Re: Bussines objects

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From: Joanna Carter \(TeamB\) (joannac_at_nospamforme.com)
Date: 02/25/05 

Date: Fri, 25 Feb 2005 14:15:49 -0000

"MyGeneration" <MyGeneration@discussions.microsoft.com> a écrit dans le
message de news: D8CFB01B-6DDE-4407-8331-E41F286B80D7@microsoft.com...
> I wholeheartedly disagree wtih this statement.

You are entitled to your opinion but...

> Your application in the end exists only to manipulate data, the data is
the
> application, everything line of code your write exits to flip a bit or
save a
> value in your database. Starting with the database and working from the
> ground up is an excellent and proven way to write an application, and is
how
> most do it.

Database design used to be the standard, well-proven basis for non-OO
applpications; I know, I was weaned on Logical Data Structure diagrams.

But where do you put the code that manipulates the data ?

Please don't tell me you use data-aware controls directly connected to
database tables and write the code in event handletrs on the forms!! :-))

Not all data in an application is stored in a database. In a well designed
OO application you may well have hundreds of classes that have nothing to do
with *stored* data.

The frameworks I have written to support my applications contain around 300
classes and interfaces.

There is the Value Type Framework that gives me more metadata about my
business objects and their properties.

There is the Object Persistence Framework that allows me to write OO code
that knows nothing about databases because the OPF translates business
objects to/from database tables, generating SQL on the fly. I only ever use
one Query component, one Transaction component and on database component in
my entire application and frameworks combined.

There is the MVP framework that allows me to replace my UIs without having
to change any of the code in either my business objects or the applications
that use them.

etc...

How would I extract those classes and interfaces from a database ?

What about those applications that don't use databases ?

> Once you have your database design you can then use that very useful AND
> accurate data to generate the classes that represent that data.
MyGeneration
> does exactly that.

How does your software translate the Sales Order example I gave ? 

--
Joanna Carter (TeamB)
Consultant Software Engineer
TeamBUG support for UK-BUG
TeamMM support for ModelMaker

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