Re: Useful Oracle books - C.J. Date theory vs. practicality

Lex de Haan said,on my timestamp:29/05/2004 5:29 PM:

> the IS NULL operator is two-valued,
> so it would never show the "desired" behavior for this experiment...
> 'string' IS NULL always evaluates to FALSE, and '' IS NULL evaluates to TRUE
> (which is quite unfortunate, but that's another discussion)

I see your point, of course. Otherwise it's harder to show the problem.

But the thing that bugs me is: isn't the Oracle (and presumably others db) solution of "IS NULL" a good solution?

I mean: avoid the TRUE/FALSE/NULL logic problem without re-defining the entire IF?

Is there something wrong with:
IF (<var> is NOT NULL) then

   IF(<var> = 'something') then do_this
   ELSE do_that
   END IF;
ELSE do_nothing;
END IF;
other than the obvious verbosity/style of writing?

(says he who had to code something like this ad-infinitum in a project 3 years ago...)

-- 
Cheers
Nuno Souto
in sunny Sydney, Australia
dbvision_at_optusnet.com.au
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