Multiple MySQL Inputs - php

Question

I have a script which looks like this which retrieves song information that people are scrobbling on LastFM:
class NowPlaying{
private $url;
private $noTrackPlayingMessage;
function __construct($user, $api_key){
// construct URL
$this->url = 'http://ws.audioscrobbler.com/2.0/?method=user.getrecenttracks&limit=1';
$this->url .= '&user=' . $user . '&api_key=' . $api_key;
// default message
$this->noTrackPlayingMessage = 'Nothing is playing right now!';
}
// return the artist and track currently playing
public function getNowPlaying(){
// create an XML object
$xml = simplexml_load_file($this->url);
// get the latest track
$track = $xml->recenttracks->track;
// check if the track is actually playing
$nowplaying = $track->attributes()->nowplaying;
// return the track and artist if music is playing, otherwise show message
if($nowplaying){
$artist = $track->artist;
$songname = $track->name;
return $artist . ' - ' . $songname;
}
else{
return $this->noTrackPlayingMessage;
}
}
// set the message to be shown when no music is playing
public function setNoTrackPlayingMessage($messageIn){
$this->noTrackPlayingMessage = $messageIn;
}
} // end class
$nowPlaying = new NowPlaying($id, 'APIGOESHERE');
$nowPlaying->setNoTrackPlayingMessage($id); // optional
$currentplaying = $nowPlaying->getNowPlaying();
While this is useful for just an individual LastFM account however I want to run several accounts through this script which the details are stored in a MySQL database. My table has two columns, lastfmusername and currentsong. I want to find get all the songs those lastfm user's are listening to and then store them in their currentsong field.
I've tried adding the following to the top:
$sql = "SELECT lastfmusername FROM data";
$id = $db->query($sql);
Then the following to the bottom:
$sql2 = "UPDATE lastfmtable SET currentsong = '$currentplaying' WHERE lastfmusername = '$id'";
$cursong = $db->query($sql2);
But that failed so I'm not sure how to approach this. Any help would be appreciated.

Answer 1

$sql = "SELECT lastfmusername FROM data";
will return an array containing ALL values of lastfmusername, not just one.
Try this instead:
$sql = "SELECT lastfmusername FROM data";
$users = $db->query($sql);
$id = $users[0]['lastfmusername'];
meaning: $id will now store the first result.
You'll need to loop through the result of users and run the update query for each user. So what you are trying to do should look like this:
foreach($users as $r){
$id= $r['lastfmusername'];
$nowPlaying = new NowPlaying($id, 'APIGOESHERE');
$nowPlaying->setNoTrackPlayingMessage($id); // optional
$currentplaying = $nowPlaying->getNowPlaying();
$sql2 = "UPDATE lastfmtable SET currentsong = '$currentplaying' WHERE lastfmusername = '$id'";
$cursong = $db->query($sql2);
}