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Re: Inverse to-one relationships
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Re: Inverse to-one relationships


  • Subject: Re: Inverse to-one relationships
  • From: Chuck Hill <email@hidden>
  • Date: Thu, 22 Jul 2010 15:02:54 -0700

On Jul 22, 2010, at 2:56 PM, Paul Hoadley wrote:

> Sorry, I should have tried to be clearer.  Basically, I've got a parent object B (which will always be created first).  At some point, B may obtain at most one child A, but it doesn't necessarily.  So every B has zero or one child As.  Every A has exactly one parent B.
>
> Currently I have a mandatory to-one relationship from A to B (so A knows its parent directly).  To avoid some fetching, I have added an optional to-one relationship from B to A, so B knows its child if it has one.  I assume there's no way to make these relationships inverses from EOF's perspective, and that I will just need to be careful about always setting the B to A relationship on creation of an A.


How did you model this?  B hold's the PK of A as a FK?  They each need a FK for the other, I think.  Your relationships should be

B.FKA == A.PK
A.FKB == B.PK


I think...



--
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







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  • Follow-Ups:
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      • From: Paul Hoadley <email@hidden>
References: 
 >Inverse to-one relationships (From: Paul Hoadley <email@hidden>)
 >Re: Inverse to-one relationships (From: David Avendasora <email@hidden>)
 >Re: Inverse to-one relationships (From: Paul Hoadley <email@hidden>)

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