The purpose of this example is to show how to create an Entity Relationship Diagrams $($ERDs$)$ based on a given scenario. We will follow this example throughout the quarter. An ERD diagram illustrates the logical structure of databases. They are used to sketch out the design of a database. They play a key part in designing an efficient database.

Instructions

The ABC Company has several departments, divisions, and employees. A division operates many departments, but each department is operated by only one division. Most employees reside in a single department however, the company has "rovers" that aren't assigned any department. Each division has a single manager and each department has a single manager. Employees cannot manage more than one division or department. Each employee has a unique id$,$ name, address, date hired, and annual salary. Departments are identified by their ID$,$ name, location, and extension. Employees are assigned to projects along with other employees. Employees must be assigned at least one project and can have different billing rates for different projects. If a project doesn't have any employees assigned it is cancelled. Projects have a projectid, start date end date, and estimated cost. A department has a uniqueid, name, location, and phone. A division has a uniqueid and name.