實體框架與查詢錯誤？

我有一個數組與此數據（ID，Time，和Name）：實體框架與查詢錯誤？

var array = new[] 
{ 
    new { ID = 1, Time = DateTime.ParseExact("12:01", "HH:mm", null), Name = "Peter" }, 
    new { ID = 2, Time = DateTime.ParseExact("12:06", "HH:mm", null), Name = "James" }, 
    new { ID = 3, Time = DateTime.ParseExact("12:03", "HH:mm", null), Name = "Jackie" }, 
    new { ID = 4, Time = DateTime.ParseExact("12:08", "HH:mm", null), Name = "Peter" }, 
    new { ID = 5, Time = DateTime.ParseExact("12:05", "HH:mm", null), Name = "James" }, 
    new { ID = 6, Time = DateTime.ParseExact("12:07", "HH:mm", null), Name = "Peter" }, 
};

在陣列上下面的語句產生正確的結果：

var result = array.OrderBy(x => x.Time).GroupBy(x => x.Name) 
        .SelectMany(x => x).ToArray();

其結果是：

Time: 2013/3/6 12:01:00, Name: Peter 
Time: 2013/3/6 12:07:00, Name: Peter 
Time: 2013/3/6 12:08:00, Name: Peter 
Time: 2013/3/6 12:03:00, Name: Jackie 
Time: 2013/3/6 12:05:00, Name: James 
Time: 2013/3/6 12:06:00, Name: James

但是，當我使用與EF和SQL Server相同的語句時，順序是錯誤的：

Time: 2013/3/6 12:03:00, Name: Jackie 
Time: 2013/3/6 12:06:00, Name: James 
Time: 2013/3/6 12:05:00, Name: James 
Time: 2013/3/6 12:07:00, Name: Peter 
Time: 2013/3/6 12:01:00, Name: Peter 
Time: 2013/3/6 12:08:00, Name: Peter

這裏是SQL EF產生：

SELECT 
[Extent2].[Id] AS [Id], 
[Extent2].[Time] AS [Time], 
[Extent2].[Name] AS [Name] 
FROM (SELECT DISTINCT 
    [Extent1].[Name] AS [Name] 
    FROM [dbo].[testt1] AS [Extent1]) AS [Distinct1] 
INNER JOIN [dbo].[testt1] AS [Extent2] 
ON ([Distinct1].[Name] = [Extent2].[Name]) OR 
    (([Distinct1].[Name] IS NULL) AND ([Extent2].[Name] IS NULL))

沒有order by條款。

我忘了什麼？這是EF的錯誤嗎？
如何從EF中獲取與數組相同的結果？

來源

2013-03-06 Lighter

就不得不說：這是一個非常好問的問題。你有代碼來重現（至少在linq到對象），期望的輸出，實際的輸出，生成的SQL，甚至格式良好。保持！ – Kobi 2013-03-06 07:19:18

就像在SQL：

一組，然後順序：

var result = array.GroupBy(x => x.Name) 
        .Select(x => x.OrderBy(y => y.Time)) 
        .SelectMany(x => x) 
        .ToArray();

但在你的情況我不明白你爲什麼會需要的組都沒有。每次似乎是不同的，所以能產生同樣的結果（至少在你的測試數據），簡單的版本是：

var result = array.OrderBy(x => x.Name) 
        .ThenBy(y => y.Time) 
        .ToArray();

來源

2013-03-06 07:09:19

實體框架與查詢錯誤？

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