feat(backend): #359 1단계 — google_place_id 중복 조회 API

- GET /api/admin/restaurants/duplicates/place-id (어드민 전용)
- 그룹별 식당 목록 + video/review/memo 카운트 동봉
- Mapper: findDuplicatePlaceIdRows + Service 그룹핑
- 정리/병합 + UNIQUE 제약은 데이터 위험 분리 위해 후속 PR로

Refs: #359 (조회 단계 완료)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,13 @@
 
 ## 2026-06-15
 
+### 🔍 #359 1단계 — google_place_id 중복 조회 API (v0.1.46)
+- GET /api/admin/restaurants/duplicates/place-id (어드민 전용)
+- 응답: 그룹별 식당 + video/review/memo 카운트 (병합 의사결정 자료)
+- 정리/병합 + UNIQUE 제약은 별도 PR (데이터 위험 분리)
+- 설계서: docs/design/359a-duplicate-place-id-view/README.md
+- Refs: #359 (조회 단계 완료, 후속 분리 유지)
+
 ### 📋 #358 RestaurantUpdateDTO + @Valid 표준화 (v0.1.45)
 - dto/RestaurantUpdateDTO record 신규 (15 필드, 모두 nullable)
 - Bean Validation: @Size/@Pattern(URL or NONE)/@DecimalMin·Max/@Min·Max

backend-java/src/main/java/com/tasteby/controller/AdminRestaurantController.java

@@ -62,6 +62,15 @@ public class AdminRestaurantController {
         return Map.of("success", true, "id", id);
     }
 
+    // #359 1단계 — google_place_id 중복 조회 (정리/UNIQUE는 후속).
+    @GetMapping("/duplicates/place-id")
+    public Map<String, Object> duplicatePlaceIds() {
+        var admin = AuthUtil.requireAdmin();
+        var groups = restaurantService.findDuplicatePlaceIdGroups();
+        log.info("[ADMIN] {} duplicate place_id groups: {}", admin.getSubject(), groups.size());
+        return Map.of("groups", groups, "group_count", groups.size());
+    }
+
     /**
      * 어드민용 hidden 토글.
      */

backend-java/src/main/java/com/tasteby/mapper/RestaurantMapper.java

@@ -39,6 +39,9 @@ public interface RestaurantMapper {
 
     int countUnevaluatedLinks();
 
+    // #359 1단계 — google_place_id 중복 조회
+    List<Map<String, Object>> findDuplicatePlaceIdRows();
+
     Restaurant findById(@Param("id") String id);
 
     List<Map<String, Object>> findVideoLinks(@Param("restaurantId") String restaurantId,

backend-java/src/main/java/com/tasteby/service/RestaurantService.java

@@ -111,6 +111,23 @@ public class RestaurantService {
         return mapper.countUnevaluatedLinks();
     }
 
+    // #359 1단계 — google_place_id 중복 그룹 (참조 카운트 동봉)
+    public List<Map<String, Object>> findDuplicatePlaceIdGroups() {
+        var rows = mapper.findDuplicatePlaceIdRows().stream()
+                .map(JsonUtil::lowerKeys)
+                .toList();
+        Map<String, List<Map<String, Object>>> grouped = new LinkedHashMap<>();
+        for (var r : rows) {
+            String key = (String) r.get("google_place_id");
+            grouped.computeIfAbsent(key, k -> new ArrayList<>()).add(r);
+        }
+        List<Map<String, Object>> out = new ArrayList<>(grouped.size());
+        for (var e : grouped.entrySet()) {
+            out.add(Map.of("google_place_id", e.getKey(), "items", e.getValue()));
+        }
+        return out;
+    }
+
     public void update(String id, Map<String, Object> fields) {
         mapper.updateFields(id, fields);
     }

backend-java/src/main/resources/mybatis/mapper/RestaurantMapper.xml

@@ -353,4 +353,21 @@
         SELECT COUNT(*) FROM video_restaurants WHERE relevance_evaluated_at IS NULL
     </select>
 
