
> -- If I have interpreted SQL92 correctly UNKNOWN IS TRUE should return
> FALSE, and UNKNOWN IS NOT TRUE is equivalent to NOT (UNKNOWN IS TRUE) ==>
> TRUE. Is this correct?

No, I do not think it is valid to say "should return true|false"
I think they should return UNKNOWN. Only when it comes to evaluating the
"... WHERE UNKNOWN;" can you translate it to "... WHERE FALSE;", or in the 
output function.

My interpretation would be:
UNKNOWN IS TRUE 		--> FALSE
UNKNOWN IS NOT TRUE 	--> FALSE
NOT (UNKNOWN IS TRUE)	--> FALSE

Andreas

Tue, 19 Jun 2001 09:10:25 +0200
Zeugswetter Andreas SB  <ZeugswetterA@wien.spardat.at>
AW: AW: Re: [SQL] behavior of ' = NULL' vs. MySQL vs. S
	tand ards