• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: Inverse to-one relationships
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Inverse to-one relationships


  • Subject: Re: Inverse to-one relationships
  • From: Paul Hoadley <email@hidden>
  • Date: Fri, 23 Jul 2010 07:19:33 +0930

On 23/07/2010, at 12:09 AM, Chuck Hill wrote:

I know this topic comes up on the list from time to time, but I just need a quick sanity check.

Nope, not sane.  :-)

Well spotted.  Now on with this:

I have two entities, A and B.  For every A, there is a corresponding B.  For some subset of all Bs, each has a corresponding A.  Currently I have modelled this with a single relationship from A to B, so that's a mandatory to-one relationship.  (Alternatively, I could have modelled it with an optional to-one relationship from B to A.)

How are you modeling these relationships?

Originally, just this: a mandatory, to-one relationship from A to B.  Consider it to be a parent (B) with optional child (A).  Every child has a parent (hence the current mandatory to-one from A to B), and every parent has zero or one child.  So I've tacked on an optional to-one relationship from B to A to model the latter.  I take it there's no way to convince EOF that these relationships are inverses, and get the convenience of updating both sides of the relationship at the same time.


-- 
Paul.

http://logicsquad.net/


 _______________________________________________
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: Inverse to-one relationships
      • From: Chuck Hill <email@hidden>
References: 
 >Inverse to-one relationships (From: Paul Hoadley <email@hidden>)
 >Re: Inverse to-one relationships (From: Chuck Hill <email@hidden>)

  • Prev by Date: Re: Inverse to-one relationships
  • Next by Date: Re: Inverse to-one relationships
  • Previous by thread: Re: Inverse to-one relationships
  • Next by thread: Re: Inverse to-one relationships
  • Index(es):
    • Date
    • Thread