[PHP] Can't find error

[NSA]

For some reason PHP is throwing this error at me:

Notice​

: Undefined variable: rank in ​

C:\xampp\htdocs\main\user_bar.html​

on line ​

18​

Here is my code (I hope you can find the error because I sure as hell can't!):​

$q = mysql_query("SELECT * FROM users WHERE username = '$username'");
while($row = mysql_fetch_assoc($q)){
$rank = $row['rank'];
echo $rank;
}
?>
<div id="top_bar">
Welcome back, <?php echo $_SESSION['myusername'] . "  ";?><br />
| <a href="logout.php">Logout</a>
<?php
if($rank == "admin"){
echo " | <a href=\"add_post.php\">Create Blog Post</a> | ";
}else{
 
}
?>
<a href="messages.php">Messages</a> |
</div>

 

[tyr0ne]

try to echo your $row variable first. can always use print_r for more info (echo will only ouput Array())

from there well it depends on what is printed.

 

[Ecko]

What happens when you change

if($rank == "admin"){

To

if($row['rank'] == "admin"){

 

[NSA]

Neither echo or print_r produces any result while used inside the while.

----------- EDIT -----------

So I logged out of the account with user status, logged into an account with admin status then re-logged into the account with user status and it fixed it.

Would it have been something to do with my session maybe?

 

[IntactDev]

Neither echo or print_r produces any result while used inside the while.

----------- EDIT -----------

So I logged out of the account with user status, logged into an account with admin status then re-logged into the account with user status and it fixed it.

Would it have been something to do with my session maybe?

That, or $rank wasn't defined anywhere.

 

[Weasel]

I think your errors are on developer mode. You can use this to prevent errors like that:

error_reporting(E_ALL ^ E_NOTICE);

Or add:

$rank = '';

This errors are saying that the $rank var isn't set, untill the rows are requested from the database (so aren't set). This isn't anything that you should prevent because its a security risk, but some coders like to do stuff like that.