Draw E-R diagrams demonstrating each of the following relationships (create three meaningful examples for each relationship): One-to-One, One-to-many, One-to-Optional Many, Optional Many-to-One, Optional Many-to-Optional Many. Show the relationships horizontally.
For each E-R diagram, state the relationship in words (for both, the forward path and the backward path).
A. Each employee is assigned to one and only one office. Each office is occupied by one and only one employee.
B. Each cargo aircraft will serve from one to many distribution centers. Each distribution center is served by one and only one cargo aircraft.
C. One systems analyst is assigned to anywhere from zero to many projects. Each project will be developed by one and only one systems analyst.
D. One machine is undergoing anywhere from zero to one scheduled maintenance. Scheduled maintenance is being done to one and only one machine.
E. Each salesperson is assigned to anywhere from one to many customers. Each customer may have from one to many salespersons.
F. One home office has one to many employees. Each employee may be assigned from zero to one home office.
G. Each passenger is flying to many destinations. Each destination will be visited by many passengers.