UML class diagrams

Unified Modeling Language (UML) is a standard developed by the Object Management Group (OMG). UML diagrams are widely used in modeling software solutions, and there are several types of UML diagrams for different modeling purposes including class, use case, activity, and implementation diagrams.

A class diagram can represent several types of associations, that is, the relationship between classes. They can depict attributes as well as methods. An ER diagram can be easily translated into a UML class diagram. UML class diagrams also have the following advantages:

• Code reverse-engineering: The database schema can be easily reversed to generate a UML class diagram.
• Modeling extended relational database objects: Modern relational databases have several object types such as sequences, views, indexes, functions, and stored procedures. UML class diagrams have the capability to represent these object types.

The following class diagram is generated from reverse-engineering the SQL code of a car_portal database: