1. Entity-Relationship Diagram

2. Entity-Relationship Diagram (1/3)
E-R Diagram Symbols
Entity Set
Relationship 1 N
Attribute
Functionality

3. Entity-Relationship Diagram (2/3)
E-R Diagram Symbols (Cont’d) 1
Married-to
(Monogamy)
Men 1
Women
One-to-one relationship 1
Advised-by
Faculty N
Students
One-to-many relationship N
Taken-by N
Students
Courses
Many-to-many relationship

4. Entity-Relationship Diagram (3/3)
Example F# S#
Advised-by
Faculty 1 N
Students
FName
SName 1 N
Taught-by
Taken-by N N
Courses C#
CName

5. Composition by eliminating one-to-many relationship relations
Relational Schema
Universal Relation  decomposition
Composition by eliminating one-to-many relationship relations
Faculty (F#, FName)
Students (S#, SName)
Courses (C#, CName)
Advised-by (F#, S#)
Taken-by (S#, C#)
Taught-by (F#, C#)
Faculty (F#, FName)
Students (S#, SName, F#)
Courses (C#, CName, F#)
Taken-by (S#, C#)

6. Queries
List the all the names of the students who are taking the classes that Prof. Suh, Euiho is teaching
List the all the names of the students who are advised by the professors who are teaching the classes taken by Hong, gildong

7. 2. Revise the relational schema
April Exam Questions
Suppose that (1) Adviser-Advisee relationship’s functionality is many-to-many, and (2) A specific place is assigned when a professor meet his/her advisee. In another word, the meeting place depends upon the unique combination of a professor and a student.
1. Revise the E-R
2. Revise the relational schema
3. Relational algebraic expression for a query
(The query will be given in the exam)