Hallo everybody,

For my diploma I need to deal with the following questions:
I will model my software in ER and UML. ER I will use to model the
database design and UML to model the software itself.
But I would like to know why at all to model in two different
techniques. Is it not possible to model Databases as well in UML? For
sure it is possible, but why on practice ER is still used for this?
What is better with ER? What is better with relation databases?

The other question, I need to find some rules how to translate class
diagram in UML to ER or ER to UML class diagram.

I thought that somebody has made it maybe one and could help me with
useful links or books to this theme or just to tell his opinion about
it.
I would very, very much appreciate your help.

Thank you
Katerina

"Katerina" <ekaterina_zinke (AT) web (DOT) de> schrieb im Newsbeitrag
news:b101300b.0307210110.3ac243c4 (AT) posting (DOT) google.com...
ER diagramming is focused on ER modeling and is thus likely to be better
adapted to that environment.

ER table -> UML class
ER column -> UML (public) attribute

The other direction is more difficult and depends on the circumstances.
Left as an exercise, which all this is about as it seems.

robert

ekaterina_zinke (AT) web (DOT) de (Katerina) wrote in message news:<b101300b.0307210110.3ac243c4 (AT) posting (DOT) google.com>...
that contains the classes of your application will be highly application-
specific. A relational database that describes (a relevant portion of)
reality can be used by many more applications.
- individual parts or aspects of your class - would be accessible
bypassing the methods that your application provides. For a relational
database, each class should be indivisible.
http://www.cetus-links.org/oo_uml.html

"Katerina" <ekaterina_zinke (AT) web (DOT) de> wrote

While I doubt it will make much difference to your diploma, it will
certainly help your education to google for EWD696 and read what Dijkstra
wrote in anger. I suggest you follow that up by reading EWD1036.

Yes, it is possible with object databases. You don't need ER diagram.
There should be several ODBMSs that you can model in UML.
If I recall correctly, Matisse defines database model using UML.

John

Hello Bob, what does it exactly mean "google for EWD696" and where to
find "EWD1036"??
Sorry, I am new here.


"Bob Badour" <bbadour (AT) golden (DOT) net> wrote

Hallo,
thank you for the links. I will check them

peterbroers (AT) floron (DOT) leidenuniv.nl (Theo Peterbroers) wrote in message news:<39bb2c10.0307210710.4eed004b (AT) posting (DOT) google.com>...

Katerina,

Not to speak for Bob, but he almost certainly means you should go to www.google.com (one of the best search
engines on the web) and enter "EWD1036" in the search box, then press the "Google Search" button. I just
tried it and it works for me.

-- Chad (or today, I guess: Chad the butt-in-ski)

Katerina wrote:

ekaterina_zinke (AT) web (DOT) de (Katerina) wrote in message news:<b101300b.0307210110.3ac243c4 (AT) posting (DOT) google.com>...

You just answered your question!

For the same reason that on practice wheels in cars
are round: it works, it is very efficient, cheap and easy
to do. No need to re-invent a new device: wheels work.

Nothing. It simply works.

This is about as open to discussion as can get.
Suffice to say: "better" than what?

Cheers
Nuno Souto
wizofoz2k (AT) yahoo (DOT) com.au.nospam

johnssk (AT) fishhoo (DOT) com (John Sasak) wrote in message news:<1b77ba63.0307231645.5f0e22be (AT) posting (DOT) google.com>...
has been tasked with investigating two different models.

Too many people only know one model, and use that model all the time
even when it is totally inappropriate. The more models you know, the
better you can critique how they apply to the problem in hand, and the
greater confidence you can have that you are using the correct model.

If you only know one model, how are you going to know that it is
appropriate to your problem? At least with two, you can see "here are
the good and bad points of A, here are the good and bad points of B".
More importantly, you are in a position to say "A has too many bad
points, and so does B. Surely there must be a C that's better" :-)

Cheers,
Wol