Linq to Sql Sum 没有记录 [英] Linq to Sql Sum with no records

问题描述

我正在创建一个收集整个月累计总数的方法.问题是在给定月份中某些项目可能不收费，因此不会返回任何行.

I am creating a method that collects accumulated totals throughout the month. The problem is that there may not be charges for some of the items in a given month so no rows would be returned.

我可以看到如果没有数据会出错:

I can see how this would error with no data:

double fuelCost = (double)(from a in db.EquipmentFuelLogs
                           where a.wdEquipmentMainGeneralOID == vehicleKey &&    
                                (monthBeginDate < a.Date1 && a.Date1 < monthEndDate)
                           select a.TotalCost).Sum();

检测当月没有燃料交易并将燃料成本设置为 0 的最佳方法是什么?只是尝试捕捉?这篇文章谈到了这个问题，但是没有办法.

What is the best approach to detect no fuel transactions for that month and set the fuel cost to 0? Just do a try catch? This article spoke of the problem but no solution.

推荐答案

我添加了一个 catch 来捕获错误.我从来没有找到不同的解决方案.

I added a catch to catch the error. I never found a different solution.

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