Re: Parallel structure EO modeling
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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