VC++中ADO方式操作数据库之有关“datetime”字段的操作

[cpp] 
直接上代码： 
[cpp] 
void CADOConDlg::OnButton1()  
{ 
    // TODO: Add your control notification handler code here 
    HRESULT hr; 
    CString strSql; 
    _ConnectionPtr m_pConnection; 
    _RecordsetPtr m_pRecordset; 
    try 
    { 
        //create the SQL service object  
        hr = m_pConnection.CreateInstance(__uuidof(Connection)); 
        ASSERT( SUCCEEDED(hr) ); 
        strSql.Format("%s","Provider=SQLOLEDB;server=xxx;database=xxx;UID=xxx;PWD=xxx"); 
        m_pConnection->ConnectionString = (_bstr_t)strSql; 
        hr = m_pConnection->Open("","","",adConnectUnspecified); 
        ASSERT( SUCCEEDED(hr) ); 
        //create the record set object for write 
        hr = m_pRecordset.CreateInstance(__uuidof(Recordset)); 
        ASSERT( SUCCEEDED(hr) ); 
 
        CString strCurrentTime; 
        strSql.Format(_T("select * from 。。。='。。' ")); 
        m_pRecordset->raw_Close(); 
        m_pRecordset->CursorLocation = adUseClient; 
        hr = m_pRecordset->Open((_variant_t)strSql, m_pConnection.GetInterfacePtr(), adOpenKeyset, adLockOptimistic, adCmdText); 
         
        SYSTEMTIME sys;   
        GetLocalTime( &sys );   
        strCurrentTime.Format(_T("%d-%d-%d %d:%d:%d"),sys.wYear,sys.wMonth,sys.wDay,sys.wHour,sys.wMinute,sys.wSecond); 
        _variant_t varTime = (LPCTSTR)strCurrentTime; 
 
        m_pRecordset->Update("datetime",(_variant_t)(COleDateTime)varTime); 
//      m_pRecordset->Update("datetime",(_variant_t)(COleDateTime)sys); 
        //COleDateTime只精确到秒级 
        //查下MSDN就知道，其实(COleDateTime)强转的类型可以很多 
        AfxMessageBox("successful"); 
 
        CString strTimeGet; 
        _variant_t varTimeGet; 
        COleDateTime oleTimeGet;   
        SYSTEMTIME sysTimeGet; 
        varTimeGet=m_pRecordset->GetCollect("datetime"); 
        if (varTimeGet.vt!=VT_NULL) 
        { 
            //strTimeGet=varTimeGet.bstrVal;//此路不通 
            oleTimeGet=(COleDateTime)varTimeGet; 
            VariantTimeToSystemTime(oleTimeGet,&sysTimeGet); 
            strTimeGet.Format(_T("%d-%d-%d %d:%d:%d"),sysTimeGet.wYear,sysTimeGet.wMonth,sysTimeGet.wDay, 
                sysTimeGet.wHour,sysTimeGet.wMinute,sysTimeGet.wSecond); 
            AfxMessageBox(strTimeGet); 
        } 
    } 
    catch (_com_error e) 
    { 
        //CWnd::MessageBox(e.ErrorMessage(), "error DB select read!", NULL); 
        AfxMessageBox(e.Description()); 
    } 
}