Programming languages, perhaps, but clearly not uncommon in SQL ... Informix certainly allows a column to be of type boolean but with a value of NULL for given rows (unless precluded by a not-null constraint). Should we question integers, which can be positive, negative, or -- gasp ! -- NULL ?
I don't see what your point is. That SQL is wrong ? Or that SQL is not "C" ? Or that SQL is not a "programming language" ? "?Que purposa sirve tanto comedia ? Quien inventan tab miseria ?" Greg Williamson DBA GLobeXplorer LLC -----Original Message----- From: sad [mailto:[EMAIL PROTECTED] Sent: Wed 6/23/2004 10:01 PM To: [EMAIL PROTECTED] Cc: Subject: Re: [SQL] feature request ? On Wednesday 23 June 2004 21:12, you wrote: > Sad, > > > since BOOL expression has three possible values: TRUE,FALSE,NULL > > plpgsql IF control structure should have three alternate blocks: > > THEN,ELSE,NULL > > > > shouldn't it ? > > No, why? > > How would you construct a tri-valued IF/THEN? Doesn't seem too likely > to me, as well as being different from every other programming language in > existance ... Three valued BOOLEAN is already different "from every other programming language in existance" ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
