diff --git a/src/main/java/com/yxt/yyth/biz/lpkgiftcard/LpkGiftCardMapper.xml b/src/main/java/com/yxt/yyth/biz/lpkgiftcard/LpkGiftCardMapper.xml
index 879483f..68a703e 100644
--- a/src/main/java/com/yxt/yyth/biz/lpkgiftcard/LpkGiftCardMapper.xml
+++ b/src/main/java/com/yxt/yyth/biz/lpkgiftcard/LpkGiftCardMapper.xml
@@ -25,7 +25,9 @@
         </where>
     </select>
     <select id="selctMaxSerNum" resultType="java.lang.String">
-        SELECT MAX(lpk_giftcard.serialNumber) as sNo FROM lpk_giftcard
+        SELECT MAX(serialNumber) as sNo
+        FROM lpk_giftcard
+        WHERE LENGTH(serialNumber) = 8
     </select>