diff --git a/app/Service/ShopCarService.php b/app/Service/ShopCarService.php
index 893e826..f761187 100644
--- a/app/Service/ShopCarService.php
+++ b/app/Service/ShopCarService.php
@@ -19,7 +19,7 @@ class ShopCarService implements ShopCarServiceInterface
     {
         //获取ssdb购买记录
         $ssdb = ApplicationContext::getContainer()->get(SSDBTask::class);
-        $record_exists = $ssdb->exec('get',PURCHASE_RECORD. date('Ymd') .'_'.$params['user_id'].'_'.$params['good_id']);
+        $record_exists = $ssdb->exec('get',SsdbKeysPrefix::PURCHASE_RECORD. date('Ymd') .'_'.$params['user_id'].'_'.$params['good_id']);
         if($record_exists)
         {
             $error = [