Subject Re: [IBO] How to retrieve NULL from a LookupCombo?
Author Mario Zimmermann
--- In IBObjects@y..., "Geoff Worboys" <geoff@t...> wrote:
> > When the key field in the master table contains a value,
> > how can I remove the lookup key value from my master
> > table? The LookupCombo shows only valid records from
> > the lookup table. Is there any possibility to display
> > a configurable text (i.e. "<none>") in the LookupCombo
> > which inserts NULL into the master's table key field
> > when the user selects it?
> I am not certain I understand what you are looking for. When you
> delete the contents of the lookupcombo (select all the text and
> delete) then the lookup sets null and display blank. Is this not
> enough?

Oops, I never realized that this is possible. Works ok. However, I
don't think that this is very user friendly. I would prefer a "NULL
entry" in the lookup combo which the user can select. Before IBO, I
worked with RxLookupCombo which has a property "NullValue" where you
can set the lookup text for a NULL value.