Develop an EER model for the following situation using the traditional EER notation, the Visio notation or the supertypes notation.
An international school of technology has hired you to create a database management system to assist in scheduling classes. After several interviews with the president, you have come up with the following list of entities, attributes, and initial business rules:
- Room is identified by Building_1D and Room_NO and also has a Capacity. A room can be either a lab or a classroom. If it is a classroom, it has an additional attribute called Board_Type.
- Media is identified by Mtypeid and has attributes of MediaType and TypeDescription. Note: Here we are tracking type of media (such as VCR, projector, etc.) not the individual piece of equipment. Tracking of equipment is outside the scope of this project.
- Computer is identified by Ctypeid and has attributes ComputerType, TypeDescription, DiskCapacity, and ProcessorSpeed. Please note: As with Media Type, we are tracking only the type of computer, not an individual computer. You can think of this as a class of computers (e.g., PIII 900MHZ).
- Instructor has an identifier Emp_ID and has attributes Name, Rank, and Office Phone,
- Timeslot has identifier TSIS and has attributes DayofWeek, StartTime, and EndTime.
- Course has identifier CourseID and has attributes CourseDescription and Credits. Course can have one, none or many prerequisites. Courses also have one or more sections.
- Section has identifier SectionID and attribute EnrollmentLimit
After further discussions, you have come up with some additional business rules to help you create the initial design:
- An instructor teaches one, none or many sections of a course in a given semester.
- An instructor specifies preferred time slots
- Scheduling data are kept for each semester, uniquely identified by semester and year.
- A room can be scheduled for one section or no section during one time slot in a given semester of a given year. However, one room can participate in many schedules, one schedule, or no schedules; one time slot can participate in many schedules, one schedule, or no schedules; one section can participate in many schedules, one schedule or no schedule. Hint: Can you associate this to anything that you have seen before.
- A room can have one type of media, several types of media, or no media.
- Instructors are trained to use one, none, or many types of media
- A lab has one or more computer types. However, a classroom does not have any computers.
- A room cannot be both a classroom and a lab. There also are no other room types to be incorporated into the system.