add balance promotion shop promotion

app/models/balance_promotion.rb

@@ -58,7 +58,7 @@ class BalancePromotion < ActiveRecord::Base
         return "--"
       end
     end
-
+    DEPART_ENUM =  []
     def get_depart_enum
       DEPART_ENUM.clear
       if DEPART_ENUM.length ==0