diff --git a/apps/api/src/services/approval_db.py b/apps/api/src/services/approval_db.py
index 11cec470..0a635006 100644
--- a/apps/api/src/services/approval_db.py
+++ b/apps/api/src/services/approval_db.py
@@ -619,16 +619,26 @@ class ApprovalDBService:
         以 incident_id 查找最新 PENDING approval record 並回填。
         """
         async with get_db_context() as db:
-            values: dict = {"telegram_message_id": telegram_message_id}
+            # 2026-04-10 Claude Sonnet 4.6: 用 raw SQL 避免 SQLAlchemy 推斷 INTEGER
+            # telegram_chat_id 為 BIGINT，ORM update() 會誤用 $N::INTEGER 導致 int32 overflow
+            from sqlalchemy import text as _text
+            params: dict = {
+                "incident_id": incident_id,
+                "telegram_message_id": telegram_message_id,
+                "status": "PENDING",
+            }
+            chat_clause = ""
             if telegram_chat_id is not None:
-                values["telegram_chat_id"] = telegram_chat_id
+                params["telegram_chat_id"] = telegram_chat_id
+                chat_clause = ", telegram_chat_id = CAST(:telegram_chat_id AS BIGINT)"
             await db.execute(
-                update(ApprovalRecord)
-                .where(
-                    ApprovalRecord.incident_id == incident_id,
-                    ApprovalRecord.status == ApprovalStatus.PENDING,
-                )
-                .values(**values)
+                _text(f"""
+                    UPDATE approval_records
+                    SET telegram_message_id = :telegram_message_id{chat_clause}
+                    WHERE incident_id = :incident_id
+                      AND status = :status
+                """),
+                params,
             )
 
     # =========================================================================