Re: Examples of SQL anomalies?

From: Philipp Post <Post.Philipp_at_googlemail.com>
Date: Tue, 8 Jul 2008 01:04:49 -0700 (PDT)
Message-ID: <b4fe18db-186b-4da3-aa7e-ae33403487ae@p25g2000hsf.googlegroups.com>


> 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.

brgds

Philipp Post Received on Tue Jul 08 2008 - 03:04:49 CDT

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