TNS Packet writer failure and end-of-file on communication channel

Question

Hello Sir/Mam,
I m working on oracle server 9i. when i insert data into Blob,Nclob,Clob field which is larger than 4KB, this message occur everytimes.(TNS Packet writer failure or end-of-file on communication channel).
Can u tell me why this happen when i insert large data from 4KB.
I m using oledb to insert data into a table.if datasize is less than 4 KB ,its easily insert.
My Code Module is this
BOOL CconnectivityDlg::OpenOracleFile()
     BOOL bResult=FALSE;
     bFile = FALSE;
     dwFileSize = 0;
     CString csVirtualPath;      
     CFileDialog dlg(TRUE);
     if(dlg.DoModal()==IDOK)
          StrName = dlg.GetPathName();
     hFile1=CreateFile(StrName,GENERIC_READ|GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
                                   NULL,OPEN_EXISTING, NULL,NULL);
     unsigned int count =0;
          if(hFile1==INVALID_HANDLE_VALUE)
               if(count<5)
                    count++;
                    Sleep(1000);
               else
                    return bResult;
     DWORD dwHighPart,dwLowPart;
     dwLowPart = GetFileSize(hFile1,&dwHighPart);
     LARGE_INTEGER NewFilePointer;
     NewFilePointer.LowPart = dwLowPart;
     NewFilePointer.HighPart = dwHighPart;
     dwFileSize = NewFilePointer.QuadPart;     
     bFile     = TRUE;
     bResult = TRUE;     
     if(hFile1)
          CloseHandle(hFile1);
          hFile1 =NULL;
     return bResult;
BOOL CconnectivityDlg::CreateConnection()
     BOOL bResult = FALSE;     
     CString Count,strFileSaveName;
     Count.Empty();
     strFileSaveName.Empty();
     unsigned int nCounter = 0;     
repeat:     
     if(!AfxOleInit())
          return FALSE;
     m_pConn.CreateInstance (__uuidof(Connection));
     CString strConn ;
     strConn.Empty();
     m_pConn->CursorLocation = adUseClient;
     strConn     =_T("Provider=MSDAORA;OSAuthent=1;Data Source =LOVE;Connect as =SYSDBA;");
     try
          m_pConn->Open(_bstr_t(strConn),_bstr_t("system"),_bstr_t("system"),adConnectUnspecified);
          bResult = TRUE;
     catch(_com_error& e)
          CString sBuff = GetErrorDescription(e);
          AfxMessageBox(sBuff);
          return 0;          
     catch(...)
          AfxMessageBox(_T("UnknownError"));
          return 0;
     m_pCom.CreateInstance(__uuidof(Command));
     try
          m_pCom->ActiveConnection = m_pConn;
     catch(_com_error& e)
          CString sBuff = GetErrorDescription(e);
          AfxMessageBox((sBuff));          
     catch(...)
          AfxMessageBox(_T("UnknownError"));
     return bResult;
CString CconnectivityDlg::insertimage()
     CString Query,ColmnName;
     Query.Empty();
     ColmnName = _T("FIRST");//Coloumn Name
     Query = _T("insert into SINGLE(FIRST) values (?)"); //Table in which i want to insert data of Nclob type.
     hFile1 = CreateFile(StrName,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);//File from i read the data to insert into nclob field
     DWORD dwHighPart,dwLowPart;
     dwLowPart = GetFileSize(hFile1,&dwHighPart);
     LARGE_INTEGER NewFilePointer;
     NewFilePointer.LowPart = dwLowPart;
     NewFilePointer.HighPart = dwHighPart;
     dwFileSize = NewFilePointer.QuadPart;     
     BYTE *ImageData = new BYTE[dwFileSize+2];
     memset(ImageData,0,dwFileSize+2);
     BOOL bRead = ReadFile(hFile1,ImageData,dwFileSize,&dw,NULL);
     VARIANT varChunk;
     long lngOffset=0;
     UCHAR chData;
     SAFEARRAY FAR *psa = NULL;
     SAFEARRAYBOUND rgsabound[1];
     rgsabound[0].lLbound=0;
     rgsabound[0].cElements=dwFileSize;
     psa = SafeArrayCreate(VT_UI1,1,rgsabound);
     HRESULT hr;
     while(lngOffset < (long)dwFileSize)
          chData = ((UCHAR*)ImageData)[lngOffset];
          hr = SafeArrayPutElement(psa,&lngOffset,&chData);
          lngOffset++;                                        
     lngOffset     = 0;
     varChunk.vt=VT_ARRAY|VT_UI1;
     varChunk.parray=psa;
          try
          m_pCom->Parameters->Append(m_pCom->CreateParameter(_bstr_t(ColmnName),adLongVarWChar,adParamInput,(ADO_LONGPTR)dwFileSize,varChunk));
          VariantClear(&varChunk);
     catch(_com_error& e)
          CString sBuff = GetErrorDescription(e);
          AfxMessageBox(sBuff);
     if(ImageData)
          delete[] ImageData;
          ImageData = NULL;
     try
          m_pCom->CommandText=_bstr_t(Query);
          m_pConn->CursorLocation = adUseClient;
          m_pCom->CommandTimeout=0;
          m_pCom->Execute(NULL,NULL,adCmdText);
     catch(_com_error& e)
          CString sBuff = GetErrorDescription(e);
          AfxMessageBox(sBuff);
     return 0;
CString CconnectivityDlg::GetErrorDescription(_com_error& e)
bstrt bstrSource(e.Source());
bstrt bstrDescription(e.Description());
_TCHAR szTemp[1024];
CString strInfo ;
wsprintf(szTemp, _T("Message : %s\n"), e.ErrorMessage());
strInfo = szTemp;
wsprintf(szTemp, _T("Code : 0x%08lx\n"), e.Error());
strInfo += szTemp;
wsprintf(szTemp, T("Source : %s\n"), bstrSource.length() ? (LPCTSTR)bstrSource : T("null"));
strInfo += szTemp;
wsprintf(szTemp, T("Description : %s\n"), bstrDescription.length() ? (LPCTSTR)bstrDescription : T("null"));
strInfo += szTemp;
     CString str     =     strInfo;
     if(str.Find(_T("not a valid password"),0) > 0)
          strInfo     =     _T("File is password protected") ;
return strInfo;
}

Answer 1

user7728510 wrote:
Hi,
for what i know, MSDAORA provider doesn't support Oracle data types introduced since <font face="tahoma,verdana,sans-serif" size="1" color="#000">version</font> 8, as CLOB, BLOB and so on, so i think that it uses varchar2 up to the 4k limits and then causes this error.
Have you tried with the OraOLEDB.Oracle.1 provider instead?Nice writing, Thanks for your explanation!