convert Data Model to Object Model

[kri shan]

Any tool in the market to convert data model to object model(Class diagram)? (Rational / something else). Practically is it possible ?

[Svend Rost]

What your searching for is an object relational mapping(O/RM) tool or framework.

Take a look at:

http://en.wikipedia.org/wiki/Object-relational_mapping

www.hibernate.org/

or goto google and search for object relational mapping or

/Svend Rost

[Ilja Preuss]

Well, an ORM tool will map data to objects at runtime, based on the existing models.

Some of them also include tools to create object models out of data models or the other way around, but the result typically is less than optimal. That's because the forces that drive the data model (efficient queries on the data) are very different from those that drive the object model (behaviour).

I think Scott Ambler has some good articles on the topic online - google for "agile data" for a starting point.

[Svend Rost]

My bad. I assumed he was looking for something to use at runtime. I should
have read his post more thoroughly.

In case you choose to perform the mapping (more or less) by hand, you might
find Fowlers Enterprise Architecture Patterns interesting: http://www.martinfowler.com/eaaCatalog/

/Svend Rost

[Fintan Conway]

Originally posted by kri shan:
Any tool in the market to convert data model to object model(Class diagram)? (Rational / something else). Practically is it possible ?

Hi Kri,

Java Database Objects (JDO) will do this for you. There are many free and commercial JDO products. JPox is a good free JDO product.

Regards,

Fintan

[Peer Reynders]

Originally posted by Ilja Preuss:
...but the result typically is less than optimal. That's because the forces that drive the data model (efficient queries on the data) are very different from those that drive the object model (behaviour).

I think Scott Ambler has some good articles on the topic online - google for "agile data" for a starting point.

FYI: kri shan was referred to the articles back in April Data Model ------> Object Model.

Those articles offer an explanation to why tools of that nature would be rare and of limited usefulness (as you have indicated).

[Scott Ambler]

You might find Why Object Models Shouldn't Drive Data Models (and vice versa) to be of interest. Although it is quite straightforward to generate an object model from a data model, or a data model from an object model, you likely will not get what you actually want from the generation. The tools that do this do an OK job of it, but as I show at Mapping Objects to RDBs you have to make important decisions when you do OR mapping. The end result is that because you have choice, it isn't possible to produce a perfect automation tool.

You can automate the grunt work though.

- Scott