In our sample application, we are going to implement a hotel booking system. The following flow diagram shows the process for the booking system used in our application. When a customer arrives, the front desk executive will enquire for a room type based on the customer's choice. If the room is available, the front desk executive will create a customer record in the application, assign a room to the customer, and set the check-in and check-out dates. On the check-out date, a bill will be created for the customer, and the room will be free.
In our sample application, we will be using the following main entities: