翻譯SQL語句日期的LINQ到SQL與EF4

Question

使用我有以下SQL命令：

SELECT  CONVERT(varchar, Logged, 103) AS Visited, COUNT(ID) AS Totals 
FROM   tblStats 
GROUP BY CONVERT(varchar, Logged, 103) 
ORDER BY Visited DESC 

我要翻譯成可以與實體框架使用的L2S聲明中，但在使用日期時間類型時，根據我如何嘗試攻擊問題，我得到各種錯誤。

方法：

var results = from s in db.Stats 
     group s by (s.Logged.Date.ToString()) into Grp 
     select new { Day = Grp.Key, Total = Grp.Count() }; 

錯誤：

LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression.

方法：

var results = from s in db.Stats 
       group s by (s.Logged.Date) into Grp 
       select new { Day = Grp.Key, Total = Grp.Count() }; 

錯誤：

The specified type member 'Date' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.

我需要什麼語法才能使查詢工作？

Answer 1

嘗試使用EntityFunctions.TruncateTime方法：

var results = from s in db.Stats 
       group s by EntityFunctions.TruncateTime(s.Logged) into Grp 
       select new { Day = Grp.Key, Total = Grp.Count() }; 

Answer 2

你需要s.Logged.Date的Date部分？

你有沒有嘗試過這樣的：

var results = from s in db.Stats 
       group s by (s.Logged) into Grp 
       select new { Day = Grp.Key, Total = Grp.Count() }; 

我假設Logged是屬性（列在表中）。

編輯：你們是快速的方式。