Summary

The most important points you should learn from this chapter are to keep your data modeling abstract and (as much as possible) application-independent. Obviously, you can't anticipate every possible future requirement for the data your application will manage, but try to be forward-thinking when building this abstract model. Incorporate features in your data model to support application features that aren't implemented yet. Remember that it's easier to change your application code than it is to change your data model—that's why you do the data model first.

Now that we've got a workable abstract model of our data, we're ready to begin the rest of our infrastructure design. Following the traditional relational development model, we would now start coding SQL table CREATE statements. In the object-oriented universe, we would flesh out our entities as objects and determine what methods we want to build into each one.

In our case, because we're building an XML application, we'll move first to designing our XML documents.