獲取entityframework中每個組的最後記錄？

Question

我想檢索實體框架中每個MobileNo的最後插入記錄。

這是我的表格數據。

ID  RegNo  MobileNo CreatedDate 
26727 190077348 9696562673 13-02-2017 06:31 
26729 123782783 9696562673 13-02-2017 06:35 
45779 530087328 5878525875 07-02-2017 07:23 
99902 120058572 7379130560 08-02-2017 12:39 
64477 180073650 7417516480 10-02-2017 13:47 
81839 240087264 7754990580 11-02-2017 10:47 

，並希望輸出如下

ID  RegNo  MobileNo CreatedDate 
26729 123782783 9696562673 13-02-2017 06:35 
45779 530087328 5878525875 07-02-2017 07:23 
99902 120058572 7379130560 08-02-2017 12:39 
64477 180073650 7417516480 10-02-2017 13:47 
81839 240087264 7754990580 11-02-2017 10:47 

Answer 1

假設你的表的名稱是Items：

var result = dbContext.Items.GroupBy(x => x.MobileNo) 
         .Select(x => x.OrderByDescending(y => y.CreatedDate).First()); 

運行示例：https://dotnetfiddle.net/3ud2pB

Answer 2

嘗試。

;WITH cte AS 
(
    SELECT *, 
     ROW_NUMBER() OVER (PARTITION BY MobileNo ORDER BY CreatedDate DESC) AS rn 
    FROM yourtablename 
) 
SELECT * 
FROM cte 
WHERE rn = 1