C / C++ / MFC

m_pConnection = NULL;
m_strConnection = _T("");
m_pConnection.CreateInstance(__uuidof(Connection));

try
{
    hr = m_pConnection->Open(L"Driver={SQL Server};Server=Server_Name;Database=Database_Name;", L"UID=UserName;", L"PWD=Password;", adOpenUnspecified);
    return hr == S_OK;
}
catch(_com_error &e)
{
    dump_com_error(e);
    return FALSE;
}

PankajB wrote:

catch(_com_error &e)
{
dump_com_error(e);
return FALSE;
}

e.Description()

PankajB wrote:

I am able to test the connection using Visual Studio's Server Explorer option.

PankajB wrote:

m_pConnection is of _ConnectionPtr type

PankajB wrote:

I am getting an error "Invalid Connection"

_ConnectionPtr m_pConn;
m_pConn.CreateInstance (__uuidof(Connection));

#if !defined(AFX_ADO2_H_INCLUDED_)
#define AFX_ADO2_H_INCLUDED_

#if _MSC_VER >= 1000
#pragma once
#endif // _MSC_VER >= 1000
#include <afx.h>
#include <afxdisp.h>
#include <math.h>

#import "C:\Program Files\Common Files\System\ADO\msado15.dll" \
no_namespace rename("EOF", "EndOfFile")

CString IntToStr(int nVal);
CString LongToStr(long lVal);
CString ULongToStr(unsigned long ulVal);
CString DblToStr(double dblVal, int ndigits = 20);
CString DblToStr(float fltVal);

class CDataAccessManager
{
public:
	CDataAccessManager()
	{
		::CoInitialize(NULL);
			
		m_pConnection = NULL;
		m_strConnection = _T("");
		m_pConnection.CreateInstance(__uuidof(Connection));
	}
	
	virtual ~CDataAccessManager()
	{
		CloseDB();
		m_pConnection.Release();
		m_pConnection = NULL;
		m_strConnection = _T("");
		::CoUninitialize();
	}
	
	BOOL OpenDB(LPCTSTR lpstrConnection = _T(""), LPCTSTR lpstrUserID = _T(""), LPCTSTR lpstrPassword = _T(""));
	_ConnectionPtr GetActiveConnection() 
		{return m_pConnection;};
	BOOL Execute(LPCTSTR lpstrExec);
	BOOL IsOpenDB();
	void CloseDB();
	void SetConnectionString(LPCTSTR lpstrConnection)
		{m_strConnection = lpstrConnection;};
	CString GetConnectionString()
		{return m_strConnection;};

protected:
	void dump_com_error(_com_error &e);

public:
	_ConnectionPtr m_pConnection;
	
protected:
	CString m_strConnection;
};

#endif //AFX_ADO2_H_INCLUDED_

#include "ado2.h"

CString IntToStr(int nVal)
{
	CString strRet;
	char buff[10];
	
	itoa(nVal, buff, 10);
	strRet = buff;
	return strRet;
}

CString LongToStr(long lVal)
{
	CString strRet;
	char buff[20];
	
	ltoa(lVal, buff, 10);
	strRet = buff;
	return strRet;
}

CString ULongToStr(unsigned long ulVal)
{
	CString strRet;
	char buff[20];
	
	ultoa(ulVal, buff, 10);
	strRet = buff;
	return strRet;

}

CString DblToStr(double dblVal, int ndigits)
{
	CString strRet;
	char buff[50];

   _gcvt(dblVal, ndigits, buff);
	strRet = buff;
	return strRet;
}

CString DblToStr(float fltVal)
{
	CString strRet;
	char buff[50];
	
   _gcvt(fltVal, 10, buff);
	strRet = buff;
	return strRet;
}

BOOL CDataAccessManager::OpenDB(LPCTSTR lpstrConnection, LPCTSTR lpstrUserID, LPCTSTR lpstrPassword)
{
	HRESULT hr = S_OK;

	if(IsOpenDB())
		CloseDB();

	if(lstrcmp(lpstrConnection, _T("")) != 0)
		m_strConnection = lpstrConnection;

	ASSERT(!m_strConnection.IsEmpty());

	try
	{
		//hr = m_pConnection->Open(_bstr_t(m_strConnection), _bstr_t(lpstrUserID), _bstr_t(lpstrPassword), NULL);
		//hr = m_pConnection->Open(L"Driver={SQL Server};Server=ASHISH-DB\ULXDBSERVER;Database=eDiscoveryDEV;", L"UID=edm;", L"PWD=Password;", adOpenUnspecified);
		hr = m_pConnection->Open(L"DRIVER={sql server};SERVER=ASHISH-DB\ULXDBSERVER;Database=eDiscoveryDEV;" L"UID=edm; PWD=Password;", L"", L"", adOpenUnspecified); 
		return hr == S_OK;
	}
	catch(_com_error &e)
	{
		dump_com_error(e);
		return FALSE;
	}
}

BOOL CDataAccessManager::Execute(LPCTSTR lpstrExec)
{
	ASSERT(m_pConnection != NULL);
	ASSERT(lstrcmp(lpstrExec, _T("")) != 0);
	_variant_t vRecords;
	
	try
	{
		m_pConnection->CursorLocation = adUseClient;
		m_pConnection->Execute(_bstr_t(lpstrExec), &vRecords, adExecuteNoRecords);

		return TRUE;
	}
	catch(_com_error &e)
	{
		dump_com_error(e);
		return FALSE;	
	}
}

BOOL CDataAccessManager::IsOpenDB()
{
	if(m_pConnection )
		return m_pConnection->GetState() != adStateClosed;
	return FALSE;
}

void CDataAccessManager::CloseDB()
{
	if(IsOpenDB())
		m_pConnection->Close();
}

void CDataAccessManager::dump_com_error(_com_error &e)
{
}

// CDataAccessManager.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "ado2.h"

int _tmain(int argc, _TCHAR* argv[])
{
	CDataAccessManager objDAL;
	
	bool bSuccess = objDAL.OpenDB(_T("DRIVER={sql server};SERVER=ASHISH-DB\ULXDBSERVER;Database=LexCoreDB"), _T("edm"), _T("Password"));

	return 0;
}

UINT beginTicks,testData=0,MsTimePerLoop;
while(1)
{        
    beginTicks=GetTickCount();
    
    // do something
    for(int i=0;i<10000;i++) 
        testData= (testData+100)*20-300*20+20;    

    MsTimePerLoop=GetTickCount()-beginTicks;
    
    if(MsTimePerLoop>=5)
    {
        // Context-switch occurs, spend 15 MS
        printf("MsTimePerLoop=%d\n",MsTimePerLoop);
        Sleep(1000);
    }
    else
        // Normal, 0 MS
        printf("MsTimePerLoop=%d\r\n",MsTimePerLoop);
}

yctsai wrote:

The context switch doesn't spend 15 MS (too long).

1. What values have you assigned the members of the COMMTIMEOUTS struct when calling ::SetCommTimeouts()?
   This is essential since your call may block until it receives something on the port.
2. Are you using overlapped I/O?