PDO returning incorrect, but duplicate, data. Key's not in database.

I'm new to using $pdo statements so might be something simple I haven't yet read on php.net. I'm receiving duplicate results when querying the database.

Result:

[0] => Array
    (
        [umeta_id] => 31
        [0] => 31
        [user_id] => 2
        [1] => 2
        [meta_key] => fbmeta
        [2] => fbmeta
        [meta_value] => someMetaValueStuff;
        [3] => someMetaValueStuff;
    )

The query is quite simple:

function getData(){
    global $pdo;
    $query = $pdo->prepare('SELECT * FROM usermeta WHERE meta_key = "fbmeta" LIMIT 0,30');
    $query->execute();

    return $query->fetchAll();
}

print_r( getData() );

The problem is that the named keys (umeta_id, user_id, meta_key, meta_value) DO exist, the numeric keys do not. How come the query returns these? And how do I prevent them from even being returned?

It's not duplicates, it's just the current FETCH_MODE you're using. To get as associative keys only you need to specify as such; by default it fetches as both.

Use like so:

$query->fetchAll(PDO::FETCH_NUM); // to fetch with numeric indexes
$query->fetchAll(PDO::FETCH_ASSOC); // to fetch with associative indexes

fetchAll docs
fetch docs

This is not duplicate data fetchAll returns data in numeric array as well as associative array.

See the Docs

Use this for retrieving only associative array

return $query->fetchAll(PDO::FETCH_ASSOC);