Question

Draw an ERD diagram for Hair Saloon and describe its relationship

Answer 1

The resultant entity relationship diagram has five entities. First entity is customer. Customer has attributes naming customer ID, customer name, age, and gender. Customer ID is primary key here. Second entity is employee. Employee has attributes naming employee ID which is primary key, gender, address, and pay. Third entity is services. Services has attributes naming service ID which is a primary key , service name, service duration, materials required and price. Fourth entity is appointment which keeps track of of all the appointments made by the customer in the hair salon. It has attributes naming appointment ID, date, time and service Id, where appointment ID is a primary key. The last entity is service provisioning. This entity has the record of the services which have been performed until a particular time it has attributes named service ID, and service time.

Customer and appointment entity has a 'makes' relationship in which customer makes an appointment and one customer can make one or more appointments. Employee has a relationship with service provisioning entity where a service provisioning is performed by I an employee. One service can be performed by multiple employees and one employee cand provision multiple services. Appointment has relationship name 'Provision for' with service provisioning where each service provisioning is provisioned for a particular appointment. One service provisioning can be performed for one appointment only so it is a one to one relationship. Services entity has a undergoes relationship with service provisioning. One service can be provisioned multiple times due to multiple appointment of the same service, so it is a one to many relationship.