MySQL - Find points within radius from database - mysql

Question

I have a table which has a POINT column containing the latitude and longitude of various locations.
I then also have a users location from geo-location in the browser.
What I need to be able to do is find all records from the table where the POINT value in the is within a 10 km radius (or X km radius), ordered by distance with the closest first.
My table has a SPATIAL index on the POINT column.

Answer 1

I'm currently working on a project where I'm calculating distances between multiple locations. I'm using the following query for selecting object_id's which are within a given radius.
SELECT id,
( 6371 *
ACOS(
COS( RADIANS( db_latitude ) ) *
COS( RADIANS( $user_latitude ) ) *
COS( RADIANS( $user_longitude ) -
RADIANS( db_longitude ) ) +
SIN( RADIANS( db_latitude ) ) *
SIN( RADIANS( $user_latitude) )
)
)
AS distance FROM the_table HAVING distance <= $the_radius ORDER BY distance ASC"
I can't explain the ACOS formula itself because I got it from research.
db_latitude = database latitude field
db_longitude = database longitude field
$user_latitude = browser latitude coördinate
$user_longitude = browser longitude coördinate
$the_radius = the radius that you want to search in
This is in kilometers.

Answer 2

The query below actually worked for me :
$query = "SELECT *,
( 6371 *
acos(
cos( radians( ".$user_lat." ) ) *
cos( radians( lat ) ) *
cos( radians( lng ) -
radians( ".$user_lng." ) ) +
sin( radians( ".$user_lat." ) ) *
sin( radians( lat ) ) ) )
AS distance FROM parkings
HAVING distance <= ".$radius." ORDER BY distance ASC";
$stmt = $conn->execute($query);
$rows = $stmt->fetchAll('assoc');
where:
$user_lat and $user_lng is browser's lat and lng,
$radius = 10,
table name is parkings

Answer 3

May be this help for you,
https://ru.scribd.com/presentation/2569355/Geo-Distance-Search-with-MySQL
For Django I use this
dist = 20 #дистанция 20 км
mylon = 51.5289156201 # долгота центра
mylat = 46.0209384922 # широта
lon1 = mylon-dist/abs(math.cos(math.radians(mylat))*111.0) # 1 градус широты = 111 км
lon2 = mylon+dist/abs(math.cos(math.radians(mylat))*111.0)
lat1 = mylat-(dist/111.0)
lat2 = mylat+(dist/111.0)
profiles = UserProfile.objects.filter(lat__range=(lat1, lat2)).filter(lon__range=(lon1, lon2))
It search all users in squar 20km.