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

On 17 Nov 2005 16:57:25 -0800, michael_at_preece.net wrote:

>Just FYI - on Pick

 (snip)

Hi Mike,

I entered this thread because someone who was reading up on SQL appeared to have trouble grasping the definition of Null in SQL.

I'll gladly admit that I know nothing about Pick, and have no need to change that. I'm also not prepared to involve in a DSW between Pickies and SQL-addicts.

(snip)
>> HOW a Null is represented is irrelevant. WHAT it represents is what
>> matters.
>>
>
>Fair enough. I simply believe NULL is actually nothing. I think it
>should be respresented as nothing.

What you believe and think is not going to change the definitions used in the SQL standard. Null is defined as a marker to mark the absence of a value, so that's what it is in a SQL database. (Actually quite close to what you believe NULL to be, as a matter of fact - but not quite the same. If you want to learn SQL, you'll have to get used to a new definition of Null).

> Something that is unknown is
>something else entirely, and can/should be represented in an entirely
>different way. Whatever it is it's not NULL - not in my book, or my
>dictionary, or, apparently, in the ANSI standard.

I fully agree with that. And what's more important - so does the ANSI committee.

> Just in SQL. Am I
>wrong?

You are wrong about SQL's definition of null. As I already said in my first post: in SQL, null IS NOT the same as unknown.

Best, Hugo

-- 

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