Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!drn.maxwell.syr.edu!news.maxwell.syr.edu!border1.nntp.dca.giganews.com!nntp.giganews.com!local1.nntp.dca.giganews.com!news.giganews.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 06 Jun 2005 17:10:03 -0500 Message-Id: From: Kenneth Downs Subject: Re: Does Codd's view of a relational database differ from that ofDate& Darwin? [M.Gittens] Newsgroups: comp.databases.theory Date: Mon, 06 Jun 2005 17:51:09 -0400 References: <1117636456.185385.128930@g44g2000cwa.googlegroups.com> <3R6oe.1962$F7.1337@news-server.bigpond.net.au> <42a40b89$1@news.fhg.de> <42a4246c$0$41930$ed2619ec@ptn-nntp-reader03.plus.net> <42a42c05$1@news.fhg.de> <42a471ea$0$41904$ed2619ec@ptn-nntp-reader03.plus.net> Organization: Secure Data Software, Inc. User-Agent: KNode/0.8.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit Lines: 31 X-Trace: sv3-ZcZ0ATMtUpYgT63fkIQpDMIKGXk9fRUrn7r6PT6PAIrUS2Be1F8aNTWmllQs02mxZo+I1O51XmW98BA!QXFhRIeEQ0VWjvuhHbzqyr7AgkDgkjM85rX2WDuUydPDQ8703i9/4R5Ahrs= X-Complaints-To: abuse@giganews.com X-DMCA-Notifications: http://www.giganews.com/info/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.32 Xref: dp-news.maxwell.syr.edu comp.databases.theory:31273 paul c wrote: > Paul wrote: >> paul c wrote: >> >>>i'd like to know what problem the never-ending arguments about nulls are >>>aimed at. in mundane applications at least (which i think is where most >>>people spend their time), what is the problem with using empty strings >>>for unknown names or zeroes for unknown number values? >> >> >> Because the empty string or zeros might also be valid values. >> ... > > perhaps i confused things a little by mentioning empty strings instead > of blanks. personally, i find it hard to care whether i know that i > don't know a person's name or whether i simply call him him Mr. 'blank'. > maybe i know the wrong people but most people i know are content > with items on an invoice having a price of zero dollars (maybe i shipped > an item an item before i knew its price) assuming this is anticipated by > the application or preferably the db with partial invoices or somesuch > notion. i think this is easier to explain to people than 3-valued logic. > > Suitable for framing! -- Kenneth Downs Secure Data Software, Inc. (Ken)nneth@(Sec)ure(Dat)a(.com)