從 CLR UDF 存取機器碼
這個範例會示範如何從資料庫內組件中的使用者定義函數來叫用原生 (Unmanaged) C++ 程式碼的函數。
在這個範例中,工作目錄應該是 c:\test。
請先編譯 C++ 程式碼:
// Win32Sleep.cpp
// compile with: /LD /link /noentry kernel32.lib
#include <windows.h>
extern "C"
__declspec( dllexport ) void _cdecl SleepyLoop(DWORD sleep_interval) {
Sleep(sleep_interval);
}
接下來,將 C# 程式碼編譯為組件:
// proc.cs
// compile with: /target:library
using System;
using System.Threading;
using System.Data.Sql;
using System.Runtime.InteropServices;
public class StoreProcedures {
public static readonly uint SLEEP_LOOP_TIMES = 10;
public static readonly uint SLEEP_DURATION = 1000;
[DllImport(@"c:\test\Win32Sleep.dll")]
internal static extern void SleepyLoop(uint sleepInterval);
public static void SleepInProcedure(int loopTimes) {
for ( int i = 0 ; i < loopTimes ; i++ ) {
// invoke the unmanaged routine
SleepyLoop(SLEEP_DURATION);
}
}
}
最後,執行下列 Transact-SQL:
USE MASTER
GO
IF DB_ID('testdb') IS NOT NULL
DROP DATABASE testdb
GO
CREATE DATABASE testdb
GO
USE testdb
GO
ALTER DATABASE testdb SET TRUSTWORTHY ON
GO
sp_configure 'show advanced options', 1
GO
RECONFIGURE
GO
sp_configure 'clr enabled', 1
GO
RECONFIGURE
GO
CREATE ASSEMBLY myasm FROM 'c:\test\proc.dll' WITH PERMISSION_SET=UNSAFE
go
CREATE PROCEDURE SleepProc(@loopTimes INT)
AS EXTERNAL NAME myasm.[StoreProcedures].[SleepInProcedure]
go
-- sleep 5 seconds
EXEC SleepProc 5
GO