ado.cpp

本动态库主要为了根据对数据源操作使用SQL语句了直接嵌入VC过程来实现,可以用在很多数据库种类的基本操作,实现了简单的SQL在外部调用动态库尔嵌入.数据库框架的设计不会影像本动态库的使用.

//
//  MODULE: Ado.cpp
//
//	AUTHOR: Carlos Antollini 
//
//  mailto: [e-mail]
//
//	Date: 03/21/2002
//
//	Version 2.01
// 
#include "ado.h"

#define ChunkSize 100
///////////////////////////////////////////////////////
//
// CADODatabase Class
//

DWORD CADODatabase::GetRecordCount(_RecordsetPtr m_pRs)
{
	DWORD numRows = 0;
	
	numRows = m_pRs->GetRecordCount();

	if(numRows == -1)
	{
		if(m_pRs->EndOfFile != VARIANT_TRUE)
			m_pRs->MoveFirst();

		while(m_pRs->EndOfFile != VARIANT_TRUE)
		{
			numRows++;
			m_pRs->MoveNext();
		}
		if(numRows > 0)
			m_pRs->MoveFirst();
	}
	return numRows;
}

BOOL CADODatabase::Open(LPCTSTR lpstrConnection, LPCTSTR lpstrUserID, LPCTSTR lpstrPassword)
{
	HRESULT hr = S_OK;

	if(IsOpen())
		Close();

	if(strcmp(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);
		return hr == S_OK;
	}
	catch(_com_error &e)
	{
		dump_com_error(e);
		return FALSE;
	}
	
}

void CADODatabase::dump_com_error(_com_error &e)
{
	CString ErrorStr;
	
	
	_bstr_t bstrSource(e.Source());
	_bstr_t bstrDescription(e.Description());
	ErrorStr.Format( "CADODataBase Error\n\tCode = %08lx\n\tCode meaning = %s\n\tSource = %s\n\tDescription = %s\n",
		e.Error(), e.ErrorMessage(), (LPCSTR)bstrSource, (LPCSTR)bstrDescription );
	m_strLastError = _T("Connection String = " + GetConnectionString() + '\n' + ErrorStr);
	m_dwLastError = e.Error(); 
	#ifdef _DEBUG
		AfxMessageBox( ErrorStr, MB_OK | MB_ICONERROR );
	#endif	
}

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

void CADODatabase::Close()
{
	if(IsOpen())
		m_pConnection->Close();
}


///////////////////////////////////////////////////////
//
// CADORecordset Class
//

CADORecordset::CADORecordset(CADODatabase* pAdoDatabase)
{
	m_pRecordset = NULL;
	m_pCmd = NULL;
	m_strQuery = _T("");
	m_pRecordset.CreateInstance(__uuidof(Recordset));
	m_pCmd.CreateInstance(__uuidof(Command));
	m_nEditStatus = CADORecordset::dbEditNone;
	m_nSearchDirection = CADORecordset::searchForward;

	m_pConnection = pAdoDatabase->GetActiveConnection();
}

BOOL CADORecordset::Open(_ConnectionPtr mpdb, LPCTSTR lpstrExec, int nOption)
{	
	Close();
	
	if(strcmp(lpstrExec, _T("")) != 0)
		m_strQuery = lpstrExec;

	ASSERT(!m_strQuery.IsEmpty());
	
	m_strQuery.TrimLeft();
	BOOL bIsSelect = m_strQuery.Mid(0, strlen("Select ")).CompareNoCase("select ") == 0 && nOption == openUnknown;

	try
	{
		m_pRecordset->CursorType = adOpenStatic;
		m_pRecordset->CursorLocation = adUseClient;
		if(bIsSelect || nOption == openQuery || nOption == openUnknown)
			m_pRecordset->Open((LPCSTR)m_strQuery, _variant_t((IDispatch*)mpdb, TRUE), 
							adOpenStatic, adLockOptimistic, adCmdUnknown);
		else if(nOption == openTable)
			m_pRecordset->Open((LPCSTR)m_strQuery, _variant_t((IDispatch*)mpdb, TRUE), 
							adOpenKeyset, adLockOptimistic, adCmdTable);
		else if(nOption == openStoredProc)
		{
			m_pCmd->ActiveConnection = mpdb;
			m_pCmd->CommandText = _bstr_t(m_strQuery);
			m_pCmd->CommandType = adCmdStoredProc;
			m_pConnection->CursorLocation = adUseClient;
			
			m_pRecordset = m_pCmd->Execute(NULL, NULL, adCmdText);
		}
		else
		{
			TRACE( "Unknown parameter. %d", nOption);
			return FALSE;
		}
	}
	catch(_com_error &e)
	{
		dump_com_error(e);
		return FALSE;
	}

	return m_pRecordset != NULL;
}

BOOL CADORecordset::Open(LPCTSTR lpstrExec, int nOption)
{
	ASSERT(m_pConnection != NULL);
	ASSERT(m_pConnection->GetState() != adStateClosed);
	return Open(m_pConnection, lpstrExec, nOption);
}

BOOL CADORecordset::GetFieldValue(LPCTSTR lpFieldName, double& dbValue)
{	
	double val = (double)NULL;
	_variant_t vtFld;
	
	try
	{
		vtFld = m_pRecordset->Fields->GetItem(lpFieldName)->Value;
		switch(vtFld.vt)
		{
		case VT_R4:
			val = vtFld.fltVal;
			break;
		case VT_R8:
			val = vtFld.dblVal;
			break;
		case VT_DECIMAL:
			//Corrected by Jos