![]() | |
#1
| |||
| |||
|
#2
| |||
| |||
|
|
“Cars may be uniquely identified by their registration number. Other |
#3
| |||
| |||
|
|
“Cars may be uniquely identified by their registration number................................ |
#4
| |||
| |||
|
|
Cars may be uniquely identified by their registration number. Other data of interest concerning our cars includes: year of manufacture, VIN (unique vehicle identification number) 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 We work with different service stations. Each service station has the capacity to service any of our cars. Service stations are identified by a unique number. We also require details about the service station such as: name, address, telephone and contact person. We personally choose a particular service station at a given time based on a number of factors which are not required to be stored in the system. When a service station is chosen, a booking is made with that station. The information we require about these bookings includes: car registration number, service station number, date in, date out, service type (e.g. 20,000km service or 50,000km service etc.), 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. User 2: Car Rental Booking Department. Each of our clients is assigned a unique client number. Other information we store about clients includes their name, address, telephone number and discount category. There are three discount categories which we use in conjunction with the standard rate for the car to calculate the final price for a rental booking. When a client makes a booking for a car, we store the following information for the booking: client number, car registration number, date required, date delivered, date due, date returned, kilometres when delivered, kilometres when returned, rental rate (depends on the type of the car), drivers license number of the driver (since our clients may be companies), and amount due. We also need to record the amount due for car insurance. This amount varies depending on the age of the driver and the type and age of the vehicle rented. The final price for the rental booking is the sum of the rental rate and the insurance due. When I look up information on available cars, I need to view the following information: car registration number, year of manufacture, manufacturer and model, kilometres travelled and comments on the condition of the car. We keep all the booking data for the cars in the system, not just bookings which are currently active ( i.e. bookings for cars which have not yet been returned). Draw initial local Entity-Relationship diagrams for each user view. To what level of the ANSI/SPARC architecture do these diagrams correspond? Document all the entities, relationships (including cardinality), attributes, domains, candidate keys and primary keys. State explicitly any assumptions you make at this point. Merge the local Entity-Relationship diagrams into a single global data model (assuming that these two local views define the entire scope of the system under consideration). To what level of the ANSI/SPARC architecture does this diagram correspond? Again, state any assumptions you make at this point and document all the working involved in generating this diagram. Show that each local user view is completely derivable from this global data model. Derive relations from the global Entity-Relationship diagram you have just generated.Normalise the relations to BCNF. Show all working involved in the normalization process.Document the final BCNF relations in DBDL (Database Design Language). Define appropriatereferential integrity update rules (state any assumptions you make here concerning the business processes which may imply these rules). -- Posted via http://dbforums.com |
![]() |
| Thread Tools | |
| Display Modes | |
| |