Re: Examples of SQL anomalies?
Date: Tue, 8 Jul 2008 01:04:49 -0700 (PDT)
> Nulls are often but not exclusively used to mean unknown value. Failure to distinguish between different uses of null is the basis of most of these, rather pointless, arguments. <
Not that I would expect a change in the standard for these things, but wouldn't it be better to have two different markers for "no data" such as:
- NULL for "unknown yet, but should have a value lateron" which behaves like 1 + NULL + 1 = NULL
- N/A for "not applicable" what will be omitted in any expression and function such as 1 + N/A + 1 = 2
Normally a database should be designed a way N/A can not occurr (the column should not be there), but having this would give the possibility to use it where needed and to clear up the inconsistent behaviour, I think.
Philipp Post Received on Tue Jul 08 2008 - 03:04:49 CDT