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Example A university registrar’s office maintains data about the following entities: (a) courses, including number, title, credits, syllabus, and prerequisites; (b) course offerings, including course number, year, semester, section number, instructor(s), timings, and classroom; (c) students, including student-id, name, and program; and (d) instructors, including identification number, name, department, and title. Further, the enrollment of students in courses and grades awarded to students in each course they are enrolled for must be appropriately modeled. Construct an E-R diagram for the registrar’s office.Document all assumptions that you make about the mapping constraints. Sunday, January 13, 2019Sunday, January 13, 2019
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Entity sets student ---- sid, name, program
instructor --- id, name, dept, title course --- syllabus, courseno, title, credits, prerequisites course-offering --- secno, year, semester, time, room course-offering is a weak entity set dependent on course Sunday, January 13, 2019Sunday, January 13, 2019
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Relationship sets enrols --- each student can enroll in several courses, grade must be kept relationship attribute --- grade teaches --- an instructor can teach several sections is-offered --- multiple sections of a course may be offered requires --- prerequisite, maincourse Sunday, January 13, 2019Sunday, January 13, 2019
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Sunday, January 13, 2019Sunday, January 13, 2019
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Reducing the E-R diagram to tables
Entities student table course sid name program courseno title syllabus credits Sunday, January 13, 2019Sunday, January 13, 2019
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instructor course-offerings iid name dept title courseno secno year
semester time room Sunday, January 13, 2019Sunday, January 13, 2019
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Relationships enrols teaches requires sid courseno secno semester year
grade courseno secno semester year iid maincourse prerequisite Sunday, January 13, 2019Sunday, January 13, 2019
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