Building a class model from RDMS Model

[beachdefender]

Hi,
Most of the projects I have been involved in lately tend to start with an existing application with a rdbms database and a legacy platform or front end.  

I have found that using EA to extract the existing data structures and refining that in to a new model has been a very successful mechanism in helping organisations evolve their internal systems or (in the current case) software products.

I've used EA for some time to devleop use case models, etc.  But as yet I have not seen a simple mechanism to automate the development of the first layer of a new database abstraction layer from the RDBMS model.

Is there a mechanism to do this or do I need to build the class structures from scratch?

[Geert Bellekens]

You can import the tables in your EA model, but there's no way to create a logical data model from the physical data model.

The reason is that it is plain impossible.
When transforming from logical to physical (relational) database model you make choices.
You decide from which point in an inheritance table you make a table. (all subclasses in one table, or one table for each subclass, or something in between)
You also decide what do to with n-m relations, whether or not to add the field of a datatype inline as columns, etc...

All this information is simply not present in your database model, so there's no way to reverse engineer that logical to physical transformation.

Geert

[Dermot]

There are some Transform scripts available on the Community site for doing a reverse transform from DDL (Physical) to Logical and Logical to Conceptual - see: http://community.sparxsystems.com/community-resources/512-84data-modeling-logical-and-conceptual-mda-transforms

[beachdefender]

Hi,
Thanks,  I'll take a look.

Stay well
Barry