easyUI MVC3一些注意的东东(3)

统计合计是有null值的处理

例子：

   decimal ? allIn = (from b in db.ST_BillInDetail
                             join sb in db.ST_Bill on b.billId equals sb.id
                             where (sb.billDate >= startDate && sb.billDate <= endDate && sb.depotId == depotID && sb.billType == (int)ST_BillType.IN )
                             select (decimal?)b.GoodPrice * b.goodCount).Sum();