+    <!-- #359 1단계 — google_place_id 중복 조회 (그룹 식당 + 참조 카운트) -->
+    <select id="findDuplicatePlaceIdRows" resultType="map">
+        SELECT r.id, r.google_place_id, r.name, r.address,
+               TO_CHAR(r.created_at, 'YYYY-MM-DD"T"HH24:MI:SS') AS created_at,
+               r.hidden,
+               (SELECT COUNT(*) FROM video_restaurants vr WHERE vr.restaurant_id = r.id) AS video_count,
+               (SELECT COUNT(*) FROM user_reviews rv WHERE rv.restaurant_id = r.id) AS review_count,
+               (SELECT COUNT(*) FROM user_memos mm WHERE mm.restaurant_id = r.id) AS memo_count
+        FROM restaurants r
+        WHERE r.google_place_id IN (
+            SELECT google_place_id FROM restaurants
+            WHERE google_place_id IS NOT NULL
+            GROUP BY google_place_id HAVING COUNT(*) > 1
+        )
+        ORDER BY r.google_place_id, r.created_at
+    </select>
+
 </mapper>

docs/design/359a-duplicate-place-id-view/README.md

@@ -0,0 +1,47 @@
+# 설계서: google_place_id 중복 조회 API (#359 1단계)
+
+> **상태**: Approved
+> **작성**: [AI] Architect · **최종수정**: 2026-06-15
+> **추적성** — Redmine: #359 · 1단계(조회 전용, 위험 0). 2단계(자동 병합) / 3단계(UNIQUE)는 별도 PR.
+> · 구현 파일: `backend-java/src/main/resources/mybatis/mapper/RestaurantMapper.xml`, `backend-java/src/main/java/com/tasteby/mapper/RestaurantMapper.java`, `backend-java/src/main/java/com/tasteby/service/RestaurantService.java`, `backend-java/src/main/java/com/tasteby/controller/AdminRestaurantController.java`
+> · 테스트: 본 범위 밖 (수동 — admin token으로 호출).
+
+## 1. 목적 (Why)
+
+같은 `google_place_id`에 다중 식당이 매핑된 경우 운영자가 어떤 것을 유지/병합할지 결정 필요. 본 단계는 **조회만** — 그룹과 후보 식당을 메타데이터(연결된 영상/리뷰/메모 수)와 함께 보여줘 의사결정 자료 제공.
+
+## 2. 범위
+
+- 포함: `GET /api/admin/restaurants/duplicates/place-id` — 운영자만, 그룹별 식당 + 카운트 동봉.
+- 제외 (별도 PR): 병합/삭제, UNIQUE constraint.
+
+## 3. 인수조건
+
+- [ ] requireAdmin 보호.
+- [ ] 응답 구조: `[{ google_place_id, items: [{ id, name, address, created_at, video_count, review_count, memo_count, hidden }] }]`.
+- [ ] 그룹은 `COUNT(*) > 1` 만 반환.
+
+## 4. SQL
+
+```sql
+SELECT r.id, r.google_place_id, r.name, r.address,
+       TO_CHAR(r.created_at, 'YYYY-MM-DD"T"HH24:MI:SS') AS created_at,
+       r.hidden,
+       (SELECT COUNT(*) FROM video_restaurants vr WHERE vr.restaurant_id = r.id) AS video_count,
+       (SELECT COUNT(*) FROM reviews rv WHERE rv.restaurant_id = r.id) AS review_count,
+       (SELECT COUNT(*) FROM memos mm WHERE mm.restaurant_id = r.id) AS memo_count
+FROM restaurants r
+WHERE r.google_place_id IN (
+    SELECT google_place_id FROM restaurants
+    WHERE google_place_id IS NOT NULL
+    GROUP BY google_place_id HAVING COUNT(*) > 1
+)
+ORDER BY r.google_place_id, r.created_at
+```
+
+Service 계층에서 google_place_id로 그룹핑하여 응답 구조 변환.
+
+## 5. 엣지케이스
+
+- 중복 0건 → 빈 배열.
+- 누군가가 google_place_id를 동시에 변경 중 → 다음 호출에서 반영 (캐시 X).