fix bugs and improvement

app/models/shift_sale.rb

@@ -28,7 +28,7 @@ class ShiftSale < ApplicationRecord
       #find open shift where is open today and is not closed and login by current cashier
       #DATE(shift_started_at)=? and
       today_date = DateTime.now.strftime("%Y-%m-%d")
-      shift = ShiftSale.where("shift_started_at is not null and shift_closed_at is null and employee_id = #{current_user}").take
+      shift = ShiftSale.where("shift_started_at is not null and shift_closed_at is null and employee_id = ?", current_user).take
       return shift
     #end
   end
@@ -132,7 +132,7 @@ class ShiftSale < ApplicationRecord
       self.commercial_taxes = self.commercial_taxes.to_f - tax.to_f
       self.total_rounding = self.total_rounding - saleobj.rounding_adjustment
       self.total_void = self.total_void + saleobj.grand_total
-      
+
       if saleobj.customer.customer_type == "Dinein"
         self.dining_count = self.dining_count - 1
       else