Question: Putting Data Into 3rd Normal Form
Date: Sat, 14 Apr 2001 20:50:21 +0100
Message-ID: <9ba9kq$rm9$1_at_newsg1.svr.pol.co.uk>
Thanks in advance for any suggestions and constructive criticisms on what I
have attempted so far.
( and yes, it does relate to a college assignment )
A vehicle-rental company
The full scenario includes data on staff, offices and so on but, I want to ask about one part of this.
The company rents out 2 types of vehicle - "car" and "van"
For each Vehicle - the following data is collected
Registration Number
Manufacturer Name
Model
Engine Size
Passenger Capacity
Current Mileage
current location
daily hire rate
date of next MOT inspection
( In Britain - MOT inspection is a mandatory annual inspection all vehicles
My attempt to produce 3rd Normal Form has produced the following tables :
TBL_VEHICLE
TBL_MODEL_DETAILS
have to undergo from its 3rd year )
Reg_number (PRIMARY KEY)
engine_size
date_MOT_due
current_mileage
current_location
model_code
model_code (COMPOSITE PRIMARY KEY)
Manufacturer_name (COMPOSITE PRIMARY KEY)
Model_name (COMPOSITE PRIMARY KEY)
passenger_capacity
daily_hire_rate_code
vehicle_type ( C for "car" V for "van" )
TBL_HIRE_RATE
daily_hire_rate_code (PRIMARY KEY)
amount
Specific questions:
- It is "better" to include an additional table, linking hire rate to vehicle model - something like:
TBL_HIRE_RATE_FOR_MODEL
model_code (COMPOSITE PRIMARY KEY)daily_hire_rate_code (COMPOSITE PRIMARY KEY)
2: What would be the best way of separating "manufacturer" into its own table ?