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Re: Are one-to-one relationships valid?
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Re: Are one-to-one relationships valid?


  • Subject: Re: Are one-to-one relationships valid?
  • From: Guido Neitzer <email@hidden>
  • Date: Sun, 6 Apr 2008 14:03:45 -0600

On 06.04.2008, at 12:53, Daniel DeCovnick wrote:

I've got a situation where I'm about 99% sure I should use a one-to- one relationship. I've got about 100 attributes that can be logically divided into 14 different categories. A single entity (Note) would then have one of each of these categories (if modeled as separate entities). There's no reuse possible of instances of the categories.

Problem: The Create Relationship dialog in Entity Modeler won't let me create a one-to-one relationship.

Question: Does this mean you can't have one-to-one relationships? And if you can, how do you set one up?

In WebObjects a "normal" 1:1 relationship is modeled with joining on the primary keys and have the "master" entity propagate its pk to the "slave". As soon as you create a master entity you'll get the other end created automatically, so do not create another one!


If you don't want that, you need to model it yourself, e.g. with a 1:n and cover methods to make the to n part a to 1 part.

cug

--
http://www.event-s.net

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References: 
 >Are one-to-one relationships valid? (From: Daniel DeCovnick <email@hidden>)

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