Mysql select where and order by - php

Question

i got a point system that are like people can upgrade to [PRO1] user. everyones rights(pro1,pro2,user) are stored in my mysql users table. But i want to make a little feed, that shows the latest one that upgraded to [PRO1]. the upgrade code:
$insert = "UPDATE `users` SET `points` = (`points`-50) WHERE `username` = '".$username."' and points > 50";
mysql_query($insert);
if (mysql_affected_rows() > 0)
{
// other codes
$insert = "UPDATE users SET rights=' [PRO1]' WHERE `username` = '".$username."'";
mysql_query($insert);
header('location: succesupgrade.php');
}else{
echo "You don't have enough points";
}
?>
the upgrade code works fine(just incase i need to add a time/date. and tha code for where i want the"'username' wast the last to upgrade to [PRO1]" is in this code:
<?php
require("dbc.php");
$query = mysql_query("select * from users WHERE rights='[PRO1]' order by right DESC limit 1") or die(mysql_error());
while($array = mysql_fetch_array($query)) {
echo "{$array['username']}<br>";
}
?>was the last to upgrade to:
<?php
require("dbc.php");
$query = mysql_query("select * from users WHERE rights='[PRO1]' order by rights DESC limit 1") or die(mysql_error());
while($array = mysql_fetch_array($query)) {
echo "{$array['rights']}<br>";
}
?>
But that code gives me this error:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DESC limit 1' at line 1

Answer 1

order by right must be order by rights in the first query of the second code block.

Answer 2

That query is going to do nothing to tell you who the last user to upgrade to rights='[PRO1]'. That is just a string field. You would need some sort of datetime/timestamp field that is updated when the users rights change, by which you can make the sort.
You also don't need to do 2 queries. You have two queries doing the exact same thing.
Just do:
SELECT username FROM users WHERE rights='[PRO1]' ORDER BY update_timestamp DESC LIMIT 1
Where update_timestamp would be the field that is updated when the rights change.

Answer 3

The reason is because right is a used keyword, you need a back stroke to solve this :;
Like :
select * from `users` WHERE rights='[PRO1]' order by `rights` DESC limit 1