Re: More on lists and sets

From: Jon Heggland <jon.heggland_at_idi.ntnu.no>
Date: Thu, 23 Mar 2006 16:37:43 +0100
Message-ID: <dvufg0$p8v$1_at_orkan.itea.ntnu.no>


David Cressey wrote:
> In this case, I'm interested in storing the data in relational tables
> (because of the power described by Codd Date & Darwen, etc), but I think a
> programmer is legitimately interested in viewing the data as if it were a
> hierarchy. (I'm treating HDM and MVDM as equivalent for purposes of this
> illustration).
>
> So I'm interested in a sublanguage that can SELECT the data using relational
> operators to join data from at least 3 tables, but can DELIVER the data to
> the program in NFNF (see Dawn's blog). That transfom is, as you pointed
> out, trivial from an information perspective.

I honestly can't see what this has to do with database theory and (sub)languages; or with lists versus sets versus bags. It's a user interface issue, isn't it? Why do you need a special language for this?

> But it's not very easy from a programming perspective. And programmers
> would be more productive if it were easy.

It is *very* easy in Dataphor. Just put "embedded" tags on the two foreign key definitions.

-- 
Jon
Received on Thu Mar 23 2006 - 16:37:43 CET

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