Re: So what's null then if it's not nothing?

From: mountain man <hobbit_at_southern_seaweed.com.op>
Date: Wed, 23 Nov 2005 08:19:31 GMT
Message-ID: <nCVgf.1564$ea6.741_at_news-server.bigpond.net.au>


"paul c" <toledobythesea_at_oohay.ac> wrote in message news:CIQgf.578722$tl2.426979_at_pd7tw3no...

> mountain man wrote:

>> "paul c" <toledobythesea_at_oohay.ac> wrote in message
>> news:OhPgf.573740$1i.24270_at_pd7tw2no...
>>
>>>Frank Hamersley wrote:
>>>
>>>>JOG wrote:
>>>>
>>>>
>>>>>michael_at_preece.net wrote:
>>>>>
>>>>>
>>>>>>"A value of the Boolean data type is either true or false. The truth
>>>>>>value of unknown is sometimes represented by the null value."
>>>>>>
>>>>>>Dodgy or what?! It would be better to use a large cumbersome robot
>>>>>>waving its arms about saying "does not compute" than to use null for
>>>>>>this.
>>>>>>
>>>>>>Mike.
>>>>>
>>>>>
>>>>>I for one _really_ hope some database corporate representatives are
>>>>>reading this thread, and take this feature into consideration for their
>>>>>future releases.
>>>>
>>>>
>>>>Errr...pardon me for being dense...but exactly what is the "feature" we
>>>>so desperately need?
>>>>
>>>>Cheers, Frank.
>>>
>>>I was trying to exercise restraint, but I guess I've gotten sucked in
>>>along with some smart people. puts me in good company, i suppose ...
>>>
>>>i don't understand why such a question ends up with so much space on the
>>>"databases.theory" newsgroup. is it because there is no such group as
>>>"comp.databases.practice.etc"?
>>
>>
>>
>> Its because the theory side of databases is lead at the moment
>> by a large hand waving robot called "The Pedagogy of the RM".
>> This practice (as most human concerns go) is self perpetuating
>> and has been at it in excess of 30 years.
>>
>> The problem is that evolution in the world external to the academic
>> vision of the relational model has not been matched by evolution
>> of the model, or evolution of its interfaces to other valid models
>> and ideas in the (information technology) environment.
>>
>> Technically, the NULL can mean a different thing
>
>
> "Techically" is yet another porridge word.

The technical implementation of the handling of null values within the different RDBMS and DBMS software vendors such as Microsoft, Oracle, IBM, etc are diverse, as are the various kinds of breakfast cereals.

>the basic motivation behind nulls seems to be that if you play with 
>language long enough, you end up convincing yourself that there are 
>syntactic nuances that somehow matter.


Basic motivations are diverse and may have nothing at all to do with language. For example Codd and Date have totally different "basic motivations behind nulls"

Pete Brown
www.mountainman.com.au Received on Wed Nov 23 2005 - 09:19:31 CET

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