在存储过程中调用外部的动态连接库(MS SQL Server7.0/2000环境)

CREATE PROCEDURE sp_testdll AS

exec sp_addextendedproc 'SetFileName', 'storeproc.dll'	--声明函数
exec sp_addextendedproc 'addLine', 'storeproc.dll'

declare @szFileName varchar(200)
declare @szText varchar(200)
declare @rt int

Select @szFileName = 'c:/welcome.txt'

EXEC @rt = SetFileName @szFileName	--调用SetFileName函数，参数为--szFileName;
if @rt = 0
begin
select @szText = 'welcome 01'
Exec @rt = addLine @szText					--调用addLine
select @szText = 'welcome 02'
Exec @rt = addLine @szText

end
exec sp_dropextendedproc 'SetFileName'
exec sp_dropextendedproc 'addLine'

dbcc SetFileName(free)
dbcc addLine(free)

#include <windows.h>
#include <srv.h>			//要加入这个.h文件

#define XP_NOERROR      0
#define XP_ERROR        1

#ifndef _DEBUG
#define _DEBUG
#endif

char szFileName[MAX_PATH+1];

void WriteInfo(const char * str);

extern "C" SRVRETCODE WINAPI SetFileName(SRV_PROC* pSrvProc)
{
WriteInfo("SetFileName start");
int paramCount = srv_rpcparams(pSrvProc);
if (paramCount != 1){
WriteInfo("Param Err start");
return XP_ERROR;
}

BYTE		bType;
unsigned long	cbMaxLen;
unsigned long	cbActualLen;
BOOL		fNull;

int ret = srv_paraminfo(pSrvProc, 1, &bType, &cbMaxLen, &cbActualLen,
NULL, &fNull);
if (cbActualLen){
ZeroMemory(szFileName, MAX_PATH+1);
memcpy(szFileName, srv_paramdata(pSrvProc, 1), cbActualLen);
WriteInfo("Set filename ok");
return (XP_NOERROR);
}
else {
WriteInfo("Set filename param failed");
return XP_ERROR;
}
}

extern "C" SRVRETCODE WINAPI addLine(SRV_PROC* pSrvProc)
{
WriteInfo("addline start");
int paramCount = srv_rpcparams(pSrvProc);
if (paramCount != 1){
WriteInfo("addline param err");
return XP_ERROR;
}

BYTE        	bType;
unsigned long	cbMaxLen;
unsigned long	cbActualLen;
BOOL		fNull;
bool		rt = false;

int ret = srv_paraminfo(pSrvProc, 1, &bType, &cbMaxLen, &cbActualLen,
NULL, &fNull);

if (cbActualLen){
int n;
char srt[3] = {0x0d, 0x0a, 0};

char * c = new char[cbActualLen + 3];
if (!c)return XP_ERROR;

ZeroMemory(c, cbActualLen + 3);
memcpy(c, srv_paramdata(pSrvProc, 1), cbActualLen);
memcpy(c+cbActualLen, srt, 3);

HANDLE hf = CreateFile(szFileName, GENERIC_WRITE, FILE_SHARE_WRITE|FILE_SHARE_READ, NULL,
OPEN_ALWAYS, 0, NULL);
if (hf == INVALID_HANDLE_VALUE){
WriteInfo("addline create file err ");
delete []c;
return XP_ERROR;
}

WriteInfo("addline create file ok ");
DWORD dwWt;
n = strlen(c);
SetFilePointer(hf, 0, NULL, FILE_END);
if (WriteFile(hf, c, n, &dwWt, NULL) && dwWt == n)
{
WriteInfo("addline write file ok ");
rt = true;
}
delete []c;
CloseHandle(hf);
}
return rt ? XP_NOERROR:XP_ERROR;
}

inline void WriteInfo(const char * str){
#ifdef _DEBUG
char srt[3] = {0x0d, 0x0a, 0};
HANDLE hf = CreateFile("c://storeproc.log", GENERIC_WRITE, FILE_SHARE_WRITE|FILE_SHARE_READ, NULL,
OPEN_ALWAYS, 0, NULL);
if (hf != INVALID_HANDLE_VALUE){
SetFilePointer(hf, 0, NULL, FILE_END);
DWORD dwWt;
WriteFile(hf, str, strlen(str), &dwWt, NULL);
WriteFile(hf, srt, strlen(srt), &dwWt, NULL);
CloseHandle(hf);
}
else {
MessageBox(NULL, "Write info err", "Message", MB_OK|MB_ICONINFORMATION);
}
#endif
}

BOOL WINAPI DllMain(HINSTANCE hinstDLL,DWORD fdwReason,LPVOID lpReserved)
{
return TRUE;
}