diff --git a/app/store/service/staff/Config.php b/app/store/service/staff/Config.php
--- a/app/store/service/staff/Config.php
+++ b/app/store/service/staff/Config.php
@@ -11,3 +11,4 @@ use app\store\model\staff\Sport;
 use app\store\model\staff\Staff as StaffModel;
 use app\common\service\BaseService;
+use app\common\service\FixedScaleDecimalResponse;
 use app\store\service\store\User as StoreUserService;
@@ -106,6 +107,7 @@ class Config extends BaseService
         foreach ($pla_data as $v){
-            $pal[] = [
+            // Response only: persisted DECIMAL(5,2) matches MySQL's string contract.
+            $pal[] = FixedScaleDecimalResponse::fields([
                 'strength'=>$v['strength'],
                 'pal'=>$v['pal']
-            ];
+            ], ['pal']);
         }