Algorithm to find all Latitude Longitude locations within a certain distance from a given Lat Lng location

Question

Given a database of places with Latitude + Longitude locations, such as 40.8120390, -73.4889650, how would I find all locations within a given distance of a specific locatio

Answer 1

Based on the current user's latitude, longitude and the distance you wants to find,the sql query is given below.

SELECT * FROM(
    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*1.609344) as distance FROM Distances) t
WHERE distance <= @distance

@latitude and @longitude are the latitude and longitude of the point. Latitude and longitude are the columns of distances table. Value of pi is 22/7

Answer 2

You may find these questions helpful:

• Formulas to Calculate Geo Proximity
• Maximum length of a decimal latitude/longitude Degree?

Answer 3

What you need is spatial search. You can use Solr Spatial search. It also got lat/long datatype built in, check here.

Answer 4

You may convert latitude-longitude to UTM format which is metric format that may help you to calculate distances. Then you can easily decide if point falls into specific location.

Answer 5

Thanks to the solution provided by @yogihosting I was able to achieve similar result from schemaless columns of mysql with codes shown below:

// @params - will be bound to named query parameters
$criteria = [];
$criteria['latitude'] = '9.0285183';
$criteria['longitude'] = '7.4869546';
$criteria['distance'] = 500;
$criteria['skill'] = 'software developer';

// Get doctrine connection 
$conn = $this->getEntityManager()->getConnection();

        $sql = '
               SELECT DISTINCT m.uuid AS phone, (((acos(sin((:latitude*pi()/180)) * sin((JSON_EXTRACT(m.location, "$.latitude")*pi()/180))+cos((:latitude*pi()/180)) * 
              cos((JSON_EXTRACT(m.location, "$.latitude")*pi()/180)) * 
              cos(((:longitude - JSON_EXTRACT(m.location, "$.longitude"))*pi()/180))))*180/pi())*60*1.1515*1.609344) AS distance FROM member_profile AS m 
               INNER JOIN member_card_subscription mcs ON mcs.primary_identity = m.uuid
               WHERE mcs.end > now() AND JSON_SEARCH(m.skill_logic, "one", :skill) IS NOT NULL  AND (((acos(sin((:latitude*pi()/180)) * sin((JSON_EXTRACT(m.location, "$.latitude")*pi()/180))+cos((:latitude*pi()/180)) * 
              cos((JSON_EXTRACT(m.location, "$.latitude")*pi()/180)) * 
              cos(((:longitude - JSON_EXTRACT(m.location, "$.longitude"))*pi()/180))))*180/pi())*60*1.1515*1.609344) <= :distance ORDER BY distance
               ';
        $stmt = $conn->prepare($sql);
        $stmt->execute(['latitude'=>$criteria['latitude'], 'longitude'=>$criteria['longitude'], 'skill'=>$criteria['skill'], 'distance'=>$criteria['distance']]);
        var_dump($stmt->fetchAll());

Please note the above code snippet is using doctrine DB connection and PHP