<<<<Everything snipped>>>>
David, is it at all intuitive to organize your geography into a tree-type
structure? Here is an example:
Western Hemisphere (hemisphere)
C. America (continent)
Guatemala (country)
N. America (continent)
Canada (country)
Manitoba (state/province)
Moose
Elk
Cuba (country)
Cuba (island)
Aligator
United States (country)
Montana (state/province)
Moose
Florida (state/province)
Dade (county/parish)
Aligator
Mexico (country)
Chihuahua (state/province)
Desert Rat
S. America (continent)
Brazil (country)
Amazon (river)
Pirhana
Peru (country)
Argentina (country)
Galapagos Is (island)
Galapagos Tortise
With this kind of structure, it is simple to answer questions like:
a) List all of the places to find Aligators
b) Which animals can be found on Islands in the Western Hemisphere?
c) List all animals found in Brazil.
Any type of question that deals with "containment" can be answered from a
data structure like this. Your flat table model will not work for this
type of information. (List the continents in the Western Hemisphere, list
the countries on the continent "S. America",...)
You cannot make your site easy to manage with just a flat data structure.
Sorry, but that is my professional opinion.
For instance, to solve the question of "what countries will I find an
Aligator", you find all of the nodes for Aligator then move "up" the tree
until you find a "country" node for each one. You may need to move up 1 or
2 or more nodes until you get to a "country" but you will eventually get
to one. Keep a list of the countries you find. When you are done, simplify
your list so that each country only appears once. There's the answer. Make
sense?
Shawn Green
Database Administrator
Unimin Corporation - Spruce Pine
Shawn Green
Database Administrator
Unimin Corporation - Spruce Pine
