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Re: uniqueness constraint on an a foreign key
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Re: uniqueness constraint on an a foreign key


  • Subject: Re: uniqueness constraint on an a foreign key
  • From: Chuck Hill <email@hidden>
  • Date: Fri, 19 Sep 2008 11:56:27 -0700


On Sep 19, 2008, at 11:52 AM, Florijan Stamenkovic wrote:


On Sep 19, 2008, at 13:26, Chuck Hill wrote:

If the relationship is mandatory, I'd use the PK.

As in propagate PK? That does not work in this case because there can be A rows that do not have any related B rows.


Or did you mean something else?

Yes, that is what I was thinking of. If it is not really a to-many, why not put the PK of B into A as a FK?


Chuck




On Sep 19, 2008, at 10:00 AM, Florijan Stamenkovic wrote:

Hi all,

I have a relationship A <->> B. B carries the FK for A, not allowed to be null.

I'd like to enforce that a single A can relate to only one B so I'm thinking of putting a uniqueness constraint on the FK. As far as I can see that will give me what I want without causing any trouble. Can anyone think of a reason against doing this, or is there a better practice to address this?

Thanks,
F
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-- Chuck Hill Senior Consultant / VP Development

Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems.
http://www.global-village.net/products/practical_webobjects







_______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (email@hidden) Help/Unsubscribe/Update your Subscription: This email sent to email@hidden
  • Follow-Ups:
    • Re: uniqueness constraint on an a foreign key
      • From: Florijan Stamenkovic <email@hidden>
References: 
 >uniqueness constraint on an a foreign key (From: Florijan Stamenkovic <email@hidden>)
 >Re: uniqueness constraint on an a foreign key (From: Chuck Hill <email@hidden>)
 >Re: uniqueness constraint on an a foreign key (From: Florijan Stamenkovic <email@hidden>)

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