Re: Database design, Keys and some other things

"JOG" <jog_at_cs.nott.ac.uk> wrote in message news:1128041327.569631.11250_at_g49g2000cwa.googlegroups.com...

> The difference is analagous to the following - below is the graph
> component for some arbitrary mapping:

> f = { <a,1>, <b,2>, <c,3> }

> In the math, f is the symbol by which I will reference this graph, and
> would use to refer to the mapping inside further relations. I won't
> reference it by one of its tuples, and the f symbol certainly belongs
> outside of the set it represents, not encoded as a tuple within it. The
> distinction is between container and the content.

In the RM there are no entities. There are only values and relations. Also it is based on the first order logic. Anything else need to be solved outside the model.

If you have a problem with this, and some ideeas to solve it, you are wellcome to share them. Received on Fri Sep 30 2005 - 10:17:49 CEST