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Calculate Distance between 2 Geo Locations in PHP MySQL
Geolocation serves in a multitude of contexts. In this internet era, everything is on the single palm. Various technology uses various methods to get geolocations and distance between two locations.
We are going to use PHP MySQL as technology to calculate the distance between two geo coordinates.
We are going to use PHP MySQL as technology to calculate the distance between two geo coordinates.
So, I have a table
geo_cord
containing two fields latitude
and longitude
and I need to calculate the user input distance
in km with another user inputs user_latitude
and user_longitude
. Well! we need to write a query:
We need to find all results from Database within user input distance
$distance = 50; // user input distance
$user_latitude = '26.826999'; // user input latitude
$user_longitude = '-158.265114'; // user input logtitude
$sql = "SELECT ROUND(6371 * acos (cos ( radians($user_latitude) ) * cos( radians( latitude ) ) * cos( radians( longitude ) - radians($user_longitude) ) + sin ( radians($user_latitude) ) * sin( radians( latitude ) ))) AS distance,geo_cord.* FROM geo_cord HAVING distance <= $distance";
There are other methods to achieve the same result, but I prefer this simple method with less coding and quick result.
I have found a formula in Wikipedia Haversine formula which determines the great-circle distance between two points on a sphere given their longitudes and latitudes.
So it also gives result:
function distance($latitude1, $longitude1, $latitude2, $longitude2) {
$pi80 = M_PI / 180;
$lat1 *= $pi80;
$lon1 *= $pi80;
$lat2 *= $pi80;
$lon2 *= $pi80;
$r = 6372.797; // radius of Earth in km 6371
$dlat = $lat2 - $lat1;
$dlon = $lon2 - $lon1;
$a = sin($dlat / 2) * sin($dlat / 2) + cos($lat1) * cos($lat2) * sin($dlon / 2) * sin($dlon / 2);
$c = 2 * atan2(sqrt($a), sqrt(1 - $a));
$km = $r * $c;
return round($km);
}
There are simple methods to achieve complex challenges. We just need to convert all challenges into opportunities. 😋
NOTE: NOTE: The map image is only for example purpose. It is not actual output.
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