Question

I’m using JSON_encode to send data to a js file for tracks. A user could have one or several tracks so that’s where the problem lies. Not sure how to organise my array to allow for several arrays. I can’t use an array within an array since all the JSON data needs to be separated preferably so there will be something like;

track1 {ID:110232....}
track2 {ID:21402....}

What I have now works fine if there is just one track.

$ID = $_GET['ID'];
$result = mysql_query("SELECT * FROM tracks WHERE ID = '$ID' ORDER BY timestamp DESC");
while($row = mysql_fetch_array($result)){
    $T_ID = $row['T_ID'];
    $T_url = $row['url'];
    $T_name = $row['name'];
    $T_timestamp = $row['timestamp'];
    $arr = array('T_ID' => $ID,'T_name' => $T_name, 'T_url' => $T_url, 'T_timestamp' => $T_timestamp );

    echo json_encode($arr);
}

Answer 1

Why can’t you use an (associative) array inside an container array like this:

$cont = array();
while($row = mysql_fetch_array($result)){
  $T_ID = $row['T_ID'];
  $T_url = $row['url'];
  $T_name = $row['name'];
  $T_timestamp = $row['timestamp'];
  $arr = array('T_ID' => $ID,'T_name' => $T_name, 'T_url' => $T_url, 'T_timestamp' => $T_timestamp );

  $cont[] = $arr;
}

echo json_encode($cont);

This results in a JSON structure like this, which keeps all your tracks in separate objects:

[ 
  {'T_ID': 1, 'T_name': 1, ... },
  {'T_ID': 2, 'T_name': 2, ... },
  {'T_ID': 3, 'T_name': 3, ... },
  ...
]

^{As noted in the comments you should switch to PDO or mysqli- functions, but this doesn’t matter for the problem at hand.}.