crete a data base relationship model
Entity:
- Students;
- Professors;
- Dormitories buildings;
Attributes of students:
- Name;
- Address;
- Dorm;
- Room number;
- Stu dent advisors;
Relationship ratios:
- One to One- student to advisor;
- One to Many (1: N)-advisor to students;
- 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
- Only single attributes are mentioned for the database because the database is made by single attributes
- Concepts represented by entity, relationship or attributes type are represented by capital letters
- Key property (k) types which is a attribute of property (p) can be determined by P and vice versa
- Verticals line separate the main attributes of the relation
- Each attributes is an atomic; a distinct line attributes
- Each of the tuples carry single phone numbers of both students and advisors