1. Database Design & Implementation Workshop 4 – Drawing ER Diagrams
Draw Degree, Type & Participation diagrams that depict each of the following relatively simple ‘real-world’ situations:
 A member of staff must work in a department, and there are many members of staff in each department.
Several buses can park in the garage, and each bus may cover any number of routes.
Each producer is in charge of several plays and there are several actors appearing in each play. At any one time an actor may be involved in more than one play.
An operator can work on many machines and each machine has many operators. Each machine belongs to one department, but a department can have many machines.

2. ER Diagram Elements Entity
Entity = a singular noun, enclosed in a box.
Relationship = a solid line, with rounded ends.
type =>
Type = a verb, or verb phrase.
NB. MUST indicate the Type in BOTH directions.
<= type 1
Degree = only two possibilities. M
Compulsion = a vertical line, within an Entity.

3. Staff Department Work in => 1 M <= Has
a) A member of staff must work in a department, and there are many members of staff in each department.
Work in =>
Staff
Department 1 M
<= Has

4. b) Several buses can park in the garage, and each bus may cover any number of routes.1
Bus
Garage
<= can accommodate 1
=>
Can be covered by
May cover
=> M
Route

5. c) Each producer is in charge of several plays and there are several actors appearing in each play. At any one time an actor may be involved in more than one play. 1
produces=> M
Producer
Play
<=are produced by 1
is acted by=> M 1 M
Actor
Act/Play
acts in=>

6. d) An operator can work on many machines and each machine has many operators. Each machine belongs to one department, but a department can have many machines. M m 1 1
<= has
<= has
dept
Mac/op
machine
Belongs to => M
Work on => 1
Example d
operator