Calculating distance between 2 points with sql

I have to calculate the distance between 2 points, X and Y being the coordinates of the first point while axisX and axisY are the coordinates of the second point. My only lead is this SQL statement, however this开发者_StackOverflow中文版 SQL does not return the result I'm looking for. So can anyone help me identify any mistake I may have made with this statement?

string x = "SELECT TownName,Address,SUBSTRING(X, 1, 2) AS Xaxis, SUBSTRING(Y, 1, 2) AS Yaxis,Type,Availability,Price,Size,Bedrooms,Bathrooms,Contact,Screenshot1,Screenshot2,Screenshot3,Screenshot4 FROM House"+
                                    "WHERE (SQRT(POWER(X - "+axisX+" , 2) + POWER(Y - "+axisY+", 2)) <= 2000)";

SELECT <replace with your select>,

3963.0 * ACOS (
    sin(SUBSTRING(X, 1, 2)/57.2958) * sin(" + axisX + "/57.2958) + cos(SUBSTRING(X, 1, 2)/57.2958) * cos(" + axisX + "/57.2958) * cos(" + axisY + "/57.2958 - SUBSTRING(Y, 1, 2)/57.2958))
as distance
 FROM House
ORDER BY distance

I'm assuming axisX and axisY are your co-ordinates. This uses the distance calculation technique which may provide you a more accurate reading.

http://www.meridianworlddata.com/Distance-Calculation.asp

Hope this helps.