Subject Re: Lookupcombobox question
Author Johan Kotze

Thanx for the help. I have foreign keys defined in the database that
will prevent the modelname from changing or deleting. I will try your
solution as soon as I get back to the office.


Johan Kotze

--- In IBObjects@y..., Helen Borrie <helebor@d...> wrote:
> At 02:47 PM 06-07-01 +0000, you wrote:
> >Geoff
> >
> >I have been using IBO for a while and I am able to get the
> >lookupcombo to work when the "lookup dataset" has two fields: a
> >field and a description field. Then I have no problems. The
> >here is that the "lookup dataset" has only one field and this is
> >field that must go to the "master database". I also want to
> >the field in the "master database" in a grid as well. I have tried
> >your enhanced lookupcombo as well, but I am sure my problem is in
> >keylinks property. My Keylinks and KeyDescLinks looks like this:
> >
> >
> >Is this correct ?
> Almost...
> Take out the lookup table identifier from the keylinks string.
> And you won't need KeyDescLinks. That is used in the embedded
lookupcombo when the description field has to be updated as a result
of the parent dataset being scrolled. The normal purpose of lookup
keys is to provide a key that points to a matching primary key in the
lookup dataset. By redundantly storing the model name in the parent
dataset, the parent has no need to search for an updated description.
> The downside to this approach is that, if the model name changes in
the underlying lookup table, the value stored in the table will no
longer be valid. Even just correcting a typo in the Model table will
render all lookup refs to that record invalid. It is much sounder
RDBMS practice to normalise out such redundancies and use genuine
atomic keys for relationships.
> Regards,
> Helen
> All for Open and Open for All
> InterBase Developer Initiative ยท
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