The starting point for making a JavaScript data model is an association-free information design model like the following one:
 |
Notice the unidirectional many-to-one association between Book and
Publisher, assigning at most one publisher to any book, which is represented by the
reference property publisher in the Book class.
The meaning of the design model can be illustrated by a sample data population for the two
model classes Book and Publisher:
Table 12.1. Sample data for Publisher
| Name | Address |
|---|---|
| Bantam Books | New York, USA |
| Basic Books | New York, USA |
Table 12.2. Sample data for Book
| ISBN | Title | Year | Publisher |
|---|---|---|---|
| 0553345842 | The Mind's I | 1982 | Bantam Books |
| 1463794762 | The Critique of Pure Reason | 2011 | |
| 1928565379 | The Critique of Practical Reason | 2009 | |
| 0465030793 | I Am A Strange Loop | 2000 | Basic Books |
We obtain the JPA entity class Publisher from the corresponding information
design class, as explained in the previous parts of this tutorial, by (1) replacing the
stereotype «stdid» with the property modifier {id}, (2) making all properties private, (3) using
Java datatypes, (4) adding public getters and setters, (5) adding a toString
function, (6) adding the data storage methods add, retrieve,
update and destroy, as well as the helper methods
clearData and createTestData:
In the JPA entity class model, for any association end dot in the design model, we show the
reference property representing the association end and annotate it with the functionality type
of the unidirectional association represented by it. In our example, we add a reference property
publisher in the entity class Book and annotate it with the
association's functionality type manyToOne:
