geo_zip_dist stored proc.sql

CREATE PROCEDURE geo_zip_dist (IN center_zip int, IN dist int)

BEGIN
declare center_lon float; declare center_lat float;
declare lon1 float; declare lon2 float;
declare lat1 float; declare lat2 float;

-- Lookup the original lon and lat for the zip
select lon, lat into center_lon, center_lat from zips
 where zip=center_zip;

-- calc lat and lon for the rectangle
set lon1 = center_lon-dist/ABS(COS(radians(center_lat))*69);
set lon2 = center_lon+dist/ABS(COS(radians(center_lat))*69);
set lat1 = center_lat-(dist/69);
set lat2 = center_lat+(dist/69);

-- create temporary table
-- DROP TABLE local_zips;
CREATE TEMPORARY TABLE IF NOT EXISTS local_zips  (
     zip int not null,
     distance double,
     primary key (zip)
);
TRUNCATE local_zips;

-- run the query and insert into temp table
INSERT INTO local_zips
 SELECT dest.zip,
 3956 * 2 * ASIN(SQRT( POWER(SIN((orig.lat - dest.lat) * pi()/180 / 2), 2) +
 COS(orig.lat * pi()/180) * COS(dest.lat * pi()/180) *
 POWER(SIN((orig.lon -dest.lon) * pi()/180 / 2), 2) )) AS distance
  FROM zips orig, zips dest
   WHERE orig.zip=center_zip AND
         dest.lon between lon1 and lon2 AND
         dest.lat between lat1 and lat2 
    having distance < dist
     ORDER BY distance;