Re: 3vl 2vl and NULL

From: Jonathan Leffler <jleffler_at_earthlink.net>
Date: Mon, 05 Dec 2005 08:04:22 GMT
Message-ID: <awSkf.175$FP6.49@newsread2.news.pas.earthlink.net>

michael_at_preece.net wrote:
> David Cressey wrote:

>> [...]

> Here's the thing: If you have a table with an unlimited number of rows
> and a limited number of columns then it is understood that the number
> of tuples in the table is rows*columns. True?

Not for any definition I've heard of... Did you mean 'values' instead of 'tuples'? "The number of values in the table is rows * columns".

> And every tuple must have a value.

Yes - for tuples as tuples, or tuples misreferenced when values was intended. Further, the component values in each tuple must have a value.

> And if we don't have a actual value for one or more tuples we
> have to use NULL to represent the fact that there is no value.

IMO, this is so confused between tuples and values that there is no value in debating further... :-(

I'm not going to consider the rest of the posting - I would need to understand this much of it before going any further, and as you can tell from my comments, I don't understand what you've written.

Would you be willing to try again?

-- 
Jonathan Leffler                   #include <disclaimer.h>
Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com
Guardian of DBD::Informix v2005.02 -- http://dbi.perl.org/

Received on Mon Dec 05 2005 - 02:04:22 CST