Having problems with message search?
This is code that we used. It is quite old as we no longer use oo4o and prefer to use OCI directly.
The method is taken from a class that encapsulated this kind of functionallity. m_pDatabase is a member pointer to an ODatabase object.
BOOL CBlobHander::CreateFileFromBlob(LPCSTR pszTableName, LPCTSTR pszBlobField, LPCTSTR pszWhereClause, LPCTSTR pszFilename)
{
#ifdef _DEBUG
if (m_pDatabase && !m_pDatabase->m_Database.IsOpen())
{
MessageBox(NULL, "Can not Create File - Database Not Connected", "Error", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
#endif
{
#ifdef _DEBUG
if (m_pDatabase && !m_pDatabase->m_Database.IsOpen())
{
MessageBox(NULL, "Can not Create File - Database Not Connected", "Error", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
#endif
ODynaset dyn;
CString strSQL;
CString strSQL;
strSQL.Format("SELECT %s FROM %s WHERE %s", pszBlobField, pszTableName, pszWhereClause);
if (_BOOL(dyn.Open(m_pDatabase->m_Database, strSQL)))
{
if (_BOOL(dyn.Open(m_pDatabase->m_Database, strSQL)))
{
#ifdef _DEBUG
if (dyn.GetRecordCount() == 0)
{
MessageBox(NULL, "Can not find Object Record.", "Error", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
else if (dyn.GetRecordCount() > 1)
{
MessageBox(NULL, "Query returned more than one record. Can not update.", "Error", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
#endif
if (dyn.GetRecordCount() == 0)
{
MessageBox(NULL, "Can not find Object Record.", "Error", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
else if (dyn.GetRecordCount() > 1)
{
MessageBox(NULL, "Query returned more than one record. Can not update.", "Error", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
#endif
OBlob oblob;
dyn.GetFieldValue(0, &oblob);
dyn.GetFieldValue(0, &oblob);
#ifdef _DEBUG
if (oblob.IsNull() || (oblob.GetSize() == 0))
{
MessageBox(NULL, "Can not Create File - Blob is Empty.", "Error", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
#endif
if (oblob.IsNull() || (oblob.GetSize() == 0))
{
MessageBox(NULL, "Can not Create File - Blob is Empty.", "Error", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
#endif
unsigned char *buffer = 0;
try
{
fstream fs;
{
fstream fs;
fs.open(pszFilename, ios::out);
fs.setmode(filebuf::binary);
fs.setmode(filebuf::binary);
unsigned long size = oblob.GetSize();
// calculate an optimum buffersize of approximately 32k bytes
unsigned long optchunk = oblob.GetOptimumChunkSize();
unsigned int bufsize = ((int)(32768/optchunk)) *optchunk;
if (bufsize > size)
bufsize = size;
unsigned long optchunk = oblob.GetOptimumChunkSize();
unsigned int bufsize = ((int)(32768/optchunk)) *optchunk;
if (bufsize > size)
bufsize = size;
buffer = (unsigned char *)malloc(bufsize);
//By taking advantage of streaming we get the best performance
//and do not need to allocate a large buffer
//and do not need to allocate a large buffer
oblob.EnableStreaming(size);
short status= OLOB_NEED_DATA;
unsigned long amtread=0;
unsigned long amtread=0;
while(status == OLOB_NEED_DATA)
{
amtread = oblob.Read(&status, buffer, bufsize);
//if (status != OLOB_NODATA)
if (amtread == 0)
fs.write(buffer, bufsize);
else
fs.write(buffer, amtread);
}
{
amtread = oblob.Read(&status, buffer, bufsize);
//if (status != OLOB_NODATA)
if (amtread == 0)
fs.write(buffer, bufsize);
else
fs.write(buffer, amtread);
}
oblob.DisableStreaming();
fs.close();
}
catch(OException E)
{
CString strMsg;
strMsg.Format("%s Error: %s", E.GetFailedMethodName(), E.GetErrorText());
MessageBox(NULL, strMsg, "Error", MB_ICONINFORMATION | MB_OK);
}
}
catch(OException E)
{
CString strMsg;
strMsg.Format("%s Error: %s", E.GetFailedMethodName(), E.GetErrorText());
MessageBox(NULL, strMsg, "Error", MB_ICONINFORMATION | MB_OK);
}
if (buffer)
free(buffer);
return TRUE;
}
else
{
int n = dyn.ErrorNumber();
MessageBox(NULL, dyn.GetErrorText(), "Failed To Open Object Record", MB_ICONINFORMATION | MB_OK);
free(buffer);
return TRUE;
}
else
{
int n = dyn.ErrorNumber();
MessageBox(NULL, dyn.GetErrorText(), "Failed To Open Object Record", MB_ICONINFORMATION | MB_OK);
return FALSE;
}
}
}
}
From: Alaa Mostafa [mailto:alaa210@...]
Sent: 22 June 2004 06:04
To: oo4ole@yahoogroups.com
Subject: [oo4ole] How to use oo4o to save BLob ?[Scanned]
Hi all
used oo4ole with Visual C++ ,
How to save image (stored in BLOB data type ) Using OO4O ;
thanks
alaa
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