Re: Object-oriented thinking in SQL context?

From: Bernard Peek <>
Date: Tue, 9 Jun 2009 16:20:40 +0100
Message-ID: <>

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<>, writes

>How do OO class concepts map to SQL table concepts?

The answer to that is "badly."

In this newsgroup we occasionally have visitors who claim to have discovered some way to link the two sets of concepts and so far all of the ones we have seen have shown a limited grasp of relational theory. I was one of those but I've hung around long enough to pick up more of the theory. You have been caught in the backwash from dealing with some real idiots. Sorry about that.

We aren't going to be able to give you a crib-sheet that maps the concepts in the two paradigms. Lots of very bright people have been trying to do that for a long while and they haven't succeeded. The assembled multitude here know vastly more about relational algebra than I ever will, I'm a very pragmatic software development manager who happens to concentrate on building infrastructure while managing development teams. I'm going in the opposite direction to you because I'm satisfied that I have enough knowledge of relational databases to be able to design a back-end system I need to make them available to OO developers and analysts.

I've been reading a book called "Beginning C# Databases" from Wrox. It has some information about the .NET architecture and how it wraps relational databases. From reading that I would guess that your most productive route would be to develop your software in one of the OO .NET languages, quite possibly C#.

If you still want to learn about relational theory then this is a very good place to do that, but it won't happen overnight. It's not a trivial task and the advice others have given you, to read some books on the subject, is good (although the advice could have been phrased more tactfully.) Personally I would be much happier if this newsgroup had someone who could fly the flag for OO systems, preferably while being able to walk *and* chewing gum.

There needs to be a better understanding of the mapping between objects and relational systems. For better or worse UML is the de facto standard for the design of new systems.

Bernard Peek
Received on Tue Jun 09 2009 - 17:20:40 CEST

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