我可以避免Entity框架使用SQL_VARIANT來查詢嗎？

Question

我首先使用實體​​框架6代碼，我有一個簡單的模型：

public class Task
{
    [Key]
    public int aid {get;set;}
    [MaxLength(256)]
    public string Memo {get;set;}
}

我得到一個模型：

int id = 3;
from t in db.Tasks
where t.aid == id
select t;

要么

int id = 3;
db.Tasks.Find(id);

肯定是快但不......

我查看由EF ORM生成的IntelliTrace中的SQL，如下所示：

DECLARE @p__linq__0 AS SQL_VARIANT;
SET @p__linq__0 = 3;

SET STATISTICS TIME ON 
SET STATISTICS IO ON 

SELECT 
    [Limit1].[aid] AS [aid], 
    [Limit1].[Memo] AS [Memo]
    FROM ( SELECT TOP (1) 
        [Extent1].[aid] AS [aid], 
        [Extent1].[Memo] AS [Memo]
        FROM [dbo].[Task] AS [Extent1]
        WHERE [Extent1].[aid] = @p__linq__0
    )  AS [Limit1]

SET STATISTICS TIME OFF
SET STATISTICS IO OFF

我添加SET STATISTICS並在SSMS中測試它。

表'任務'。 掃描計數1 ，...

它使用SQL_VARIANT ！ 執行計划是掃描表而不是集群搜索！

EF為什么這樣做？！ 我可以避免嗎？

（使用SQL Server 2012的LocalDB）

Answer 1

我發現了一個問題！

這是因為我在IntelliTrace中查看sql 。

IntelliTrace將隱藏所有變體並將其顯示為SQL_VARIANT 。

我通過SQL Server Profiler得到了實際的SQL，sql是：

exec sp_executesql N'SELECT 
[Limit1].[aid] AS [aid], 
[Limit1].[Memo] AS [Memo]
FROM ( SELECT TOP (1) 
    [Extent1].[aid] AS [aid], 
    [Extent1].[Memo] AS [Memo]
    FROM [dbo].[Task] AS [Extent1]
    WHERE [Extent1].[aid] = @p__linq__0
)  AS [Limit1]',N'@p__linq__0 int',@p__linq__0=3

使用查找數據是可以的。