In database modeling, you use a UML diagram to design a logical database schema. This diagram shows the database tables and the mutual relationships between these tables.
Microsoft Visio for Enterprise Architects provides the following templates that allow you to design and document logical database schemas for relational and object-relational databases:
Database model diagram: Creates logical database model diagrams.
Object Role Mode (ORM) diagram: Models an enterprise system in terms of objects and the roles they play in that enterprise system.
Express-G: Creates entity- and schema-level diagrams that use Express-G notation.
ORM source model: Maps the ORM model to a logical database model. This allows you to create a physical database schema.
Entity Relationship (ER) source model: Develops and maintains different sub models of a system in the form of entities involved in that system and the relationship between the entities. This allows you to map the mutual interactions between the sub models.
The database model diagram template allows you to design and document logical database model diagrams for relational and object-relational databases. You can create a database model diagram from scratch or:
Reverse engineer an existing database into a database model diagram.
Import an existing database model diagram created in another program.
If the logical database model that graphically shows the relationships between the database tables is well-defined , you can ensure that any information system you design will be accurate, complete, and efficient.
Figure 1-1 shows a sample database model diagram for an Airlines database: