Mysql Latitude Longitude distance

distance.sql

SELECT
  id,
  (3959 * acos(cos(radians(:latitude)) * cos(radians(lat)) * cos(radians(lng) - radians(:longitude)) +
               sin(radians(:latitude)) * sin(radians(lat)))) AS distance
FROM user
HAVING distance < :distance
ORDER BY distance
LIMIT 0, 20;