Calculating Distances from Latitude and Longitude

In this scenario, you're looking to determine the points within a 15-mile radius of the user-entered coordinates. To achieve this, you can leverage mathematical formulas to calculate distances.

Consider the following PHP function:

function get_distance($latitude1, $longitude1, $latitude2, $longitude2, $unit = 'Mi') { 

    // Calculate the angle difference
    $theta = $longitude1 - $longitude2; 

    // Calculate the distance
    $distance = (sin(deg2rad($latitude1)) * sin(deg2rad($latitude2)))   
                (cos(deg2rad($latitude1)) * cos(deg2rad($latitude2)) * 
                cos(deg2rad($theta))); 

    // Convert to degrees
    $distance = acos($distance); 
    $distance = rad2deg($distance); 

    // Convert to miles or kilometers
    $distance = $distance * 60 * 1.1515; 

    // Round the distance
    return (round($distance,2));
}

Alternatively, you can utilize a database query to accomplish this:

$query = "SELECT *,(((acos(sin((".$latitude."*pi()/180)) * 
            sin((`Latitude`*pi()/180)) cos((".$latitude."*pi()/180)) * 
            cos((`Latitude`*pi()/180)) * cos(((".$longitude."- `Longitude`)* 
            pi()/180))))*180/pi())*60*1.1515
        ) as distance 
        FROM `MyTable` 
        HAVING distance > ".$distance.";