我想使用此查询(在此处找到)查询 rails 中的表:
Select ID, Postcode, Lat, Lon,
acos(sin($lat)*sin(radians(Lat)) + cos($lat)*cos(radians(Lat))*cos(radians(Lon)-$lon))*$R As D
From MyTable
Where acos(sin($lat)*sin(radians(Lat)) + cos($lat)*cos(radians(Lat))*cos(radians(Lon)-$lon))*$R < $rad
(查找位于给定点一定半径内的所有点)