Re: Object-oriented thinking in SQL context?

From: Marshall <marshall.spight_at_gmail.com>
Date: Wed, 17 Jun 2009 08:55:30 -0700 (PDT)
Message-ID: <b54e1d0c-fcae-42c5-90de-587deb186595_at_w3g2000yqf.googlegroups.com>


On Jun 17, 4:45 am, "Nilone" <nil..._at_mega.co.za> wrote:
> "Bob Badour" <bbad..._at_pei.sympatico.ca> wrote in message
>
> >> Think 'class' ~ 'relation' (table)
>
> > But that would not only be a blunder but a great blunder.
>
> I'd like to clarify this for anyone coming from the OO side.  If you map
> class to relation, you're breaking the OO rule of encapsulation and reducing
> the class to a simple aggregate type (struct).  Presumably, you chose an
> encapsulated, polymorphic abstraction device for a reason, or did you do so
> just because you (or somebody at your company) read Lhotka's book?  Classes
> map to domains (types) in the relation model, but be aware that subclassing
> is NOT subtyping.

Speaking just for myself, when I am programming in an OO language, I map classes to whatever I feel like. OO really only provides the one unit of abstraction, the class. If the only tool you have is a class, everything looks like an object. Or something.

In other words, when I want an abstraction for something in Java, I make it a class, because that's about the only choice.

Marshall Received on Wed Jun 17 2009 - 17:55:30 CEST

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