具体参考这个链接 http://www.arubin.org/files/geo_search.pdf

完整sql公式:
SELECT *, 3956 * 2 * ASIN(SQRT(
POWER(SIN((@orig_lat - abs(dest.lat)) * pi()/180 / 2), 2) + COS(@orig_lat * pi()/180 ) * COS(abs(dest.lat) * pi()/180) * POWER(SIN((@orig_lon - dest.lon) *
pi()/180 / 2), 2) )) as distance FROM hotels dest
having distance < @dist ORDER BY distance limit 10\G;

快速公式
SELECT destination.*,
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 hotels dest ORDER BY Distance limit 10;