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Re: Nead a guru in to-many relations
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Re: Nead a guru in to-many relations


  • Subject: Re: Nead a guru in to-many relations
  • From: Ricardo Strausz <email@hidden>
  • Date: Wed, 30 Jul 2003 18:16:46 -0500

On miircoles, juli 30, 2003, at 17:01 America/Mexico_City, Art Isbell wrote:

On Wednesday, July 30, 2003, at 10:39  AM, Ricardo Strausz wrote:

How can I neast objects of the same kind over and over??
Is there a usefull db/sql/eof mechanism to perform this??

A relationship whose source and destination entities are the same is called a reflexive relationship. You'll need to add a foreign key to the entity so you can equate the primary key of the source object with the foreign key of the destination objects as with any to-many relationship. EOModeler supports this. You should be able to treat this as with any to-many relationship. With this configuration, the number of levels of relationships is not limited.


I suppose a difficulty with this configuration is how to display the reflexive relationship objects since the number of levels is unlimited. It may not be easy to automatically prefetch all related objects because the number of levels can't be known initially.

Are there specific questions you have about such a configuration?

I simply didn't this was possible... I do not know way, but I allways thought of a relation between two (different) tables, but I will try with reflexive ones. It sounds like this will do the trick.


Do you have any advise about deletation rules? are they as usal??
I ask this becouse I can imagine (not in my case, but possibly) a loop of relations and then ownership and deletation rules seems like a possible problem source which I do not know if it is prevented by EOF.


Gracias Art!


Aloha,
Art
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Dino http://homepage.mac.com/strausz _______________________________________________ webobjects-dev mailing list | email@hidden Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/webobjects-dev Do not post admin requests to the list. They will be ignored.

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