In: Computer Science
You are hired to design a database for a fitness center. As the fitness center is expanding with more than one branch, they want to create a database to keep track of its customers, facilities and employees. Each branch has a unique id and address (building number, street, district, and city). A branch may have more than one facility (e.g. swimming pool, spa, etc.). Each facility must belong to only one branch, and the information for a facility is name and fees. In addition, each fitness branch offers different classes (such as Yoga, Pilates, Zumba, etc.). All classes should be led by at most one trainer, who is an employee.
Employees must work at one and only one branch. Each employee has an id, name, address (building number, street, district, and city) and can have multiple phone numbers. An employee can only be an admin, managing the facility or working as a clerk, or a trainer. An employee cannot be a trainer and an admin because the trainer id compensated an hourly wage while an admin staff paid a monthly salary. Trainers can train individual customers at different time sessions.
A customer must register at one branch. Each customer has a membership number, name (stored as first name and last name), email, and only one phone number. A customer can join more than one class or uses any number of facilities. A customer may also decide to be trained by at most one personal trainer.
Given the above description:
Entities used:
1. Category/Fitness
2.Branch
3. Facilites
4.Classes offered
5.Facilites offered
6. Employee
7. Trainer
(since trainer, gets paid on weekly bases)
8.Customer
b) Each key has its own PRIMARY KEY, called ID.
C) Cardinality used: one- one relationship,
one- to- many relationship and
many- to - many relationship
you can find it in the picture below
D) constraints are drawn clearly in the ERD diagram
Check this ERD diagram and Please do the thumbs up.