Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Erland Sommarskog Newsgroups: comp.databases.ms-sqlserver Subject: Re: A question about relationship Date: Mon, 10 Feb 2014 23:39:36 +0100 Organization: Erland Sommarskog Lines: 15 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Injection-Info: mx05.eternal-september.org; posting-host="fd3d6d0229f14a752f017d8f9903addd"; logging-data="17654"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/KiAZ7ZnoQ6jnltQVV5ynl" User-Agent: Xnews/2006.08.24 Mime-proxy/2.1.c.0 (Win32) Cancel-Lock: sha1:FgF1GT/0VcQizmsw8BLrgBQzX6w= Xref: csiph.com comp.databases.ms-sqlserver:1669 Tony Johansson (johansson.andersson@telia.com) writes: > What I find strange is the relationship between Customer and Order. > The book print the relationship between Customer and Order like this > !--------------! !-------------------! > ! Customer ! 0.1 ................ * ! Order ! > !--------------! !-------------------! > I found this strange because it means you can have orders without a > Customer. Not sure how to interpret that, but there can certainly be customers without orders. I believe that Northwind has three of them. -- Erland Sommarskog, Stockholm, esquel@sommarskog.se