Re: Mixing OO and DB

From: Bob Badour <>
Date: Fri, 08 Feb 2008 09:57:09 -0400
Message-ID: <47ac5fb6$0$4077$>

David Cressey wrote:

> "Victor Porton" <> wrote in message

>>I know both object oriented programming and DB (SQL). But it seems
>>that these are incompatible. Or may somebody advice how to meddle them
>>Being strong in both OOP and DB development, I am yet weak in writing
>>object oriented programs which use DB.
>>Maybe somebody may suggest me some article about mixing together DB
>>and OOP?

> First off, I think it's reall the mixing of OO and RDM that's of interest,
> rather than the mixing of OO and DB.
> Better minds than mine have attempted to deal with the impedance mismatch
> between OO and RDM. In general, they have been disappointed by their own
> results.

Nuh uh--Not me! I was not disappointed. Raising the programming language from the low OO level to the higher RM level works great!

> I suspect that most of them have gone about it in the wrong way. Most of
> them have tried to project an object world onto a system of relations. What
> they end up with is presistent data that captures the state of each object,
> and its membership in a class. The behavior of objects that belong to any
> class is generally defined outside of any coherent data model (even if it's
> stored in a blob in a database).
> I think it might be interesting to explore the whole concept backwards:
> start with the idea that a table is just a specific class of object,

A great blunder.

and a
> persistent table is just a specific class of persistent object. Then come
> up with two things: how to store persistent objects and retrieve them when
> necessary without regard for any data model; and how to get tables and
> application objects to collaborate on common objectives.
> This doesn't sound easy to me, at all. But it could be promising, provided
> there is real value in OO. I don't know OO well enough to have a considered
> opinion on that score.

Have you read _The Third Manifesto_ ? D&D put a lot of thought into what parts of OO have any real value. Received on Fri Feb 08 2008 - 14:57:09 CET

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