load data from a table using Datatable plugin by converting php array to JSON

http://i172.photobucket.com/albums/w11/urboyfriend/symbols.jpg

<?PHP
        $user_name = "root";   //connect to server
    $password = "";
    $database = "testdb";
    $server = "127.0.0.1";

    $db_handle = mysql_connect($server, $user_name, $password);
    $db_found = mysql_select_db($database, $db_handle);



        $queryString = "SELECT * FROM symbols";  
        $result = mysql_query($queryString);
        $totalRows = mysql_num_rows($result);

        for ($i = 0; $i < $totalRows; ++$i) {

                 $postData[$i] = mysql_fetch_array($result);

            }


        $myJSONString = json_encode($postData);
        echo $myJSONString;




?>

im not sure where to go next