Drawing Mode
In RISE the information system modeling takes place in drawings.
Using multiple drawings, implementing different sub systems, will make your models clearer and easier to follow. Each drawing can be presented in three different modes, ERD, UML and RDB. A drawing will by default use the drawing mode suggested by the model
presentation convention.
You can switch between the different modes at any time, and you can model your information in any of the modes. To change the drawing mode for the current drawing, the easiest ways are to either right click on the drawing and select drawing mode from the context menu or hit the F9-button for ERD, the F10-button for UML or the F11-button for RDB.
ERD (Entity Relationship Diagram)
RISE supports Entity Relationship Diagrams using the Information Engineering notation (crow’s foot). This notation is suitable for printout of real world models, i.e. large models, because of its space conservative handling of relationships. ERD is an efficient and unambiguous way to represent an information model and it doesn't introduce any constructs or abstractions that aren't native in the world of information modeling.
Image 1: An ERD representation of a model.
UML (Unified Modeling Language)
RISE supports UML Class Diagrams. Using UML over ERD is primerely a matter of choice since UML is similar to ERD. However, UML provides further graphical symbols that you may use to provide hints on the intended implemenation and use of the information model. Note though, that although this may come in handy it actually means you're overspecifying the model.
Image 2: A UML representation of a model, including implementation hints.
RDB (Relational Database)
The Relational Database Diagrams display how RISE interprets the model in terms of a relational database target environment. The diagram displays primary keys, forreign keys etc. The diagram also displays the impact of the
database naming conventions on the model, i.e. it displays how tables, columns, views etc. are named in a corresponding database. The Relational Database Diagram also displays how cross-joins and symmetric relations are implemented using relational tables, see
ER for database developers for more information.
The default name convention, see image below, assures that database objects of different types exist in different namespaces, i.e. that there can be no cross-type name collisions, for instance between tables and views. It also makes sure that you can generate multiple RISE models in to the same logical database. You can of course alter the database naming convention of your model to suit your needs.
Image 3: An RDB diagram representing the result in terms of a relational database.
Using Drawing Mode
Using a combination of the drawing modes is a powerful way of revealing the full picture of your information system. The images above all represent the one and same model in the three drawing modes, ERD, UML and RDB. When describing the model above, you can see the different modes as representing:
- ERD: The raw information model
We have a many to many relation between Project and Person referenced via a Member entity containing member specific attributes.
- UML: The intended implementation of the model
A Project has a list of Members and each Member has a reference to a Person.
- RDB: The result of our model in terms of a relational database
Displaying table names, column names, primary keys, foreign keys etc. as the will appear in a target database.
