Select coordinates which fall within a radius of a central point?

Question

I have a database of coordinates in the schema:

ID:Latitude:Longitude:name:desc

I\'ve set up my google maps application to show the markers effectively on the sc

Answer 1

The SQL below should work:

SELECT * FROM Table1 a 
WHERE (
          acos(sin(a.Latitude * 0.0175) * sin(YOUR_LATITUDE_X * 0.0175) 
               + cos(a.Latitude * 0.0175) * cos(YOUR_LATITUDE_X * 0.0175) *    
                 cos((YOUR_LONGITUDE_Y * 0.0175) - (a.Longitude * 0.0175))
              ) * 3959 <= YOUR_RADIUS_INMILES
      )

This is based on the spherical law of cosines, for more detailed information on the topic, check out this article - http://www.movable-type.co.uk/scripts/latlong.html