Re: [BUGS] (null) != (null) ?

Todd Vierling <tv@pobox.com>

From: Todd Vierling <tv@pobox.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-bugs@postgreSQL.org
Date: 1999-10-26T14:41:52Z
Lists: pgsql-bugs
On Tue, 26 Oct 1999, Todd Vierling wrote:

: : NULL = NULL does not yield TRUE, it yields NULL.  For that matter,
: : NULL != NULL does not yield FALSE --- it yields NULL.  This is a
: : basic consequence of the semantics of NULL.

: It seems _extremely_ counter-intuitive, especially in cases where both
: fields are in fact the same type.

Although I did find a SQL92 document on the web in the amount of time this
took to copy back to me, and I see the clause about NULL <comp op>
<anything> being unknown.  Which, I imagine, means "implementation
dependent".

-- 
-- Todd Vierling (tv@pobox.com)