haroonabbasi / MySQL-distance-between-GPS-coordinates

This MySQL function adds DISTANCE() to calculate the distance between two GPS locations using the Haversine formula

MySQL Distance Between GPS Coordinates

This MySQL function adds DISTANCE() to calculate the distance between two GPS locations using the Haversine formula.

Function Signature

/*
 * @param lat1  (double)   latitude of origin
 * @param lon1  (double)   longitude of origin
 * @param lat2  (double)   latitude of destination
 * @param lon2  (double)   longitude of destination
 * @param unit  (enum)     MILE, MI for miles or KILOMETER, KM for kilometers
 * @return      (double)   Distance between the two points in the units specified.
 */
FUNCTION DISTANCE( lat1 DOUBLE, lon1 DOUBLE, lat2 DOUBLE, lon2 DOUBLE, unit ENUM( 'MILE', 'KILOMETER', 'MI', 'KM' ) )

Example usage

Calculate the distance between San Francisco, CA and New York, NY in miles

mysql> SELECT DISTANCE( 37.7756, -122.4193, 40.71448, -74.00598, 'MI' );
2565.80921930121

Find the two closest cities (in our table) to Paris, France

mysql> SELECT city, country FROM cities ORDER BY DISTANCE( 48.856638, 2.352241, cities.lat, cities.lon, 'KM' ) ASC LIMIT 2;
Geneva       Switzerland
Barcelona    Spain

Caveat

This calculates the 'straight line' distance, so it will likely be shorter than the driving distance (because roads are not generally straight lines between points).