我正在使用 C# 在 Visual Studio 2010 中编写一个 Web 应用程序。Web 应用程序执行复杂的 SQL Server 2008 语句,如果同时多次调用同一个 .aspx 页面,有时会导致死锁。建议的解决方案是使用 SQL 服务器手段来防止这些死锁,但我的问题是我不太了解它,C# 不是这样,我知道得更好。
所以我想知道,我在 ASP.NET 页面中使用锁(或 C# 中的锁,或名为 mutex 的 Windows)而不是通过 SQL 服务器进行锁定以防止这些死锁有什么缺点?
PS。有问题的 SQL Server 数据库仅供此 Web 应用程序使用。
编辑:以下是执行 SQL 语句的 C# 代码:
int iNumRows = 0;
using (SqlConnection cn = new SqlConnection(strConnection))
{
cn.Open();
using (SqlCommand cmd = new SqlCommand(strSQL, cn))
{
//Use C# lock here
iNumRows = Convert.ToInt32(cmd.ExecuteScalar());
//Release C# lock here
}
}
这是一个 SQL 示例(实际上是由 C# 脚本动态组成的):
SET XACT_ABORT ON;
BEGIN TRANSACTION;
DELETE FROM [dbo].[t_Log_2]
WHERE [idtm]<'2011-03-12 08:41:57';
WITH ctx AS(
SELECT MIN([idtm]) AS mdIn,
MAX([odtm]) AS mdOut
FROM [dbo].[t_Log_2]
WHERE [type] = 0
AND [state] = 0
AND [huid] = N'18ef4d56-6ef3-906a-a711-88d1bd6ab2d4'
AND [odtm] >= '2013-03-11 06:33:32'
AND [idtm] <= '2013-03-11 06:43:12'
)
INSERT INTO [dbo].[t_Log_2]
([oid],[idtm],[odtm],[type],[state],[huid],
[cnm],[cmdl],[batt],[dvtp0],[dvtp1])
SELECT
2,
CASE WHEN mdIn IS NOT NULL
AND mdIn < '2013-03-11 06:33:32'
THEN mdIn
ELSE '2013-03-11 06:33:32'
END,
CASE WHEN mdOut IS NOT NULL
AND mdOut > '2013-03-11 06:43:12'
THEN mdOut
ELSE '2013-03-11 06:43:12'
END,
0,
0,
N'18ef4d56-6ef3-906a-a711-88d1bd6ab2d4',
null,
null,
0,
1,
null
FROM ctx
SELECT ROWCOUNT_BIG()
DELETE FROM [dbo].[t_Log_2]
WHERE [type] = 0
AND [state] = 0
AND [huid] = N'18ef4d56-6ef3-906a-a711-88d1bd6ab2d4'
AND [odtm] >= '2013-03-11 06:33:32'
AND [idtm] <= '2013-03-11 06:43:12'
AND [id] <> SCOPE_IDENTITY()
DELETE FROM [dbo].[t_Log_2]
WHERE [type] = 0
AND [huid] = N'18ef4d56-6ef3-906a-a711-88d1bd6ab2d4'
AND [idtm] >= (SELECT [idtm] FROM [dbo].[t_Log_2]
WHERE [id] = SCOPE_IDENTITY())
AND [odtm] <= (SELECT [odtm] FROM [dbo].[t_Log_2]
WHERE [id] = SCOPE_IDENTITY())
AND [id] <> SCOPE_IDENTITY()
;WITH ctx1 AS(
SELECT [idtm] AS dI
FROM [dbo].[t_Log_2]
WHERE [id] = SCOPE_IDENTITY()
)
UPDATE [dbo].[t_Log_2]
SET [odtm] = ctx1.dI
FROM ctx1
WHERE [id] <> SCOPE_IDENTITY()
AND [type] = 0
AND [huid] = N'18ef4d56-6ef3-906a-a711-88d1bd6ab2d4'
AND [idtm] < ctx1.dI
AND [odtm] > ctx1.dI
;WITH ctx2 AS(
SELECT [odtm] AS dO
FROM [dbo].[t_Log_2]
WHERE [id] = SCOPE_IDENTITY()
)
UPDATE [dbo].[t_Log_2]
SET [idtm] = ctx2.dO
FROM ctx2
WHERE [id] <> SCOPE_IDENTITY()
AND [type] = 0
AND [huid] = N'18ef4d56-6ef3-906a-a711-88d1bd6ab2d4'
AND [idtm] < ctx2.dO
AND [odtm] > ctx2.dO
COMMIT TRANSACTION;
SET XACT_ABORT OFF