このデータ ( ID
、Time
、およびName
)を含む配列があります。
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" },
};
配列に対する次のステートメントは、正しい結果を生成します。
var result = array.OrderBy(x => x.Time).GroupBy(x => x.Name)
.SelectMany(x => x).ToArray();
結果:
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
しかし、EF と SQL Server で同じステートメントを使用すると、順序が間違っています。
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
EF が生成する SQL は次のとおりです。
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))
order by
条項はありません。
- 私は何を忘れましたか?これはEFのバグですか?
- EF から配列と同じ結果を得るにはどうすればよいですか?