Spatial query in sql database - spatial-query

Question

hi I am currently developing a geo location based app which updates the user's location and displays the shops around him, I am using ordinary sql queries in sql database .My php code to select the shops around the user is :
/*
* Following code will list all the products
*/
// array for JSON response
$response = array();
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
if (isset($_POST['code']) && isset($_POST['lat']) && isset($_POST['lng'])) {
$code = $_POST['code'];
$lng = $_POST['lng'];
$lat = $_POST['lat'];
// get all data from table this is my code to fetch data where i need change
$result = mysql_query("SELECT *, ( 3959 * acos( cos( radians($lat) ) * cos( radians( lat ) ) * cos( radians(lng) - radians($lng) ) + sin( radians($lat) ) * sin( radians(lat)))) AS distance
FROM maintable
HAVING distance < 25
ORDER BY distance
") or die(mysql_error());
// check for empty result
if (mysql_num_rows($result) > 0) {
// looping through all results
// products node
$response["people"] = array();
while ($row = mysql_fetch_array($result)) {
// temp user array
$people = array();
$product["_id"] = $row["_id"];
$product["name"] = $row["name"];
$product["distance"] = $row["distance"];
$product["lat"] = $row["lat"];
$product["lng"] = $row["lng"];
$product["image_bit"] = $row["image_bit"];
$product["security"] = $row["security"];
$product["status"] = $row["status"];
$product["code"] = $row["country_code"];
$product["phone"] = $row["phone"];
// push single product into final response array
array_push($response["people"], $people);
}
// success
$response["success"] = 1;
// echoing JSON response
echo json_encode($response);
} else {
// no products found
$response["success"] = 0;
$response["message"] = "No people found";
// echo no users JSON
echo json_encode($response);
}
}
else{
//required field is missing
$response["success"] = 0;
$response["message"] = "Required field missing";
// echoing JSON response
echo json_encode($response);
}
?>
i store the user's latitude and longitude values as lat and lng respectively.
But i recently heard about spatial datatype in sql,which will is more efficient, what i need to know is if i need to use spatial queries what change should be done in my lat and lng columns in sql table and can please anyone modify mysql query as a spatial query .any help would be appreciable

Answer 1

You can try a quadkey. Translate the points to a binary and interleave it. Treat it as base-4 number. The quadkey is similar to a quadtree but also it has interesting properties. It is often use for tiling.