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: "Tony Johansson" Newsgroups: comp.databases.ms-sqlserver Subject: Re: A question about relationship Date: Tue, 11 Feb 2014 15:39:17 +0100 Organization: A noiseless patient Spider Lines: 23 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="Windows-1252"; reply-type=original Content-Transfer-Encoding: 7bit Injection-Date: Tue, 11 Feb 2014 14:39:32 +0000 (UTC) Injection-Info: mx05.eternal-september.org; posting-host="8fdc2b5af81c338deb7045fc6c39b0e2"; logging-data="18507"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/L3CrilhfK0bD+UlXeKLR6" X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18463 In-Reply-To: X-Newsreader: Microsoft Windows Mail 6.0.6002.18197 Cancel-Lock: sha1:YFxYEZIw17wQmEjR200k/LX2dTQ= X-Priority: 3 X-MSMail-Priority: Normal Xref: csiph.com comp.databases.ms-sqlserver:1671 Yes a customer without order sounds ok But order without customer is incorrect. //Tony "Erland Sommarskog" skrev i meddelandet news:XnsA2D0F0AEE3E6Yazorman@127.0.0.1... > 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