MySQL Great Circle Distance (Haversine formula)

Question

I\'ve got a working PHP script that gets Longitude and Latitude values and then inputs them into a MySQL query. I\'d like to make it solely MySQL. Here\'s my current PHP Cod

Answer 1

I thought my javascript implementation would be a good reference to:

/*
 * Check to see if the second coord is within the precision ( meters )
 * of the first coord and return accordingly
 */
function checkWithinBound(coord_one, coord_two, precision) {
    var distance = 3959000 * Math.acos( 
        Math.cos( degree_to_radian( coord_two.lat ) ) * 
        Math.cos( degree_to_radian( coord_one.lat ) ) * 
        Math.cos( 
            degree_to_radian( coord_one.lng ) - degree_to_radian( coord_two.lng ) 
        ) +
        Math.sin( degree_to_radian( coord_two.lat ) ) * 
        Math.sin( degree_to_radian( coord_one.lat ) ) 
    );
    return distance <= precision;
}

/**
 * Get radian from given degree
 */
function degree_to_radian(degree) {
    return degree * (Math.PI / 180);
}