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$R_.7600172_at_phobos.telenet-ops.be>
>
> Then you would reinvent ORM and almost nobody would use that :)
>
> What about something like: the current stock *IS* the initial stock
> plus the purchases and the customer's returns minus the sales, the
> consumption, the loses and the returns to the providers.
Date: Tue, 12 Jul 2005 20:39:35 GMT
Message-ID: <bUVAe.143373$R_.7600172_at_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