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Groups > comp.databases.ms-sqlserver > #1671

Re: A question about relationship

From "Tony Johansson" <johansson.andersson@telia.com>
Newsgroups comp.databases.ms-sqlserver
Subject Re: A question about relationship
Date 2014-02-11 15:39 +0100
Organization A noiseless patient Spider
Message-ID <lddcn4$i2b$1@dont-email.me> (permalink)
References <ldan3d$f0i$1@dont-email.me> <XnsA2D0F0AEE3E6Yazorman@127.0.0.1>

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Yes a customer without order sounds ok
But order without customer is incorrect.

//Tony

"Erland Sommarskog" <esquel@sommarskog.se> 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 

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Thread

A question about relationship "Tony Johansson" <johansson.andersson@telia.com> - 2014-02-10 15:18 +0100
  Re: A question about relationship Erland Sommarskog <esquel@sommarskog.se> - 2014-02-10 23:39 +0100
    Re: A question about relationship "Tony Johansson" <johansson.andersson@telia.com> - 2014-02-11 15:39 +0100
      Re: A question about relationship Ross Presser <rpresser@gmail.com> - 2014-02-11 07:11 -0800
        Re: A question about relationship bradbury9 <ray.bradbury9@gmail.com> - 2014-02-11 08:43 -0800
          Re: A question about relationship Ross Presser <rpresser@gmail.com> - 2014-02-11 09:33 -0800
        Re: A question about relationship Lennart Jonsson <erik.lennart.jonsson@gmail.com> - 2014-02-11 18:01 +0100
      Re: A question about relationship Erland Sommarskog <esquel@sommarskog.se> - 2014-02-11 21:54 +0100
        Re: A question about relationship rja.carnegie@gmail.com - 2014-02-11 13:49 -0800
          Re: A question about relationship Erland Sommarskog <esquel@sommarskog.se> - 2014-02-11 23:23 +0100

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