nulls are tuff to get but you need to think of them as nothing, not a blank but
as nothing, a void, zilch, no value exists and you can't do comparisons of
something to nothing. In database world, spaces and blanks are something while
nulls are nothing. So 'Hello' <> null means Hello <> no value to evaluate and
if there is nothing to evaluate, the comparisons won't work hence why there are
specific null comparisons...
If Hello is not null and Hello=Hello, which means If hello is something and
hello=hello
If Hello is null or Hello<>good bye, If hello is nothing or hello<>good bye
Okay so my $.02...
now I understand nulls are challenging to comprehend and for most there is a
big push to eliminate null values but a null isn't a bad thing because it is
nothing it takes up little (if no) memory and for me, does serve a purpose to
let me know if there has been any activity or not with data. just because
something isn't easily understood or it's true purpose to be self evident and
beneficial to me and causes a pain in the you know what if I don't understand
how to deal with it, shouldn't be a reason to eliminate it...kinda like a
Minnesota wood tick..I have no idea what's it good for, not sure if anything
feeds on it, hate picking them off, they're next to impossible to kill, and
pretty sure I'll end up with lymes disease one day but I won't avoid them
because I love the outdoors and would never advocate to eliminate them because
I'm sure they serve a purpose in some order of things. so like nulls, I have
educated myself and have no problem in applying procedures to reduce my risks
and still do what I need, and/or like, to do.....now if only it would stop
snowing because right now I'd like to go play with the ticks...BTW does anyone
know if emerging tulips can survive under a foot of snow for two weeks?!?
Have a Fabulous Day!
Rachael M.
Freelance Developer
www.DragonflyDevelopmentMN.com
----- Original Message -----
From: Marc
To: RBASE-L Mailing List
Sent: Friday, April 11, 2008 9:32 AM
Subject: [RBASE-L] - Re: EQNULL ON or OFF
This always reminds me of Who's on First, it makes your head spin.
But to my way of thinking and what I think would make sense to users
Hello is only = to Hello therefore <> to anything else
so with EQNULL ON or OFF the Pause statement should fire because
no matter what Hello can not be = to a blank field or a null or empty field
Hello can only be = to Hello
The same for <> Hello is = to only Hello therefore <> to everything else.
Am I nuts or just not getting this. Maybe my RBrain is set Off?
Marc
----- Original Message -----
From: [EMAIL PROTECTED]
To: RBASE-L Mailing List
Sent: Friday, April 11, 2008 8:31 AM
Subject: [RBASE-L] - Re: EQNULL ON or OFF
Marc:
For you, the danger would be to set it OFF right now without checking your
programs. If your programs were done with the assumption that eqnull was set
ON, then you better not change the setting. Here's the main difference:
set var vtext1 = 'hello', vtext2 text = null
if vtext1 <> .vtext2 then
pause 2 using 'they are not equal, so do something'
endif
if eqnull ON, then the pause would evaluate because it is able to compare a
null to a value. If you eqnull is OFF (which I believe the majority of us do),
then a null cannot be compared with anything and the pause would NOT evaluate.
Karen
Marc,
When EQNULL is on, R:BASE doesn't distinguish a null from a zero, so any
average calculations are screwy.
Bill
On Fri, Apr 11, 2008 at 8:41 PM, Marc <[EMAIL PROTECTED]> wrote:
After reading the other thread I got nervous about my EQNULL setting.
I have it set to ON, so now I am worried. I had a problem sometime back
and setting EQNULL ON fixed that problem so I just leave it on.
What are the dangers with it ON?
thanks
Marc
