Quick question for the experts.

I have a huge database. There is the company table which has all companies and references to several other tables. I was just asked to create something new called zones.
Let's say Chicago is a zone so then so then I'd like Skokie, Lincolnwood, Des Plaines to all be part of it's zones. This is how I designed the database. Before I go with it I just want to see if it makes sense.
I'll have one table which lists the zones
1 Chicago
2 Brooklyn
3 Milwaukee

etc.

I'll have another table which defines the zones

1 Lincolnwood
1 Skokie
2 Sea Gate

etc.

I will then have the zone ID in the company table.

Does this make sense?
Thanks

Well, that approach makes sense, but you could cut down on the number of tables if you simply made the zone NAME be the zone id rather than a number, unless there is some need to have the number instead of the name. In that way, your second table would look like this, and you wouldn't need a table to translate the zone number to it's name:

Lincolnwood Chicago
Skokie Chicago
Des Plaines Chicago
Sea Gate Brooklyn

and so on... basically for every entry there would be an associated zone. This way you could join your company table via the town name and be provided with the proper zone, without having to do a second lookup to get the zone name from the id. This becomes a simple look-up table that provides the zone name directly.

This makes total sense!!!Ever heard of Normalisation in Databases. It will help a lot.

This is what you are doing on the zone and sub-zone example.