如何解决EF5.0下的Find方法生成的SQL语句使用UNION ALL

MyDbContext db = new MyDbContext("test");

#region Find

db.BlogAttachments.Find(1);
/**
*
*
* [Limit1].[C4] AS [C4],
[Limit1].[C5] AS [C5]
FROM ( SELECT TOP (2)
[UnionAll1].[Id] AS [C1],
[UnionAll1].[FileName] AS [C2],
CASE WHEN ([UnionAll1].[C2] = 1) THEN ''0X0X'' ELSE ''0X1X'' END AS [C3],
CASE WHEN ([UnionAll1].[C2] = 1) THEN [UnionAll1].[C1] END AS [C4],
CASE WHEN ([UnionAll1].[C2] = 1) THEN CAST(NULL AS int) ELSE [UnionAll1].[PhotoID] END AS [C5]
FROM (SELECT
[Extent1].[Id] AS [Id],
[Extent1].[FileName] AS [FileName],
CAST(NULL AS int) AS [C1],
[Extent1].[PhotoID] AS [PhotoID],
cast(0 as bit) AS [C2]
FROM [dbo].[PhotoAttachment] AS [Extent1]
UNION ALL
SELECT
[Extent2].[Id] AS [Id],
[Extent2].[FileName] AS [FileName],
[Extent2].[BlogID] AS [BlogID],
CAST(NULL AS int) AS [C1],
cast(1 as bit) AS [C2]
FROM [dbo].[BlogAttachment] AS [Extent2]) AS [UnionAll1]
WHERE [UnionAll1].[Id] = @p0
) AS [Limit1]',N'@p0 int',@p0=1
*
*
* **/

#endregion

#region FirstOrDefault

db.BlogAttachments.SingleOrDefault(n => n.Id == 1);
/**
*
*
* SELECT
[Limit1].[C1] AS [C1],
[Limit1].[Id] AS [Id],
[Limit1].[FileName] AS [FileName],
[Limit1].[BlogID] AS [BlogID]
FROM ( SELECT TOP (1)
[Extent1].[Id] AS [Id],
[Extent1].[FileName] AS [FileName],
[Extent1].[BlogID] AS [BlogID],
'0X0X' AS [C1]
FROM [dbo].[BlogAttachment] AS [Extent1]
WHERE 1 = [Extent1].[Id]
) AS [Limit1]
*
* **/
#endregion