Re: er-diagram

Looks correct but you should also identify foreign keys in the table attributes list. You have them there but there not identified as such. Good habit to get into. Makes it real easy for someone else to work with the database later.

Chris wrote:

> Hi,
> I've got the following er-diagram, entities and attributes (see attachment)
> according to the following interview it is a car company:
> Is my work correct?
>
> Thanks for your help
>
> Chris
> "Cars are uniquely identified by their registration number. Other data
>
> of interest concerning our cars includes: year of manufacture,
>
> manufacturer and model, kilometres travelled, date last serviced (so we
>
> can tell when a car is due to be serviced) and comments on the
>
> condition of the car. Additionally, each car is classified into one
>
> particular type. The types of car we have are listed below:
>
> small manual
>
> small automatic
>
> medium manual
>
> medium automatic
>
> large manual
>
> large automatic
>
> commercial vehicle
>
> We work with different service centres. Each service centre has the
>
> capacity to service any of our cars. Service centres are identified by a
>
> unique number. We also require details about the service centre such
>
> as: name, address, telephone and contact person. We personally
>
> choose a particular service centre at a given time based on a number of
>
> factors which are not required to be stored in the system. When a
>
> service centre is chosen, a booking is made with that centre. The
>
> information we require about these bookings includes: car registration
>
> number, service centre number, date in, date out, service details,
>
> amount due and amount paid. So that I check if a car is available to
>
> be serviced, I need to be able to view the following data about client
>
> rental bookings for cars - car registration number, client number, date
>
> out and date due."
>
>
>
>
Received on Sat Apr 06 2002 - 12:25:03 CEST