Subject | Re: [firebird-support] Re: Why NULL <> NULL ? |
---|---|
Author | Kjell Rilbe |
Post date | 2006-05-18T14:42:07Z |
jasajona wrote:
evaluates to null (unknown). It makes a lot of sense.
of exceptions EVERYWHERE in close to ALL databases IN THE WHOLE WORLD.
condition, you want to get those records that you KNOW fulfil the
condition. You certainly don't want those that you KNOW DON'T. THose
records you don't know either way, you'd better make sure you know, for
example by using coalesce, or you'd better not get them, because you
wouldn't know what you get.
Kjell
--
--------------------------------------
Kjell Rilbe
Adressmarknaden AM AB
E-post: kjell.rilbe@...
Telefon: 08-761 06 55
Mobil: 0733-44 24 64
> --- In firebird-support@yahoogroups.com, Lucas Franzen <luc@...> wrote:You don't know either way, and that's exactly why the comparison
>
>>So your conclusion is that we both have the same amount of money in
>>our wallets, since we both have NULL....
>
> How do you know that we have not equal amount? :)
evaluates to null (unknown). It makes a lot of sense.
> In this caseNo, that wouldn't be useful at all, because you'd have to handle LOADS
> exception would be logical way to react to such situation.
of exceptions EVERYWHERE in close to ALL databases IN THE WHOLE WORLD.
> False - isThink of it this way: if you ask for records that fulfil a certain
> also answer, I had to swap statements of "then" and "else".
condition, you want to get those records that you KNOW fulfil the
condition. You certainly don't want those that you KNOW DON'T. THose
records you don't know either way, you'd better make sure you know, for
example by using coalesce, or you'd better not get them, because you
wouldn't know what you get.
Kjell
--
--------------------------------------
Kjell Rilbe
Adressmarknaden AM AB
E-post: kjell.rilbe@...
Telefon: 08-761 06 55
Mobil: 0733-44 24 64