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79

answers:

1

I have a PlaceID | PlaceName | Lat | Lon as my database structure.

Say I have my current latitude and longitude as

$lat = "37.331862";
$lon = "-122.029937";

I want to find places that are in a 100 feet radius. Might allow the user to choose.

+4  A: 

You may be interested in checking out the following presentation:

The author describes how you can use the Haversine Formula in MySQL to order by proximity and limit your searches to a defined range. He also describes how to avoid a full table scan for such queries, using traditional indexes on the latitude and longitude columns.


1 PDF Version

Daniel Vassallo
Very nice paper, thanks for sharing!
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