From 009ea2a91672d0755bee1060db0c928eb035437b Mon Sep 17 00:00:00 2001
From: kkw610 <kkw61976@gmail.com>
Date: Sun, 31 May 2026 21:18:01 +0900
Subject: [PATCH] =?UTF-8?q?fix:=20=EC=9D=B5=EB=AA=85=20=EB=B2=88=ED=98=B8?=
 =?UTF-8?q?=20=EA=B2=B0=EC=A0=95=20=EB=B0=A9=EC=8B=9D=20MAX=20=EA=B8=B0?=
 =?UTF-8?q?=EB=B0=98=EC=9C=BC=EB=A1=9C=20=EB=B3=80=EA=B2=BD=20=EB=B0=8F=20?=
 =?UTF-8?q?V5=20=EB=A7=88=EC=9D=B4=EA=B7=B8=EB=A0=88=EC=9D=B4=EC=85=98?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../repository/QuestionAnonymousIdentityRepository.java   | 8 ++++++++
 .../project/domain/question/service/QuestionService.java  | 2 +-
 ..._add_unique_constraint_question_anonymous_identity.sql | 3 +++
 3 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 backend/src/main/resources/db/migration/V5__add_unique_constraint_question_anonymous_identity.sql

diff --git a/backend/src/main/java/com/example/Piroin/project/domain/question/repository/QuestionAnonymousIdentityRepository.java b/backend/src/main/java/com/example/Piroin/project/domain/question/repository/QuestionAnonymousIdentityRepository.java
index cab03c1..53448d9 100644
--- a/backend/src/main/java/com/example/Piroin/project/domain/question/repository/QuestionAnonymousIdentityRepository.java
+++ b/backend/src/main/java/com/example/Piroin/project/domain/question/repository/QuestionAnonymousIdentityRepository.java
@@ -5,6 +5,8 @@
 import com.example.Piroin.project.domain.user.entity.User;
 import com.example.Piroin.project.domain.user.enums.Role;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 import java.util.Optional;
 
@@ -18,4 +20,10 @@ public interface QuestionAnonymousIdentityRepository extends JpaRepository<Quest
     // 용도: 새 익명 번호 발급 시 역할별로 따로 카운트
     // MEMBER → 익명1, 익명2... / ADMIN → 운영진1, 운영진2...
     int countByQuestionAndUser_Role(Question question, Role role);
+
+    @Query("SELECT COALESCE(MAX(a.anonymousNo), 0) FROM QuestionAnonymousIdentity a " + "WHERE a.question = :question AND a.user.role = :role")
+    int findMaxAnonymousNoByQuestionAndRole(
+            @Param("question") Question question,
+            @Param("role") Role role
+    );
 }
\ No newline at end of file
diff --git a/backend/src/main/java/com/example/Piroin/project/domain/question/service/QuestionService.java b/backend/src/main/java/com/example/Piroin/project/domain/question/service/QuestionService.java
index 3291b25..a1aca36 100644
--- a/backend/src/main/java/com/example/Piroin/project/domain/question/service/QuestionService.java
+++ b/backend/src/main/java/com/example/Piroin/project/domain/question/service/QuestionService.java
@@ -196,7 +196,7 @@ private String assignAnonymousIdentity(Question question, User commenter) {
                 .orElseGet(() -> {
                     // 처음 댓글 다는 유저 → 역할별 카운트 기반으로 새 번호 부여
                     int nextNo = anonymousIdentityRepository
-                            .countByQuestionAndUser_Role(question, commenter.getRole()) + 1;
+                            .findMaxAnonymousNoByQuestionAndRole(question, commenter.getRole()) + 1;
 
                     anonymousIdentityRepository.save(QuestionAnonymousIdentity.builder()
                             .question(question)
diff --git a/backend/src/main/resources/db/migration/V5__add_unique_constraint_question_anonymous_identity.sql b/backend/src/main/resources/db/migration/V5__add_unique_constraint_question_anonymous_identity.sql
new file mode 100644
index 0000000..5fbcf3e
--- /dev/null
+++ b/backend/src/main/resources/db/migration/V5__add_unique_constraint_question_anonymous_identity.sql
@@ -0,0 +1,3 @@
+ALTER TABLE question_anonymous_identity
+    ADD CONSTRAINT uq_question_anonymous_identity_question_user
+    UNIQUE (question_id, user_id);
\ No newline at end of file