Data modeling issues for a travel planning system

I need help in designing a data model for a travel planning system for tourists to visit attractions via underground railway. Basically there are 4 entities (tables):

STATION:
- (PK) statname (the name of the station)

• interchange (Y = interchange station, N = non-interchange station)

LINE:
- (PK) linename (the name of the line)

STATION_LINE:
- (PK) linename (the name of the line)

• (PK) statname (station name)
• (PK) direction (the name of the terminal station as the direction)
• nextstatname (the name of the next station)

ATTRACTION:
- (PK) attrname (attraction name)

• (FK) nearstat (the station which is nearest to the attraction)
• distance (the distance between the attraction and its nearest station)

Inputs to the system:
1. starting station
2. the attraction to visit

Outputs from the system:

1. the start line to use
2. interchange stations
3. the nearest end station on a particular line
4. the time taken to walk from the tube station to the attraction
5. the total time taken to travel to the attraction

In additon, there are 2 assumptions:
1. It takes on average 2 minutes to travel between adjacent stations 2. 10 minutes to change lines at an interchange station

Please help me to improve the quality of my data model to fulfill the requirements.

Thanks a lot!!

Henry Received on Fri Nov 04 2005 - 09:10:01 CET