Relational schema, Database Management System

crete a data base relationship model

Entity:

  1. Students;
  2. Professors;
  3. Dormitories buildings;

Attributes of students:

  1. Name;
  2. Address;
  3. Dorm;
  4. Room number;
  5. Stu dent advisors;

Relationship ratios:

  1. One to One- student to advisor;
  2. One to Many (1: N)-advisor to students;
  3. Many to Many (n: M)- students to their advisors;

Foreign keys

This is the referencing relation of the column i.e. student advisor

Primary keys

They identify the column i.e. the Sname.

Assumptions

  1. Only single attributes are mentioned for the database because the database is made by single attributes
  2. Concepts represented by entity, relationship or attributes type  are represented by capital letters
  3. Key property (k) types which is a attribute of property (p) can be determined by P and vice versa
  4. Verticals line separate the  main attributes of the relation
  5. Each attributes is an atomic; a distinct line attributes
  6. Each of the tuples carry single phone numbers of both students and advisors
Posted Date: 2/21/2013 1:21:07 AM | Location : United States







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