Generic Database Class Using ADO to Execute Stored Procedures

/***************************************************************
 *  Author:  Amir Samdani
 *
 *  Description: Implementation for the CDatabaseServer class.
 *				 Generaric class To manage database related operations
 * 
 *  Date: 5 July 2000
 *
 *  Module Name:  DatabaseServer.h
 *
 *  Code Updations Come here 
 *
 *     SNO		Who				When           What
 *     ----     -------			-----          -----------
 ****************************************************************/

#include "stdafx.h"
#include "DatabaseServer.h"
#include <stdarg.h>

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CDatabaseServer::CDatabaseServer()
{
	
}

CDatabaseServer::~CDatabaseServer()
{

}

bool CDatabaseServer::getConnectionString(char *szConnectionString)
{
	char szServerName[MAX_COMPUTERNAME_LENGTH + 1];
	DWORD dwSize=sizeof(szServerName) ;
	if(!GetComputerName(szServerName,&dwSize))
		return false ;


	if(!szConnectionString)
		return false ;

	char szUserName[] = "SA";
	char szPassword[] = "";
	char szDatabase[] = "IQRA_DIPLOMA";
	
	sprintf(szConnectionString,"provider=sqloledb;data source=%s;initial catalog=%s;uid=%s;pwd=%s;",szServerName,szDatabase,szUserName,szPassword); 

	return true;
}

VARIANT CDatabaseServer::getExecStoredProcedure(char *szTypes,SAFEARRAY *pSPFields)
{
    _variant_t vtResultRows;
    try
    {
		_CommandPtr   pCmdPtr;
        _RecordsetPtr pRecordset;
        HRESULT hr ; 

		hr = pCmdPtr.CreateInstance(__uuidof(Command));

		char szConnectionString[255];
		getConnectionString(szConnectionString);
		_variant_t vtConnectionString(szConnectionString);
		pCmdPtr->put_ActiveConnection(vtConnectionString);

        pCmdPtr->CommandType = adCmdStoredProc;
		pCmdPtr->CommandText =  szTypes ;
		hr = pCmdPtr->Parameters->Refresh();

	   long lBound,uBound ;
	   HRESULT hresult ;
	   // Getting Safe Array's Lower and Upper Bounds
	   hresult = SafeArrayGetLBound(pSPFields, 1, &lBound);
   	   hresult = SafeArrayGetUBound(pSPFields, 1, &uBound);

	   variant_t vtParamVal;
		_variant_t Index;
		Index.vt = VT_I2;
		Index.iVal = 1 ;
	   for (long iElements=lBound;iElements<=uBound;iElements++)
	   {
			hresult = SafeArrayGetElement(pSPFields, &iElements, &vtParamVal);
			pCmdPtr->GetParameters()->GetItem(Index)->PutValue(vtParamVal) ;
			Index.iVal++ ;
	   }

   		//Execute current Stored Procedure
        _variant_t vEffected ;
		pRecordset = pCmdPtr->Execute(&vEffected,NULL,NULL);
		if (pRecordset->BOF || pRecordset->EndOfFile)
			throw ;
		// Get result set in the form of array
        vtResultRows = pRecordset->GetRows(-1);
        return vtResultRows.Detach() ;
	}
	catch(_com_error &e)
    {
		ATLTRACE((LPCSTR)e.Description());
    }
	vtResultRows.vt = VT_EMPTY ;
    return vtResultRows.Detach();
}

long CDatabaseServer::setExecStoredProcedure(char *szTypes,SAFEARRAY *pSPFields)
{	
    _variant_t vtResultRows;
    try
    {
        _CommandPtr   pCmdPtr;
        _RecordsetPtr pRecordset;
        HRESULT hr ; 

		hr = pCmdPtr.CreateInstance(__uuidof(Command));

		char szConnectionString[255];
		getConnectionString(szConnectionString);
		_variant_t vtConnectionString(szConnectionString);
		pCmdPtr->put_ActiveConnection(vtConnectionString);

        pCmdPtr->CommandType = adCmdStoredProc;
		pCmdPtr->CommandText =  szTypes ;
		hr = pCmdPtr->Parameters->Refresh();

	   long lBound,uBound;
	   HRESULT hresult;
	   // Getting Safe Array's Lower and Upper Bounds
	   hresult = SafeArrayGetLBound(pSPFields, 1, &lBound);
   	   hresult = SafeArrayGetUBound(pSPFields, 1, &uBound);

	   variant_t vtParamVal;
		_variant_t Index;
		Index.vt = VT_I2;
		Index.iVal = 1 ;
	   for (long iElements=lBound;iElements<=uBound;iElements++)
	   {
			hresult = SafeArrayGetElement(pSPFields, &iElements, &vtParamVal);
			pCmdPtr->GetParameters()->GetItem(Index)->PutValue(vtParamVal) ;
			Index.iVal++ ;
	   }

        _variant_t vEffected ;
		pCmdPtr->Execute(&vEffected,NULL,NULL);
		
		// We Are Expecting That Stored Procedures Return ID for Entity to which 
		// NSERT/UPDATE/DELETE  operation is being performed
        return (long)pCmdPtr->Parameters->Item["RETURN_VALUE"]->Value  ;
    }
    catch(_com_error &e)
    {
       ATLTRACE((LPCSTR)e.Description());
    }
    return 0;
}