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Re: Parallel structure EO modeling
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Re: Parallel structure EO modeling


  • Subject: Re: Parallel structure EO modeling
  • From: Ken Anderson <email@hidden>
  • Date: Tue, 26 Feb 2013 16:45:49 -0500

Ramsey,

Well, this really isn't a business rule - it's basically just that data will be separated by Male/Female, and you would never attach a Male version of something (like a workout) to a female customer.  I like it when the model enforces data validity in that way, but I think it's just too much trouble to have triple the number of entities (M/F/abstract) to make it work.

Thanks,
Ken

On Feb 26, 2013, at 3:38 PM, Ramsey Gurley <email@hidden> wrote:

> Can you give a concrete example illustrating what you mean? Generally I stay away from enforcing business rules with the schema. When business rules change, as they always do, you're boned. I use the schema to enforce data integrity.
>
> Ramsey
>
> On Feb 26, 2013, at 1:11 PM, Ken Anderson wrote:
>
>> All,
>>
>> I have a difficult decision to make and am waffling back and forth.  I'm hoping some of you guys might have come across a similar situation and would have some recommendations.
>>
>> I have a model where a number of entities can by applied only to males or only to females (it's an exercise app).  Part of me wants to create sub-entities called "Male…" and "Female…" because EOF will effectively validate relationships for me.  Unfortunately, it's a pretty deep entity hierarchy and there would be a lot of entities that would have to fall into this category.  Not to mention there are join tables that wouldn't have an M/F flag, but to stay consistent would have to be subclassed as well.
>>
>> Any thoughts?  I would do them all with single table inheritance, so there wouldn't be much of a performance hit.
>>
>> Thanks,
>> Ken
>>
>>
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  • Follow-Ups:
    • Re: Parallel structure EO modeling
      • From: Philippe Rabier <email@hidden>
References: 
 >Parallel structure EO modeling (From: Ken Anderson <email@hidden>)
 >Re: Parallel structure EO modeling (From: Ramsey Gurley <email@hidden>)

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