Re: Clues on modeling a really simple concept
Date: Wed, 13 May 2009 04:34:08 -0700 (PDT)
Message-ID: <4e354bea-6ac5-4012-9375-eff09579ad8e_at_l28g2000vba.googlegroups.com>
On 6 Apr, 21:01, Spike <fau..._at_gmail.com> wrote:
> Both galleries and pictures belongs to a single user, but a single
> picture can be used on many galleries.
>
> users --> pictures --> pictures_to_galleries --> galleries
>
> My question is: Should i add a relationship between galleries and
> users?
Yes, because the role in which a picture "belongs" to a user and a gallery "belongs" to a user is likely to be entirely different, thus not modelled through this transitive relation.
If pictures are shareable by galleries, but pictures only "belong" to a single user, then I can only assume from this that "belong" here means some sort of creator or IP owner role. That's sensible, but quite different from the "inclusion in a set" role with galleries.
On the whole, I'd suggest ignoring the database model for the moment and focussing on image metadata, probably beginning with a look at Dublin Core. Once you have a clearer metadata model in your mind, you can think about RDBMS schema to represent it. Received on Wed May 13 2009 - 13:34:08 CEST