🚀 go-pugleaf

Is your field defined as varbinary(8000)? If so, ADO Express will bind it as
TVarBytesField that is not TBlobField.

Try get

ADOQuery->Fields->Field[0]->Value

or even

ADOQuery->Recordset->Fields->Item[0]->Value

and look at its type. If it is not VT_BSTR or array type, you can not use
TADOBlobStream.

//------------------------------------------
Regards,
Vassiliev V. V.
http://www.managed-vcl.com - using .Net objects in Delphi for Win32 +
ADO.Net
http://www.oledbdirect.com - The fastest way to access MS SQL Server,
MS Jet (Access) and Interbase (through OLEDB)

"kdl" <me@isp.net> �������/�������� � �������� ���������:
news:4085a472@newsgroups.borland.com...
> Thanks for the response.  At first glance,it looks exactly like my line of
> code (stream = new TADOBlobStream....) that generated the original
"Invalid
> Variant Operation" error that prompted the question.  I will look at it
more
> closely however... Perhaps I need to check with the Database guys that
> generated the database to make sure the data is valid. I do not know how
> that would cause the error message though.
>
> *** My Original ***
> -------------------------------------------------------------------------
>     TADOBlobStream *Stream;
>
> //Crashes on this line.  I have tried many variations
> including"CreateBlobStream"  and ->Fields[n] with no success.
>     Stream = new
>
TADOBlobStream((TBlobField*)adoTraceDetailsDataSet->FieldByName("TraceArray"
> ) ,bmRead);
> --------------------------------------------------------------------------
>
> Thanks again for the input,
> kev
>
>
> <Mike Crapo> wrote in message
> news:va5b805kaktfpiju4sredkjm88tdgcb5ei@4ax.com...
> > Kev.
> >
> > Here is some code on how I get a blob out of a database.  It has been
> > changed to make it more generalized, but you should be able to see the
> > meathods.
> >
> > //Connect to database
> > TADOQuery *Query = new TADOQuery(0);
> > TADOBlobStream *Stream;
> > Query->SQL->Add("SELECT TraceDetails FROM TraceTable Where TraceID =
> > 1");
> > Query->Connection = ADOConnection; //Or whatever you ado connection
> > is.
> > Query->CursorType = ctStatic;
> > Query->CacheSize = 10000;
> > Query->CursorLocation = clUseClient;
> > Query->LockType = ltReadOnly;
> > Query->Open();
> > if(Query->RecordCount > 0)
> >   {
> >   Stream = new
> > TADOBlobStream((TBlobField*)Query->Fields->Fields[0],bmRead);
> >   Stream->Position = 0;
> >   Stream->SaveToFile("Test.tmp");//Do whatever you want to do with the
> > stream.
> >   delete Stream; //Delete Stream before closing conection
> >   }
> > delete Query;
> >
> >
> > Mike
> >
> > On Tue, 20 Apr 2004 15:17:35 -0500, "kdl" <me@isp.net> wrote:
> >
> > >TraceDetails
> >
>
>