嵌套條件運算

Question

使用VS 2013（不是C＃6.0還）

我有以下的LINQ其工作原理：

var radData = (from stop in dbContext.stop_details 
       join del in dbContext.stop_event on stop.id equals del.stop_id into Inners 
       from sd in Inners.DefaultIfEmpty() 
       where stop.ship_date == startDate && stop.cust_ref_5_terminalID == "HEND" 
       select new 
       { 
        shipDate = stop.ship_date, 
        custRef = stop.cust_ref_5_terminalID, 
        name = stop.customer.customer_name, 
        ontime = (int?)sd.ontime_performance, 
        OTP = ((int?)sd.ontime_performance) < 1 ? "Ontime" : "Late" 
       }).ToList(); 

但OTP需求價值爲以下取決於ontime_performance：

• 空 - 「打開」
• < 1 「龍泰」
• 1 「晚一天」
• 2 「兩天遲到」
• 「> 2 「的三個或更多日晚」

有沒有辦法窩呢？到目前爲止，我沒有嘗試過任何工作..

謝謝。

Answer 1

你可以連許多?:如下：

var radData = (from stop in dbContext.stop_details 
       join del in dbContext.stop_event on stop.id equals del.stop_id into Inners 
       from sd in Inners.DefaultIfEmpty() 
       where stop.ship_date == startDate && 
        stop.cust_ref_5_terminalID == "HEND" 

       let value = ((int?)sd.ontime_performance) 
       select new 
       { 
        shipDate = stop.ship_date, 
        custRef = stop.cust_ref_5_terminalID, 
        name = stop.customer.customer_name, 
        ontime = (int?)sd.ontime_performance, 
        OTP = value == null ? "Open" : 
         value < 1 ? "On time" : 
         value == 1 ? "One Day Late" : 
         value == 2 ? "Two Days Late" : "Three or more days late" 
       }).ToList(); 

您也可以在現場存儲在一個變量，所以你不需要每次都投它：let value = ((int?)sd.ontime_performance)

BTW - 現場您可以將value < 1更改爲value == 0。與其他條件相一致，不易混淆