Geolocalization for WordPress queries

wordpress_geo_searchs.sql

CREATE PROCEDURE geodist (IN mylat decimal(18,12), IN mylon decimal(18,12), IN dist float)
BEGIN
declare lon1 float;
declare lon2 float;
declare lat1 float;
declare lat2 float;
set lon1 = mylon-dist/abs(cos(radians(mylat))*69);
set lon2 = mylon+dist/abs(cos(radians(mylat))*69);
set lat1 = mylat-(dist/69);
set lat2 = mylat+(dist/69);
SELECT p.*, 
  3956 * 2 * ASIN(SQRT( POWER(SIN((mylat -lat.meta_value) * pi()/180 / 2), 2) +COS(mylat * pi()/180) * COS(lat.meta_value * pi()/180) *POWER(SIN((mylon - lon.meta_value) * pi()/180 / 2), 2) )) as distance 
FROM wp_posts as p, 
  wp_postmeta lat, 
  wp_postmeta lon 
WHERE p.ID = lat.post_id 
  and lat.meta_key = 'latitude' 
  and p.ID = lon.post_id 
  and lon.meta_key = 'longitude' 
  and lon.meta_value between lon1 and lon2 
  and lat.meta_value between lat1 and lat2
  and post_status = 'publish'
having distance < dist 
ORDER BY Distance;
END