My 2 cents worth.

If one specifies a default value of 0 in an IBO control then it should be
impossible to have a NULL value sent to the server by IBO no matter what the
user does (other than removing the default value or setting a property
UseDefaultValue to False).

If the IBO control does not do this then it is indeed a significant flaw.

Raymond

Eric Handbury wrote:

>
> --- In IBObjects@y..., "Marco Menardi" <mmenaz@l...> wrote:
> > Well, you are right in what you say, but, only with things
> organized
> > like yours.
> > I don't full understand the logic of your application.
> > In similar circumstances, I let the field having the NULL value,
> that
> > means "no key is here to link to a lookup table". You, on the
> > contrary, want to force values have 0 in this case (maybe because
> null
> > are hard to manage?).
> > A part from adding code to the client side, you can just put
> as "non
> > required" the field attribute, and force the 0 value in
> insert/update
> > triggers in the database.
>
> But this means that I have to write code for every LookupCombo key-
> field in every trigger to force this value to 0 if its NULL. This is
> the same as having all the code in the BeforePost events which is
> alot of work, and can result in alot of bugs.
> Its much easier for IBO to use the DefaultValue specified for that
> field. When you think about it, it is wrong for IBO to take a
> default action which is not configurable by the developer. I have
> told IBO that, in the absence of a real value, I want that key-field
> to be 0, and IBO should honour that when the user hits the DEL
> button on the LookupCombo.
>
> > If your modifications were included, how can the user set the
> field to
> > null? (canc will set to a default value...)
>
> But I would never want my key-fields to be NULL. I use Generators
> for all my keys so storing a NULL into a integer field is
> semantically incorrect. NULL is not a proper integer value.
>
> > Put a table of people and a field of "favourite book" that lookups
> > onto the books table. The default value is the the most lended
> book of
> > the library.
> > If a person has no "favourite book" you have to set the field to
> null.
> > It would be really bad having a "fake" book with the title "NO
> ONE" in
> > the books table...
> > How would you solve this?
>
> I use the DefaultValue KEYVALUE=0. This means that no masterkey
> matches this value so no 'favourite book' is displayed.
>
> Eric.
>
>
> ___________________________________________________________________________
> 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 !
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

--
Raymond Kennington
Programming Solutions
W2W Team B