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Re: Defining child Entities.
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Re: Defining child Entities.


  • Subject: Re: Defining child Entities.
  • From: David Avendasora <email@hidden>
  • Date: Tue, 11 Aug 2009 07:02:53 -0400


On Aug 11, 2009, at 6:21 AM, Gustavo Pizano wrote:

Hello Im doing an eomodel.. .and I have an entity called Area, and SubArea, for me an area can have many subareas, but subarea its an area itself also..
so its like Area <- >>SubArea.

If a SubArea is really just an Area with a parent, then I'd just have one Entity of Area with an optional to-one relationship to parent.


I'd model it as Area <->> Area with Area having a foreign key that points to the PK. You'll end up with each Area having a parentArea and multiple subAreas.

This assumes that an Area can have only one parent. If an Area can have more than one parent, then you'll need a many-to-many join.

Dave



Now what are the implications of defyning Area with its properties, and then SubArea and put as parent Area?... I see that inside Area Entity there is SubArea Entity also... but I guess this doesn't guaranties me the to-many relationship between the 2 entities isn't it?do I still have t defying the relationship?



Thanks

 Gustavo

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 >Defining child Entities. (From: Gustavo Pizano <email@hidden>)

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