Question

使用VS 2013（尚未推出C＃6.0）

我有以下可用的LINQ：

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的值必须如下，具体取决于ontime_performance：

Null - ＆＃34; open＆＃34;
＆lt; 1＆＃34; Ontime＆＃34;
1＆＃34;延迟一天＆＃34;
2＆＃34;延迟两天＆＃34;
＆＃39;＆gt; 2＆＃34;迟到三天或更多天＆＃34;

有没有办法筑巢呢？到目前为止我没有尝试过任何工作..

谢谢。

Answer 1

您可以按如下方式链接多个?:：

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();

此外，您可以将字段存储在变量中，因此您不需要每次都将其强制转换：let value = ((int?)sd.ontime_performance)

BTW - 字段为int?您可以将value < 1更改为value == 0。

与其他条件一致，不那么令人困惑

LINQ查询中的嵌套条件运算符

1 个答案: