CODEWITHSUNDEEP
phpmysqlajaxgoogle-maps
lnelson92
lnelson92

Reputation: 621

Radius Search PHP, MYSQL and Google Maps

Im searching a database with the latitude and longitude of a location. I want to retrieve all of the locations within a certain radius.

I then encode the returned results into a JSON and retrieve the data using ajax, however I get an undefined error meaning that there is no data returned from the database.

Can anybody see where im going wrong?

Heres my query

$sql="SELECT *, ACOS( SIN( RADIANS( `lat` ) ) * SIN( RADIANS( $fLat ) ) + COS( RADIANS( `lat` ) )
* COS( RADIANS( $fLat )) * COS( RADIANS( `lng` ) - RADIANS( $fLon )) ) * 6380 AS `distance`
FROM `markers`
WHERE ACOS( SIN( RADIANS( `lat` ) ) * SIN( RADIANS( $fLat ) ) + COS( RADIANS( `lat` ) )
    * COS( RADIANS( $fLat )) * COS( RADIANS( `lng` ) - RADIANS( $fLon )) ) * 6380 < 10
    ORDER BY `distance`";


    $result = mysql_query($sql);

    while($r = mysql_fetch_assoc($result)) $rows[] = $r;

    echo json_encode($rows);

Upvotes: 6

Views: 16065

Answers (2)

Sworup Kumar Swain
Sworup Kumar Swain

Reputation: 41

Try this one:

$sql="SELECT * , ACOS( SIN( RADIANS( 'lat' ) ) * SIN( RADIANS( $fLat ) ) + COS( RADIANS( 'lat' ) ) * COS( RADIANS( $fLat )) * COS( RADIANS( 'lng' ) - RADIANS( $fLon )) ) * 6380 AS distance FROM 'markers'
WHERE  distance < 10
ORDER BY distance";

$result = mysql_query($sql);

$rows = mysql_fetch_assoc($result));

echo json_encode($rows);  `

Upvotes: 1

Heitor Chang
Heitor Chang

Reputation: 6057

I'm not much help with trig or SQL, I've just seen enough Google maps questions to point you to this tutorial:

https://developers.google.com/maps/articles/phpsqlsearch#findnearsql

There is a query for finding spots by distance in a radius that you can try, hope it works for you.

Use 3959 (in miles) or 6371 (in km)

Upvotes: 6

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