Working with ER diagrams

Use ER diagrams to specify relationships among columns of related tables and store these relations.

For example, a table stores the staff data for everyone in a company. This table includes a column that is named DEPT that stores the identifier of the department in which an employee works. Another table stores the organization data of each department in the company. This table includes a column that is named DEPTNAME that stores the name of each department in the company. These two tables are related, as they have columns that can be easily joined. But when a user opens either one of these tables, this relationship is not readily apparent. By creating an ER diagram that includes these two tables and all of their possible joins, you can make this relationship much easier to see. Now when users open these tables, the ER Diagrams editor displays all of the relationships that you saved, and users can make more effective and dynamic reports.