>
> Yes, look at all your ParamByName, Params, FieldByName and Fields
> references, where you use the ".Value" method and replace any

problem ones

> with ".AsWhatever", i.e. explicit casting.

See I have just made a little test appl.
In this I have only two TIBOQuerys.
Then first does:

Select * from Farver;


The second does:

Select * from Farver_Detail where Navn = :Navn;

In my program is do this on FormShow:

IBODatabase1.Open;
IBOquery1.Open;
IBOquery2.Open;


When opening the second I get the above error.

If I instead does this on OnDataChange on the first TIBOQuerys
datasource it works:

IBOQuery2.Close;
IBOQuery2.ParamByName('Navn').AsString := IBOQuery1.FieldByName
('Navn').AsString;
IBOQuery2.OPen;


Is this the way I should go, or can I do something to make IBO behave
the same way as standard TQuery comp ?


Everywhere in my originally program I ALWAYS uses AsWhatEver when I
use the ParamBy... and the FieldBy...

Michael

>
> Another source of this problem could be NULLs being treated as

values. IBO

> doesn't convert nulls to values unless you explicitly tell it to.

This is

> fairly complicated to do with TIBOQuery so it's better to test the

column

> object's IsNull property before trying to read a Value from it.
>
> Helen