Re: Object-Role Modeling?

From: Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be>
Date: Tue, 12 Jul 2005 20:39:35 GMT
Message-ID: <bUVAe.143373$R_.7600172@phobos.telenet-ops.be>

Alfredo Novoa wrote:
> On Sun, 10 Jul 2005 10:47:04 GMT, Jan Hidders
> <jan.hidders_at_REMOVETHIS.pandora.be> wrote:
>
>

>>Many people seem to like to begin with ER diagrams. I happen to think 
>>that there's a reason for why they caught on as they did. And if you 
>>supply them with a formal semantics and a constraint and query language 
>>(which is easy to do and has in fact already been done by several 
>>researchers) then it qualifies as a database schema.

>
> Then you would reinvent ORM and almost nobody would use that :)

Actually it would be an extension of ORM. ORM lacks a few of those things.

> And you would have to complement the diagrams with textual business
> rules anyway, like with ORM.

Yeah, sure.

>>Only implementation details like choosing primary keys or choosing 
>>whether or not to embed a one-to-many relatinship have to be skipped. 
>>All logically relevant details will still be in there.

>
> What about something like: the current stock *IS* the initial stock
> plus the purchases and the customer's returns minus the sales, the
> consumption, the loses and the returns to the providers.

That would be expressible.

Jan Hidders

Received on Tue Jul 12 2005 - 15:39:35 CDT