C / C++ / MFC

struct RS_FILE
{
	long	m_l_FileID;
	CString m_cs_FileName;		// This will get set by the DB functions for the following class.
	CLongBinary	m_lb_FileData;	// This will get set by the DB functions for the following class.

bool DB_File_Insert(CDatabase* db, RS_FILE& rs_file, const std::string& s_file_fullname, CErrorHandler& eh)
{
	bool b_ret = true;
	HGLOBAL hGlobal = NULL;
	try
	{
		CRecordSetFile rs(db);
		if (rs.Open() == FALSE)
		{
			eh.Initialize();
			eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Failure to open the file record set to insert a new record.");
			return false;
		}

		rs.AddNew();
		rs.m_rs_file = rs_file;

		// Open the file.
		CFile cf;
	    CFileStatus	fileStatus;
		if (cf.Open(s_file_fullname.c_str(), CFile::modeRead) == FALSE)
		{
			eh.Initialize();
			eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Failure to open the file '%s' for inserting into the database.",s_file_fullname.c_str());
			b_ret = false;
			goto LabelRecordSetFileClose;
		}
		if (cf.GetStatus(fileStatus) == FALSE)
		{
			eh.Initialize();
			eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Failure to get the status of the file '%s' after opening it to insert into the database.",s_file_fullname.c_str());
			b_ret = false;
			goto LabelFileClose;
		}

		rs.m_rs_file.m_cs_FileName = cf.GetFileName();
		rs.m_rs_file.m_lb_FileData.m_dwDataLength = fileStatus.m_size;

		hGlobal	= GlobalAlloc(GPTR,fileStatus.m_size);
		if (hGlobal == NULL)
		{
			eh.Initialize();
			eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Failure to allocate the specified number of bytes '%ld' for copying the file '%s' into for storing into the database.",fileStatus.m_size,s_file_fullname.c_str());
			b_ret = false;
			goto LabelFileClose;
		}

		rs.m_rs_file.m_lb_FileData.m_hData = GlobalLock(hGlobal);

		cf.ReadHuge(rs.m_rs_file.m_lb_FileData.m_hData,fileStatus.m_size);

		rs.SetFieldDirty(&rs.m_rs_file.m_lb_FileData, TRUE );
		rs.SetFieldNull(&rs.m_rs_file.m_lb_FileData, FALSE );

		if (rs.Update() == FALSE)
		{
			eh.Initialize();
			eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Failure to insert the new record into the database.");
			b_ret = false;
		}

	    GlobalUnlock(hGlobal);

LabelFileClose:
		cf.Close();

LabelRecordSetFileClose:
	    rs.Close();
	}
	catch(CDBException* e1)
	{
		eh.Initialize();
		eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Database Error: %s",e1->m_strError);
		return false;
	}
	catch(CException* e2)
	{
		eh.Initialize();
		char sz_error [MAX_PATH] = "";
		e2->GetErrorMessage(sz_error,sizeof(sz_error));
		eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Database Error: %s",sz_error);
		return false;
	}
	catch(...)
	{
		eh.Initialize();
		eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Database Error: Unknown.");
		return false;
	}
	return b_ret;
}

// This function seems to work fine.
bool DB_File_GetID(CDatabase* db, const long& l_id, RS_FILE& rs_file, CErrorHandler& eh)
{
	try
	{
		CRecordSetFile rs(db);
		rs.m_strFilter.Format("[FileID] = %ld",l_id);
		if (rs.Open() == FALSE)
		{
			eh.Initialize();
			eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Failure to open the record set to get the file id '%ld'.",l_id);
			return false;
		}
		rs_file = rs.m_rs_file;
		rs.Close();
	}
	catch(CDBException* e1)
	{
		eh.Initialize();
		eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Database Error: %s",e1->m_strError);
		return false;
	}
	catch(CException* e2)
	{
		eh.Initialize();
		char sz_error [MAX_PATH] = "";
		e2->GetErrorMessage(sz_error,sizeof(sz_error));
		eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Database Error: %s",sz_error);
		return false;
	}
	catch(...)
	{
		eh.Initialize();
		eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Database Error: Unknown.");
		return false;
	}
	return true;
}

bool RS_FILE::WriteFile(const std::string& s_folder, CErrorHandler& eh)
{
    std::string s_temp_folder = s_folder;
    if(s_temp_folder.length() == 0)
    {
        eh.Initialize();
        eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Failure to write the file to a folder because the folder is not specified.");
        return false;
    }

    if (s_temp_folder[s_temp_folder.length()-1] != '\\')
        s_temp_folder += "\\";

    std::string s_file = ssprintf("%s%s",s_temp_folder.c_str(),m_cs_FileName);

    CFile cf;
    if (cf.Open(s_file.c_str(),CFile::modeCreate|CFile::modeWrite) == FALSE)
    {
        eh.Initialize();
        eh.Set(__FUNCTION__,__FILE__,__LINE__,EHTYPE_ERROR,"Failure to open and create the file '%s' to write data to.",s_file.c_str());
        return false;
    }
    LPSTR buffer = (LPSTR)GlobalLock(m_lb_FileData.m_hData);
    cf.WriteHuge(buffer,m_lb_FileData.m_dwDataLength); // Failure here.
    GlobalUnlock(m_lb_FileData.m_hData);
    cf.Close();
    return true;
}

void CFile::Write(const void* lpBuf, UINT nCount)
{
	ASSERT_VALID(this);
	ASSERT(m_hFile != (UINT)hFileNull);

	if (nCount == 0)
		return;     // avoid Win32 "null-write" option

	ASSERT(lpBuf != NULL); // For some reason lpBuf is NULL