Relationship for college database, Database Management System

Using the concepts defined previous, we have identified that strong entities in COLLEGE database are FACULTY, STUDENT, COURSE and DEPARTMENT. This database also has one weak entity known as GUARDIAN. We can states the following relationships:

1. Head-of is a 1:1 relationship among FACULTY and DEPARTMENT.

Participation of the entity FACULTY is partial since not all the faculty members participate in this relationship, as the participation from department side is total, as every department has one head.

2. Works_in, is a 1:N relationship among DEPARTMENT and FACULTY.

Participation from both sides is total.

3. Opts, is a 1:N relationship among COURSE and STUDENT. Participation from student side is total because we are assuming that every student enrolled opts for a course. However the participation from the course side is partial, as there can be courses that no student has opted for.

4. Taught_by, is a M: N relationship between FACULTY and COURSE, as a faculty can teach a lot of courses and a course can be taught by a lot of faculty members.

5. Enrolled, is a 1: N relationship among STUDENT and DEPARTMENT as a student is allowed to enroll for only single department at a time.

6. Has, is a 1:N relationship among STUDENT and GUARDIAN as a student can have more than one local guardian and one local guardian is supposed to be related to one student only. The weak entity Guardian has total participation in the relation "Has".

Posted Date: 3/6/2013 6:21:56 AM | Location : United States







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