get(messageOverview.getRoomUUID()))
             ))
         .collect(Collectors.toList());

diff --git a/backend/emm-sale/src/main/java/com/emmsale/message_room/application/dto/RoomResponse.java b/backend/emm-sale/src/main/java/com/emmsale/message_room/application/dto/RoomResponse.java
@@ -17,7 +17,6 @@ public class RoomResponse {
 
   public static RoomResponse from(
       final MessageOverview messageOverview,
-      final Member recentMessageSender,
       final Member interlocutor
   ) {
     return new RoomResponse(
@@ -26,7 +25,7 @@ public static RoomResponse from(
         MessageResponse.from(new Message(
             messageOverview.getId(),
             messageOverview.getContent(),
-            recentMessageSender,
+            messageOverview.getSender(),
             messageOverview.getRoomUUID(),
             messageOverview.getCreatedAt()))
     );

diff --git a/...mm-sale/src/main/java/com/emmsale/message_room/infrastructure/persistence/MessageDao.java b/...mm-sale/src/main/java/com/emmsale/message_room/infrastructure/persistence/MessageDao.java
@@ -1,6 +1,7 @@
 package com.emmsale.message_room.infrastructure.persistence;
 
 
+import com.emmsale.member.domain.Member;
 import com.emmsale.message_room.infrastructure.persistence.dto.MessageOverview;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
@@ -14,9 +15,16 @@ public class MessageDao {
 
   private static final RowMapper<MessageOverview> ROW_MAPPER = (rs, rowNum) ->
       new MessageOverview(
-          rs.getLong("id"),
+          rs.getLong("m2.id"),
           rs.getString("content"),
-          rs.getLong("sender_id"),
+          new Member(
+              rs.getLong("sender.id"),
+              rs.getLong("github_id"),
+              rs.getString("image_url"),
+              rs.getString("name"),
+              rs.getString("description"),
+              rs.getString("github_username")
+          ),
           rs.getTimestamp("created_at").toLocalDateTime(),
           rs.getString("room_id")
       );
@@ -27,12 +35,15 @@ public List<MessageOverview> findRecentlyMessages(final Long memberId) {
     StringBuilder sqlBuilder = new StringBuilder();
 
     sqlBuilder
-        .append("SELECT m2.id, m2.content, m2.sender_id, m2.created_at, m2.room_id ")
+        .append("SELECT m2.id, m2.content, m2.sender_id, m2.created_at, m2.room_id, ")
+        .append(
+            "sender.id, sender.github_id, sender.image_url, sender.name, sender.description, sender.github_username ")
         .append("FROM room r ")
         .append("JOIN (SELECT room_id, MAX(created_at) as max_created_at ")
         .append("      FROM message ")
         .append("      GROUP BY room_id) m1 ON r.uuid = m1.room_id ")
         .append("JOIN message m2 ON m1.room_id = m2.room_id AND m1.max_created_at = m2.created_at ")
+        .append("JOIN member sender ON m2.sender_id = sender.id ")
         .append("WHERE r.member_id = ? ")
         .append("AND m2.created_at > r.last_exited_time ")
         .append("ORDER BY m2.created_at DESC");

diff --git a/...rc/main/java/com/emmsale/message_room/infrastructure/persistence/dto/MessageOverview.java b/...rc/main/java/com/emmsale/message_room/infrastructure/persistence/dto/MessageOverview.java
@@ -1,5 +1,6 @@
 package com.emmsale.message_room.infrastructure.persistence.dto;
 
+import com.emmsale.member.domain.Member;
 import java.time.LocalDateTime;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
@@ -10,7 +11,7 @@ public class MessageOverview {
 
   private final Long id;
   private final String content;
-  private final Long senderId;
+  private final Member sender;
   private final LocalDateTime createdAt;
   private final String roomUUID;
 }
diff --git a/...end/emm-sale/src/test/java/com/emmsale/message_room/application/RoomQueryServiceTest.java b/...end/emm-sale/src/test/java/com/emmsale/message_room/application/RoomQueryServiceTest.java
@@ -107,23 +107,23 @@ void test_findAll() throws Exception {
     final MessageOverview messageOverview1 = new MessageOverview(
         resultMessage1.getId(),
         resultMessage1.getContent(),
-        resultMessage1.getSender().getId(),
+        resultMessage1.getSender(),
         resultMessage1.getCreatedAt(),
         resultMessage1.getRoomId()
     );
 
     final MessageOverview messageOverview2 = new MessageOverview(
         resultMessage2.getId(),
         resultMessage2.getContent(),
-        resultMessage2.getSender().getId(),
+        resultMessage2.getSender(),
         resultMessage2.getCreatedAt(),
         resultMessage2.getRoomId()
     );
 
     final List<RoomResponse> expect = List.of(
-        RoomResponse.from(messageOverview1, resultMessage1.getSender(),
+        RoomResponse.from(messageOverview1,
             memberRepository.findById(room1Interlocutor.getId()).get()),
-        RoomResponse.from(messageOverview2, resultMessage2.getSender(),
+        RoomResponse.from(messageOverview2,
             memberRepository.findById(room2Interlocutor.getId()).get())
     );
 

diff --git a/...ale/src/test/java/com/emmsale/message_room/infrastructure/persistence/MessageDaoTest.java b/...ale/src/test/java/com/emmsale/message_room/infrastructure/persistence/MessageDaoTest.java
@@ -109,14 +109,14 @@ void test_findRecentlyMessages() throws Exception {
         new MessageOverview(
             resultMessage1.getId(),
             resultMessage1.getContent(),
-            resultMessage1.getSender().getId(),
+            resultMessage1.getSender(),
             resultMessage1.getCreatedAt(),
             resultMessage1.getRoomId()
         ),
         new MessageOverview(
             resultMessage2.getId(),
             resultMessage2.getContent(),
-            resultMessage2.getSender().getId(),
+            resultMessage2.getSender(),
             resultMessage2.getCreatedAt(),
             resultMessage2.getRoomId()
         )
@@ -128,6 +128,7 @@ void test_findRecentlyMessages() throws Exception {
     //then
     Assertions.assertThat(actual)
         .usingRecursiveComparison()
+        .ignoringFields("sender.createdAt", "sender.updatedAt")
         .isEqualTo(expect);
   }
 }