Location: [CPSC 333] [Ongoing Examples] [Student Information Systems] Version One
This page was most recently modified on February 4, 1997
This system will be used to keep track of the students that are registered in or that have completed some (single, fixed) academic course.
In order to meet requests for information, it is necessary to keep track of the ID number and name (first name, middle initial, and family name) of each student that the system knows about. ID numbers are unique; that is, no two students have the same ID number. Names are not necessarily unique.
This is a pass/fail course. Students who fail from the course are automatically registered in the next section of the course. That is, they remain registered. Students may repeat the course as often as they'd like before they pass it, so it isn't necessary for the system to keep track of the number of times the student has attempted (and failed) the course. Students may not repeat the course after they've passed it.
A student can ``withdraw'' from the course if she or he hasn't passed it yet. It isn't necessary to keep track of students who have withdrawn from the course (partly, because they can register in the course again later on, if they choose to, whether they've withdrawn from the course before or have never registered in the course before at all).
It is necessary for the system to remember any given student that has already passed the course (until the system is told to delete this information). In particular, it should be possible for a user to give the system an ID number and for the system then to report either that
If the ID number belongs to a currently registered student or to a student who has (recently) passed the course, then the system should also be able to supply the student's name.
It should also be possible to
Since the people or other systems providing information might occasionally make mistakes (by providing incorrect information), it should also be possible to
Finally, it should be possible to request that information about some students be deleted from the system: Given an ID number, the system should provide a report listing the ID numbers, names, and statuses for all known students whose ID numbers are less than or equal to the one that has been given, and then delete the information it maintained about them. For safety reasons, the system should refuse to do this if the given ID number is ``too new,'' and it should also alert the user and make no change if the given ID number is so old that the information corresponding to this request has been deleted already (we'll worry about these details later).
This system will be used one or more times as an example during lectures:
Location: [CPSC 333] [Ongoing Examples] [Student Information Systems] [Version One]