For each scenario below you are to create a complete and accurate entity-relationship diagram.
In your documentation, please start each new problem on a new page.
Label the problem number and re-state what you are doing for the problem (as an introduction to your ERD). DO NOT just copy and paste the problem text. Instead, write a single complete paragraph in your own words that introduces the problem and its characteristics (the entities you dont need to list the attributes in your introduction).
You will draw your ERD using DIA, VISIO, or other diagramming software. Take a screen shot of the finished diagram and include it in your document below the introductory paragraph. You may rotate the diagram 90 degree and/or use a new page to make it fit. Remember that clarity and readability are important.
Problem #3 – The City of Williamsburg Kentucky wants to maintain information about its system of schools, including its teachers and their college degrees, its students, administrators, and the subjects that it teaches.
Each school has a unique name, an address, telephone number, year built, and size in square feet. Students have a student number, name, home address, home telephone number, current grade, and age. Regarding a students school assignment, the school system is only interested in keeping track of which school a student currently attends. Each school has several administrators, such as the principal and assistant principals.
Administrators are identified by an employee number and also have a name, telephone number, and office number. Teachers are also identified by an employee number and each has a name, age, subject specialty such as English (assume only one per teacher), and the year that they entered the
Teachers tend to move periodically from school to school and the school system wants to keep track of the history of which schools the teacher has taught in, including the current school. Included will be the year in which the teacher entered the school, and the highest pay rate that the teacher attained at the school. The school system wants to keep track of the colleges that each teacher attended, including the degrees earned and the years in which they were earned. The school system wants to record each colleges name, address, year founded, and Internet URL (address).
Some teachers, as department heads, supervise other teachers. The school system wants to keep track of these supervisory relationships but only for each teachers current supervisor. The school system also wants to keep track of the subjects that each school offers (e.g., French I, Algebra III, etc.). Each subject has a unique subject number, a subject name, the grade level in which it is normally taught, and the year in which it was introduced in the school system. The school system wants to keep track of which teacher taught which student which subject, including the year this happened and the grade received.
Problem #4 You have been hired by Patriot Electronics (PE), a company that repairs smartphones, laptops, tablets, computers, and MP3 players. The CEO wants you to create a database to help run the business. Create an ERD to capture the following business rules: When a customer brings a device to PE for repair, data must be recorded about the customer, the device, and the repair. The customers name, address, and contact phone number must
be recorded (if the customer has used the shop before, the information already in the system for the customer is verified as being current).
For the device to be repaired, the type of device, model and serial number are recorded (or verified if the device is already in the system). Only customers who have brought devices into PE for repair will be included in this system. Since a customer might sell an older device to someone else who then brings the device to PE for repair, it is possible for a device to be brought in for repair by more than one customer. However, each repair is associated with only one customer. When a customer brings in a device to be fixed, it is referred to as a repair request, or just repair, for short. Each repair request is given a reference number, which is recorded in the system along with the date of the request, and a description of the problem(s) that the customer wants fixed. It is possible for a device to be brought to the shop for repair many different times, and only devices that are brought in for repair are recorded in the system. Each
repair request is for the repair of one and only one device. If a customer needs multiple devices fixed, then each device will require its own repair request. There is an established number of repair services that PE performs. For each repair service, there is a service ID number, description, and charge. Charge is how much the customer is charged for the shop to perform the service, including any parts used. The actual repair of a device is the performance of the services necessary to address the problems described by the customer. Completing a repair request may require the performance of many services. Each
service can be performed many different times during the repair of different devices, but each service will be performed only once during a given repair request. All repairs eventually require the performance of at least one service, but which services will be required may not be known at the time the repair request is made. It is possible for services to be available at PE but that has never been required in performing any repair. Some services involve only labor activities and no parts are required, but most services require the replacement of one or more parts. The quantity of each part required in the performance of each service should also be recorded. For each part, the part number, part description, quantity in stock, and cost are recorded in the system. The cost indicated is the amount that PE pays for the part. Some parts may be used in more than one service, but each part is required for at least one service.