It's better to use "null" values or "0" and "" ?

thank you

On Sun, 20 Jun 2004 10:20:35 +0200, Utopian [ FTa ] wrote:

>It's better to use "null" values or "0" and "" ?
>
>thank you
>

Hi Utopian,

You'll probably get different answers to this question. Many people advise
against using NULLs, because some of the consequences of having NULL in a
database are not well understood by many programmers.

I think you should use NULLs to indicate missing information. If you
combine attributes that are not directly related into one table, you must
expect that there will be occasions that not all information can be stored
(for whatever reason). Some people choose to store special values (like
zero, the blank string or 1/1/1900) to indicate this, trying to avoid the
"problems" they perceive with NULL. Instead, they only hide these
problems, and add some extra problems to boot.

An RDBMS comes with a special instrument to deal with unknown values. That
special instrument is NULL. It's just silly to avoid this instrument and
make up your own instead, just because some programmers don't understand
how three-valued logic works. Much better would be to teach these
programmers to do their job properly.

Of course, regardless of whether unknown values are stored as NULL or as
special values, it's always best to allow as little unknown values as
possible.

Best, Hugo
--

(Remove _NO_ and _SPAM_ to get my e-mail address)

Ok. Thank you.
I think i continue to use "null" values ;-)

>> It's better to use "null" values or "0" and "" ? <<

Where to start? Well, the double quote mean that you have a user
created data element name; and NULLs are not values. I think that if
you knew the bare foundations of SQL and a little grammar, you might
have meant to post:

>> Is it better to use NULLs, or to use 0 and ''? <<

Now the question is silly and not incoherent. Now we have NULL, a
numeric zero and an empty string.

The answer is "use for what?" Which is better- a screw or a basket
ball? Does your application and data model require a value or a NULL?