If possibly applicable, by default, IBO returns a ftString if StrLen <= 255,
else a ftMemo. This can be overridden in IB_Session.pas

----- Original Message -----
From: "Ramil" <khabibr@...>
To: <IBObjects@yahoogroups.com>
Sent: Sunday, April 06, 2008 10:57 PM
Subject: Re[2]: [IBO] Strange SQL results with large text field


> Hello Robert,
>
> I can not reproduce your situation.
>
> I have added the field "Stock0015" to the IBO sample database MASTER
> (IBO\Samples\TDataset\Filters):
>
> ALTER TABLE MASTER
> ADD Stock0015 VarChar(2048);
>
> I have filled the table with large texts mixed up with nulls.
> And I execute this:
>
> procedure TForm1.Button2Click(Sender: TObject);
> begin
> while not qryMaster.eof do
> begin
> if (qryMaster.FieldByName('Stock0015').AsString <> '')
> and qryMaster.FieldByName('Stock0015').IsNull then
> ShowMessage('Here I am!');
> qryMaster.Next
> end;
> end;
>
> What version of IBO and Firebird you have used?
> Can you send me database or a little demo-program with source that
> reproduce this situation?
>
>
>>
>>
>>
>>
>>
>> Hi Helen
> >> Well, the place to start would be to look at the code where you pick up
> >> the text from the current IBODataset row to pass it to the ADOQuery
> >> parameter. Of special interest would be whether you are relying on
> >> some record number property that isn't valid for an IBO set...or where
> >> you might be treating null and empty string somewhere as though they
> >> were equivalent.
> >>
> >>
>>
>> There is no code ! The IBOQuery result fields have the same as the
>> parameters in the TADOQuery. The TADOQuery is set to use the TIBOQuery
>> as the .Datasource. Sorry I should have been clearer.
>>
>> After loading master and source (IBO AND ADO respectively) SQL
>> statements from a script. I loop through something like
>>
>> IBOQuery.first;
>> while (IBOQuery.Eof = False) do begin
>> ADOQuery.ExecSQL;
>>
>> IBOQuery.Next;
>> end;
>>
>> I thought the problem was with the ADO Query but I put a break point on
>> before the .ExecSQL and used the 'Evaluate/Modify' tool in Delphi to
>> view the data in the IBOQuery at that point.
>> FieldByName('Stock0015').AsString <> '' but
>> FieldByName('Stock0015').IsNull = True !
>>
>> Sorry about using Delphi syntax for those non Delphi people.
>>
>> Hope that makes the problem clearer.
>>
>> Rob Martin
>> Software Engineer
>>
>> phone +64 03 377 0495
>> fax +64 03 377 0496
>> web www.chreos.com
>>
>> Wild Software Ltd
>
> --
> Best regards,
> Ramil R. Khabibullin khabibr@...
>
>
> ------------------------------------
>
> ___________________________________________________________________________
> IB Objects - direct, complete, custom connectivity to Firebird or
> InterBase
> without the need for BDE, ODBC or any other layer.
> ___________________________________________________________________________
> http://www.ibobjects.com - your IBO community resource for Tech Info
> papers,
> keyword-searchable FAQ, community code contributions and more !
> Yahoo! Groups Links
>
>
>