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Re: Horizontal inheritance between different models and different databases.
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Re: Horizontal inheritance between different models and different databases.


  • Subject: Re: Horizontal inheritance between different models and different databases.
  • From: David Avendasora <email@hidden>
  • Date: Wed, 20 Nov 2013 08:30:54 -0500

Hi,

On Nov 20, 2013, at 4:38 AM, Comm unity <email@hidden> wrote:

An empty fault could not be created because the object's class could not be determined (e.g. the GID is temporary or it is for an abstract entity).

Note that last bit.

Is it possible that when you were trying to use inheritance that you flagged the ParentEntity (in EntityModeler) as being Abstract?

If you did, then that is why you can’t instantiate it. Just uncheck it.

HOWEVER…

The EOModel is the foundation of any WO application. Choices you make in defining the Entities and their relationships will make profound differences in how every other aspect of how your application works. Get it right and it will seem like the app writes itself. Get it wrong and you’ll be constantly writing extra code to deal with the dissonance created by the model not truly representing reality. 

Let me ask this: Is this an existing set of databases, or ones that you are creating specifically for your application?

If the databases are just for your application, I think you should reconsider how you are architecting things.

If it is an existing set of databases, is there anything you can do at the DB level to simplify the structure? Some database engines have ways to hide things like cross-database inheritance.

Dave


—————————————————————————————
WebObjects - so easy that even Dave Avendasora can do it!™
—————————————————————————————
David Avendasora
Senior Software Abuser
Nekesto, Inc.





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References: 
 >Re: Horizontal inheritance between different models and different databases. (From: Chuck Hill <email@hidden>)
 >Re: Horizontal inheritance between different models and different databases. (From: David Avendasora <email@hidden>)
 >Re: Horizontal inheritance between different models and different databases. (From: Comm unity <email@hidden>)

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