Re: Does Codd's view of a relational database differ from that of Date&Darwin? [M.Gittens]
Date: Fri, 10 Jun 2005 09:42:28 +0200
In article <AC5qe.11727$F7.5746_at_news-server.bigpond.net.au>,
> >> And x + NULL does not evaluate to NULL but x.
> > I should have mentioned that I am talking about the SQL2 standard (or
> > SQL/92 or SQL:1992 or SQL-92 or whatever it is called). I am not
> > familiar with MS TSQL.
> It appears to be an ISO/ANSI SQL standard. SQL-99:
What does NULL + NULL evaluate to? NULL or 0?
How about NULL - NULL? And NULL = NULL? Is x = y and x - y = 0
equivalent (x and y being integer range variables)?
How about NULL - NULL? And NULL = NULL? Is x = y and x - y = 0 equivalent (x and y being integer range variables)?
-- JonReceived on Fri Jun 10 2005 - 09:42:28 CEST