RE: associations defined in a metamodel



Date view Thread view Subject view Author view Attachment view

From: Chris Britton (chris.britton@blueyonder.co.uk)
Date: Fri 17 May 2002 - 11:42:54 BST


Simona,

When we tried to implement meta models in practice, almost everything
that looks like a one-to-many relationships ends up as a many-to-many
relationship in the meta model. For instance, if the meta model is for a
relational database it looks like there should be a one-to-many
relationship between meta-table and meta-column. But while you could
model it that way, in practice you often want to have the same column
definition used in multiple tables.

The other factor that comes into play in a practical solution is that
you usually want version control and you might end up with different
version of the meta-table being associated with different versions of
the meta-column. 

Best regards,
Chris

-----Original Message-----
From: puml-list-request@cs.york.ac.uk
[mailto:puml-list-request@cs.york.ac.uk] On Behalf Of Simona Bernardi
Sent: 15 May 2002 16:45
To: puml-list@cs.york.ac.uk; bernardi@di.unito.it
Subject: associations defined in a metamodel

Hello,

I have a question about how associations defined in a UML meta-model are
instantiated.
What happens to the multiplicities of an association  defined between
two meta-classes ?
For example an association  "ass" is defined between two metaclasses A
and B,
with multiplicity * (not explicitly defined):

        ass
|A| -----> |B|
          *

An instantiated model can be made of  a class A' (instance of the
metaclass A)
and a class B' (instance of B) and relation ass' between A' and B'.
Does the multiplicity of ass' have to be a specific number or it can
still remain unspecified with "*" ?

Thanks,
Simona.




To remove yourself from this list please mail
puml-list-request@cs.york.ac.uk
with a message containing the word "unsubscribe".

Date view Thread view Subject view Author view Attachment view