We do have something similar to what you describe, thought not exactly the same. You can search for items in a particular Zip Code, by using the "options" link next to the search box on our home page. You can enter either 5, 4, or 3 digits as your search criteria, thus broadening the area covered. Admittedly, it would be nice to be able to specify something like "100 mile radius of zip 12345", but we do not currently have that programmed. It would require a pretty massive database to allow such matching, but if anyone knows of an easily available database of this nature, please let us know.
Smatsui, If you click on the zip code on the ad at the top right it gives the location & also has a map feature most of the time.
Audiogon, as for zip code 12345, it's in upstate NY. I had a deal with someone at that zip but don't remember the city.
Actually Audiogon, as a database administrator I believe the change would perhaps only require disk space for some additional indexes.
Good idea, Smatsui.
I'm not sure you're correct there Stehno. Zip codes do not have any sort of distance information built into them, nor are they a standard size, so that is additional data required and processing time to figure out what zipcodes are within X miles of the zip code you entered. You could avoid the additional processing time by fixing the distances offered and precalculating the distance between zip codes and saving them in a table for lookup instead of dynamically calculating them, but that would give much rougher results since it would average distances between zips and ignore real road distances. The speed would probably be slower but not that much since you would be changing from an SQL statement of the form:
WHERE ZIP BETWEEN 91200 AND 91299
Instead of the slower:
WHERE ZIP IN (91234, 91233, 91232, ...)
Assuming the zips are stored as numbers and not as strings, which may or may not be a valid assumption.
I personally would be incredibly happy if they would allow us to filter by two digit zip codes instead of three. Here in the SF bay area we have so many zip codes in close proximity, I find I have to 20 individual searches to comb my local area, which is tedious to the point of tears.
Audiogon, why not grab the latitude and longitude associated with a zip code when a seller inserts an item for sale into the database. For instance, my zip code is 19144, so if I were to sell something, the Audiogon backend software would so out to http://www.census.gov/cgi-bin/gazetteer?zip=19144 and retrieve the latitude and longitude (40.033773 N, 75.173099 W in my case) and put it in two extra fields in the database. Then, if you do a search from a particular zip code, look up that zip codes lat/long, calculate the criteria of latitude and longitude that would fall in that radius, and query the database for items with lat/long that match that criteria.
Hopefully med school hasn't fried my brain too much so I can still remember enough from my software engineer days.
If sellers had to list their area code when they list, an area code search could be added in addition to the zip code search. Your local phone directory has a map with all the area codes.
Let's keep it simple. All we really need is a way to enter MULTIPLE 3-digit zip code prefixes (20, 30, however many it takes), and get back a list sorted by catagory. (And please be bookmarkable so it only has to be entered once).
That would fully satisfy me.
This web site will give you a list of zip codes within a given radius of a zip code:
(By the way, what about Canada? Do any Canadians use Audiogon?)
The telephone area code should do nicely for indexing by local region.
Justdan, I'm from Canada and I believe this system wouldn't be very useful for Canadians. There simply isn't enough people to warrant the need. If Audiogon is at it, then it would be nice to see it, but it would just be icing on the cake!
I was thinking of that latitude and longitude approach last night also, especially since it wouldn't be that hard to implement. I think that would be a pretty reasonable approach.
Check with the autotrader.com people - they seem to have a database that does this.
12345 is Schenectady, New York