geospatial

Given a database that contains three fields: Latitude Longitude Proximity Where Lat and Long are GPS coordinates, and Proximity is (some unit - feet? Seconds? Minutes?) And given the user's current GPS lat/long... I want to write a SQL query that will retrieve all rows where the user is within "Proximity" of those rows. And the trick: This has to work in SQLite, which only supports fairly primitive data types. No cheating and relying on SQL Server (or some other product that provides better geospace functions). Any suggestions? Don Jones Here is a C-based custom function for sqlite [copied

Using Maxmind's GeoIP software, we can narrow down the LONG/LAT of an IP address to relative accuracy within 25 miles around 80% of the time. Now, we don't want to use any of the other information provided by MaxMind, because there are a lot of discrepancies between feature names, i.e., cities, to perform a look up. We plan on attempting such a look up if other methods fail to locate a feature, but for performance reasons, look ups on floats are much faster than strings. Now, I'm a little clueless on how we can find the closest matching LAT/LONG given from Maxmind to our database. The problem