How would I write the equiv. of this query in rails?

Question

I would like to query a table in rails using this query (found here ):

    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

(finds all points located within a certain radius of a given point)

Answer 1

The answer is to use GeoKit-Rails (or GeoKit-Rails3 ). Then your queries will look like this:

Store.find(:all, :origin => @somewhere, :within=>10)

or the Rails3 version:

Location.within(5, :origin => @somewhere)

where @somewhere is a point ( [37.792,-122.393] ), zip, address, etc.