diff --git a/backend/src/main/java/com/zioinfo/mes/common/GlobalExceptionHandler.java b/backend/src/main/java/com/zioinfo/mes/common/GlobalExceptionHandler.java
index 1586a58..8aabecb 100644
--- a/backend/src/main/java/com/zioinfo/mes/common/GlobalExceptionHandler.java
+++ b/backend/src/main/java/com/zioinfo/mes/common/GlobalExceptionHandler.java
@@ -1,6 +1,7 @@
 package com.zioinfo.mes.common;
 
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.dao.DataAccessException;
 import org.springframework.http.HttpStatus;
 import org.springframework.security.access.AccessDeniedException;
 import org.springframework.web.bind.annotation.ExceptionHandler;
@@ -39,6 +40,14 @@ public class GlobalExceptionHandler {
         return ApiResponse.fail(e.getMessage());
     }
 
+    @ExceptionHandler(DataAccessException.class)
+    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
+    public ApiResponse<Void> handleDataAccess(DataAccessException e) {
+        // 보안 불변 규칙: SQL/테이블/쿼리/스택 상세 절대 미노출 — 내부 로그만 남기고 일반 메시지 반환
+        log.error("DB 오류", e);
+        return ApiResponse.fail("ERR-MES-DB: 데이터 처리 중 오류가 발생했습니다");
+    }
+
     @ExceptionHandler(RuntimeException.class)
     @ResponseStatus(HttpStatus.BAD_REQUEST)
     public ApiResponse<Void> handleRuntime(RuntimeException e) {
diff --git a/backend/src/main/resources/mapper/AnalyticsMapper.xml b/backend/src/main/resources/mapper/AnalyticsMapper.xml
index a244b25..af79ba9 100644
--- a/backend/src/main/resources/mapper/AnalyticsMapper.xml
+++ b/backend/src/main/resources/mapper/AnalyticsMapper.xml
@@ -8,7 +8,7 @@
       COALESCE(SUM(good_qty),0) AS total_good,
       COALESCE(SUM(defect_qty),0) AS total_defect,
       ROUND( (COALESCE(SUM(defect_qty),0)::numeric
-              / NULLIF(SUM(good_qty)+SUM(defect_qty),0) * 100), 2) AS defect_rate,
+              / NULLIF(SUM(good_qty)+SUM(defect_qty),0) * 100)::numeric, 2) AS defect_rate,
       (SELECT COUNT(*) FROM mes_workorder
         WHERE status IN ('DONE','CLOSED')
           AND updated_at &gt;= CURRENT_DATE - (#{days} || ' days')::interval) AS completed_workorders