Question

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: (answer me with keyboard write . . I could not understand the hands write )

1. Draw an ERD for the database, identifying the following:
   1. All the entities, attributes and relationships
   2. Primary key and (discriminator in weak entity, if any). Don’t forget each entity has to have PK.
   3. Participation and cardinality constraints. (Explain your choices for two constraints- i.e. identify the words the guided your decision)
   4. Specialization and completeness constraints (if there is an ISA relationship).

2. Write a schema for two entities and two relationships of your choice. Remember, sometimes a relationship is better not be represented in a separate schema; if this is the case with your chosen relationship explain what you will do.
3. Please use a tool to draw the ERD such as https://app.diagrams.net/ . (answer me with keyboard write . . I could not understand the hands write ) ( I need complete answer and clear draw )

Answer 1

E-R Diagram-

• This Er model has 10 main entities-

1. facilities
2. branch
3. classes
4. Customer
5. employees
6. manager
7. admin
8. clerk
9. trainer
10. Address

• This Er model has has been converted into 3NF
• Here each entity and its attributes are in tabular form
• Data types of each attribute has been mentioned with it
• The primary key as PK and foriegn key as FK has been mentioned there.
  

If any doubt, please feel free to ask and comment, i would like to answer them.
Thank you