> with qryUpdate do
> begin
> IB_connection := cnIBImport;
> Close;
> SQL.Clear;
> SQL.Add('SELECT rdb$field_name as Field ');
> SQL.Add(' FROM rdb$relation_fields ');
> SQL.Add('where rdb$relation_name = :TableName');
> => ParamByName('TableName').AsString := TableName;
> Prepare;
> Open;
> ...
>
> end;
>
> I call this routine many times in my data update wizard (for each table)
> and so far have not had this error ever come up. I use it for creating
> the SQL for Select, Insert and Update.
>
> The "ParamByName('TableName').AsString := TableName;" is what causes the
> error.
>
> The same code if run as a query against the same table inside IB_Expert
> or IB_SQL runs fine, without error.

Had a similar problem a while ago: if the field is defined as e.g.
varchar(30) and you try to pass a stringvalue via parameters that
happens to be larger than 30 charcters: error (forgot which error was
reported). Also in IBExpert the query went fine, also in IBObjects the
query ran without problems. Spying the traffic, I saw these programs
trimmed the values passed to the parameters.

With ZEOS database objects: error.

Maybe it is not the same as your problem, but it really sounded familiar....

Regards,
John'