fix: Expo 알림 토큰 추가 -> 업데이트 방식으로 수정

src/main/java/gg/agit/konect/domain/notification/model/NotificationDeviceToken.java

@@ -22,7 +22,7 @@
 @Table(
     name = "notification_device_token",
     uniqueConstraints = {
-        @UniqueConstraint(name = "uq_notification_device_token_token", columnNames = "token")
+        @UniqueConstraint(name = "uq_notification_device_token_user_id", columnNames = "user_id")
     }
 )
 @NoArgsConstructor(access = PROTECTED)
@@ -37,7 +37,7 @@ public class NotificationDeviceToken extends BaseEntity {
     @JoinColumn(name = "user_id", nullable = false)
     private User user;
 
-    @Column(name = "token", length = 255, nullable = false, unique = true)
+    @Column(name = "token", length = 255, nullable = false)
     private String token;
 
     private NotificationDeviceToken(Integer id, User user, String token) {
@@ -50,7 +50,7 @@ public static NotificationDeviceToken of(User user, String token) {
         return new NotificationDeviceToken(null, user, token);
     }
 
-    public void updateUser(User user) {
-        this.user = user;
+    public void updateToken(String token) {
+        this.token = token;
     }
 }

src/main/java/gg/agit/konect/domain/notification/repository/NotificationDeviceTokenRepository.java

@@ -11,7 +11,7 @@
 
 public interface NotificationDeviceTokenRepository extends Repository<NotificationDeviceToken, Integer> {
 
-    Optional<NotificationDeviceToken> findByToken(String token);
+    Optional<NotificationDeviceToken> findByUserId(Integer userId);
 
     @Query("""
         SELECT ndt
@@ -31,13 +31,6 @@ Optional<NotificationDeviceToken> findByUserIdAndToken(
         """)
     List<String> findTokensByUserId(@Param("userId") Integer userId);
 
-    @Query("""
-        SELECT ndt.user.id
-        FROM NotificationDeviceToken ndt
-        WHERE ndt.token = :token
-        """)
-    Optional<Integer> findUserIdByToken(@Param("token") String token);
-
     void save(NotificationDeviceToken notificationDeviceToken);
 
     void delete(NotificationDeviceToken notificationDeviceToken);

src/main/java/gg/agit/konect/domain/notification/service/NotificationService.java

@@ -1,14 +1,12 @@
 package gg.agit.konect.domain.notification.service;
 
-import static gg.agit.konect.global.code.ApiResponseCode.DUPLICATE_NOTIFICATION_TOKEN;
 import static gg.agit.konect.global.code.ApiResponseCode.INVALID_NOTIFICATION_TOKEN;
 
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.regex.Pattern;
 
-import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
@@ -68,32 +66,11 @@ public void registerToken(Integer userId, NotificationTokenRegisterRequest reque
         String token = request.token();
         validateExpoToken(token);
 
-        Integer existingOwnerId = notificationDeviceTokenRepository.findUserIdByToken(token)
-            .orElse(null);
-        if (existingOwnerId != null) {
-            if (!existingOwnerId.equals(userId)) {
-                throw CustomException.of(DUPLICATE_NOTIFICATION_TOKEN);
-            }
-            return;
-        }
-
-        try {
-            notificationDeviceTokenRepository.save(NotificationDeviceToken.of(user, token));
-        } catch (DataIntegrityViolationException e) {
-            Integer ownerId = notificationDeviceTokenRepository.findUserIdByToken(token)
-                .orElse(null);
-            if (ownerId == null) {
-                log.warn(
-                    "Token uniqueness violation without owner: userId={}, token={}",
-                    userId,
-                    token
-                );
-                throw e;
-            }
-            if (!ownerId.equals(userId)) {
-                throw CustomException.of(DUPLICATE_NOTIFICATION_TOKEN);
-            }
-        }
+        notificationDeviceTokenRepository.findByUserId(userId)
+            .ifPresentOrElse(
+                notificationDeviceToken -> notificationDeviceToken.updateToken(token),
+                () -> notificationDeviceTokenRepository.save(NotificationDeviceToken.of(user, token))
+            );
     }
 
     @Transactional

src/main/resources/db/migration/V34__change_notification_device_token_unique_to_user.sql

@@ -0,0 +1,12 @@
+DELETE ndt1
+FROM notification_device_token ndt1
+    INNER JOIN notification_device_token ndt2
+        ON ndt1.user_id = ndt2.user_id
+        AND (
+            ndt1.updated_at < ndt2.updated_at
+            OR (ndt1.updated_at = ndt2.updated_at AND ndt1.id < ndt2.id)
+        );
+
+ALTER TABLE notification_device_token
+    DROP INDEX uq_notification_device_token_token,
+    ADD CONSTRAINT uq_notification_device_token_user_id UNIQUE (user_id);