Allowing users to bump an input they submitted every hour?

Question

So, I want people to be able to "bump" what they've wrote in my database but at the same time only allow the input to be in the table ONCE at a time.

For Example:

Jim's code is 5555. Jim enters his code and it shoots to the very bottom of the table. After 34 minutes he tries to enter his code in again (Because various other people have inputted their code between now and then) but gets a display error letting him know he has 26 minutes to wait still.

Joe inputs his code and waits an hour and five minutes and is able to push his code back to the bottom again.

Basically, I'm displaying data from the bottom up in my table.

Is there any way to easily do this? Thanks.

function some_more_custom_content() {

    $output="<BR>";

    ob_start();

    if ($_REQUEST['code'] != "") {
        $code = $_REQUEST['code'];
        $query="INSERT INTO `fc` (`code`,`datetime`) values ('" . mysql_real_escape_string($code) . "', now())";
        $result=mysql_query($query);
        $entry['datetime'] = strtotime($entry['datetime']);

        while ($fetch_array = mysql_fetch_array($result)) {
            $seconds = time() - strtotime($fetch_array["datetime"]);

            if ((time() - $entry['datetime']) < 60*60) {
                echo ("The code " . htmlentities($code) ." was updated less than an hour ago.");
            } else {
                echo ("Inserted " . htmlentities($code) ." into the top.");
            }
        }
?>

I get a syntax error. ANy idea where it is?

UPDATE: Getting error of : Parse error: syntax error, unexpected $end

Answer 1

Not that hard:

Use a timestamp for the last "bump time".

When a code is entered, check if it already exists in the database.
If it doesn't, insert it and set the bump timestamp to now().
If it does exist, check if the timestamp was within the hour. If it was, display error.
If it wasn't, reset it to now().

Sort your display data by bump timestamp.

EDIT:

$entry = /* get entry from database, assuming the case where it already exists */;

// depending on the format of timestamp you get from the database,
// you may have to convert it to a UNIX timestamp:
$entry['timestamp'] = strtotime($entry['timestamp']);

if ((time() - $entry['timestamp']) < 60*60) { // 60*60 is one hour in seconds
    // display error
} else {
    // reset bump
}

Answer 2

you should create a table with a unique index on the code field and then use a query like:

INSERT INTO CODES (code) 
  VALUES (555)
  ON DUPLICATE KEY UPDATE lastUpdated = 
               case when NOW() - INTERVAL 5 MINUTE > lastUpdated 
                  then NOW() 
                  else lastUpdated end

this will update the lastUpdated field only in cases when it's older than 5 minutes