Question

I have table with places and each have lat and lon points
I have lat lon point and wanted distance in KM,
I need to find matching rows in db for this distance with select command

is there any way to do it, witout selecting all rows and run function for each point to calcultae the distance?

thanks

Answer 1

thanks all!
here is the answer:

    String SelectString = "SELECT * FROM (SELECT *,(((acos(sin((";
    SelectString += userLat;
    SelectString += "*pi()/180)) * sin((latPoint*pi()/180))+cos((";
    SelectString += userLat;
    SelectString += "*pi()/180)) * cos((latPoint*pi()/180)) * cos(((";
    SelectString += userLon;
    SelectString += "- lonPoint)*pi()/180))))*180/pi())*60*1.1515*1.609344) as distance FROM MYTABLE ) t WHERE distance <=";
    SelectString += userDistance;