[RESOLVED] User exists not working properly

Dvdbrink

In my registration file I use thos code to check if the username is already taken:

$checkuser = mysql_query("SELECT username FROM users WHERE username='".$_POST['username']."' ");
$user_exist = mysql_num_rows($checkuser);
if($user_exist > 0)
{
	echo "<font color=\"#FF0000\"><b>The Username you specified has already been taken.</b></font><br />";
	exit();
}

The error pops up as it should be when theres another error, no password filled in for example. However when the only error is that the username is already in use the code ignores it and registers.
Any ideas what I can do to fix it?

halojoy

$sql = "SELECT * FROM users WHERE username='" . $_POST["username"] . "'";
if(!($result = mysql_query($sql))) {
 		die(mysql_error());
}
if(mysql_num_rows($result) > 0)	{
        echo "<font color=\"#FF0000\"><b>The Username you specified has already been taken.</b></font><br />";
		exit();
}

hi
I can not see anything wrong with your code.
Does this happen every time, only some time and has this been for long?

Logically you should check your query:

tablename
fieldname
values used in query

A good way to avoid this issue completely, is to
CREATE TABLE
with field 'username' set to be UNIQUE KEY
This will make it impossible to add a username,
that is NOT UNIQUE to the already existing.

Dvdbrink

I made the code yesterday, and its been like this ever since then. Its always happening when its the only error.
I used your code and I'm still having the same problem.
Yes, I could make username unique, but that way it will still say that the registration is succesfull, but just won't add it in the table.
I've no idea on how to fix this. >.<

laserlight

Its always happening when its the only error.

That's because your code logic is incorrect. You should place that unique username handling code in the same block as the code that inserts into the database, not in the block that handles missing user input.

Incidentally, you should check that incoming variables exist with [man]isset[/man] or [man]empty[/man] before using them.

Dvdbrink

Thanks laserlight I got it working now.

Btw how can I make the thread resolved? I can't find those thread tools.

laserlight

Thanks laserlight I got it working now.

You're welcome 🙂

Btw how can I make the thread resolved? I can't find those thread tools.

In a menu bar towards the top of this page, above your first post in this thread, you will find a "View First Unread" link. On its right is the "Thread Tools" link.