Question

任何人都知道为什么EF6会不必要地将Int16重新投射到smallint？使用日志记录功能，我看到它执行了以下查询：

SELECT 
    [Project1].[LabelName] AS [LabelName], Project1.Usage, Project1.FacilityID
    FROM ( SELECT 
        [Extent1].[LabelName] AS [LabelName], 
        [Extent1].[Usage] AS [Usage],
        extent1.facilityid
        FROM [dbo].[Label] AS [Extent1]
        WHERE (0 = [Extent1].[DeleteInd]) 
        AND ([Extent1].[FacilityID] IN (cast(1 as smallint), cast(5 as smallint))) 
        AND (([Extent1].[LabelName] LIKE @p__linq__0 ESCAPE '~') OR ([Extent1].[LabelName] LIKE @p__linq__1 ESCAPE '~'))
    )  AS [Project1]
    ORDER BY [Project1].[Usage] DESC
-- p__linq__0: '%test%' (Type = AnsiString, Size = 8000)
-- p__linq__1: 'test%' (Type = AnsiString, Size = 8000)
-- Executing at 12/6/2013 4:08:49 PM -08:00
-- Completed in 16 ms with result: SqlDataReader

这是Linq查询：

Context.Database.Log = Console.Write;
var labels = (from label in Context.Labels
                where label.DeleteInd == false &&
                Settings.FacilitySearch.Contains(label.Facility.FacilityID)  &&
                (label.LabelName.Contains(searchText) || label.LabelName.StartsWith(searchText))
                orderby label.Usage descending
                select label.LabelName);

return labels.ToList();

EF知道FacilityId是smallint＆lt; - ＆gt; Int16（会显示图片，但信誉点不够： - /）

项目： C＃WinForms .NET 4.0 Windows 7 SP1 Visual Studio 2010

Answer 1

我猜测在这种特殊情况下不需要这种转换，但是编写始终执行强制转换的代码更简单，并且假设SQL Server可能无论如何都会优化它。开发人员可能认为生成不必要的复杂SQL比维护不必要的复杂代码更好。

实体框架6.0.1不必要地施放smallint

1 个答案: