Find closest location with longitude and latitude

Question

I am working on a application where I need to get nearby location, my web service will receive 2 parameters (decimal longitude, decimal latitude )

I have a table wh

Answer 1

Here is Solution

var constValue = 57.2957795130823D

var constValue2 = 3958.75586574D;

var searchWithin = 20;

double latitude = ConversionHelper.SafeConvertToDoubleCultureInd(Latitude, 0),
                    longitude = ConversionHelper.SafeConvertToDoubleCultureInd(Longitude, 0);
var loc = (from l in DB.locations
let temp = Math.Sin(Convert.ToDouble(l.Latitude) / constValue) *  Math.Sin(Convert.ToDouble(latitude) / constValue) +
                                 Math.Cos(Convert.ToDouble(l.Latitude) / constValue) *
                                 Math.Cos(Convert.ToDouble(latitude) / constValue) *
                                 Math.Cos((Convert.ToDouble(longitude) / constValue) - (Convert.ToDouble(l.Longitude) / constValue))
                             let calMiles = (constValue2 * Math.Acos(temp > 1 ? 1 : (temp < -1 ? -1 : temp)))
                             where (l.Latitude > 0 && l.Longitude > 0)
                             orderby calMiles

select new location
  {
     Name = l.name
  });
  return loc .ToList();