fix(core-attendance): Postgres unnest 파라미터 오류 해결 — 배열+캐스팅 적용

src/main/java/inha/gdgoc/domain/core/attendance/repository/AttendanceRecordRepository.java

@@ -26,11 +26,12 @@ public interface AttendanceRecordRepository extends JpaRepository<AttendanceReco
     /* 배치 업서트(ON CONFLICT) — meeting_id 기준 */
     @Modifying
     @Query(value = """
-                INSERT INTO public.attendance_records (meeting_id, user_id, present, updated_at)
-                SELECT :meetingId, u, :present, NOW()
-                FROM unnest(:userIds) AS u
-                ON CONFLICT (meeting_id, user_id)
-                DO UPDATE SET present = EXCLUDED.present, updated_at = NOW()
+            INSERT INTO public.attendance_records (meeting_id, user_id, present, updated_at)
+            SELECT :meetingId, uid, :present, NOW()
+            FROM unnest(CAST(:userIds AS bigint[])) AS uid
+            ON CONFLICT (meeting_id, user_id)
+            DO UPDATE SET present = EXCLUDED.present, updated_at = NOW()
             """, nativeQuery = true)
-    int upsertBatchByMeetingId(@Param("meetingId") Long meetingId, @Param("userIds") List<Long> userIds, @Param("present") boolean present);
+    int upsertBatchByMeetingId(@Param("meetingId") Long meetingId, @Param("userIds") Long[] userIds,  // 👈 배열
+                               @Param("present") boolean present);
 }

src/main/java/inha/gdgoc/domain/core/attendance/service/CoreAttendanceService.java

@@ -114,7 +114,10 @@ public long setAttendance(String date, List<Long> userIds, boolean present) {
 
         LocalDate d = LocalDate.parse(date);
         Long meetingId = ensureMeetingAndGetId(d);
-        int affected = attendanceRecordRepository.upsertBatchByMeetingId(meetingId, userIds, present);
+
+        Long[] arr = userIds.toArray(Long[]::new); // ✅ List -> Array
+        int affected = attendanceRecordRepository
+                .upsertBatchByMeetingId(meetingId, arr, present);
         return Math.max(affected, 0);
     }