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.

A. A member of staff must work in a department, and there are many members of staff in each department. DepartmentStaff Member M <=Works Provides Work Spaces => 1 Staff Department 1 M Works in Staff

B. Several buses can park in the garage, and each bus may cover any number of routes. Bus/Rou Route Bus Garage Driver covers => Covered by => Can accommodate => Is parked in=> M M Is part of => <= Driven By 1 Team 1 M 1 1

B. Several buses can park in the garage, and each bus may cover any number of routes. Garage RouteBus MM M 1 B/R M M

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. Producer Has => 1 PlayPl/ AcActor In charge=> <= run by 1MMM1 <= Stars in Actor Act/PlayPlay Producer 1MM1 1 M <= Has Acts in => Produces => <= Has

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. Producer Has => 1 PlayPl/ AcActor In charge=> <= run by 1MMM1 <= Stars in Actor Act/PlayPlay Producer 1MM1 1 M <= Has Acts in => Produces => <= Has

Operator Op/Ma Department Machine has => Belongs to =><= works on 1 1 1M M M <= used by 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.

Ope Ope+Mac Mac Dep 1 M M M M M 1 1