[PHP] Checking for username existance?

[Trigs]

What is the best way to check to see if a username exists?

I use:

$user_check = mysql_query("SELECT username FROM users WHERE username='$r_username'"); 
$do_user_check = mysql_num_rows($user_check); 
 
if($do_user_check > 0) { 
 die('Your username is already in use. Please go <a href="register.php">back</a> and fix it.'); 
} 

But it always returns the "Your username is already in use" error.

[hamheyelliot]

I've absolutely no clue, but if the number on the 3rd line of that code is '0', doesn't that mean that if there are no instances of the username, it will give the error you specified?

But when push comes to shove, I truly have no idea.

[Source]

$userQ = mysql_query("SELECT * FROM `users` WHERE `username`= '$r_username'"); 
$userC = mysql_num_rows($userQ); 
 
if( $userC = 1 ) { 
     die('Your username is already in use. Please go <a href="register.php">back</a> and fix it.'); 
} 

[scottish]

$find_user = mysql_query("SELECT username FROM users WHERE username='$r_username'");
if(mysql_num_rows($find_user)) 
 { 
 die('Your username is already in use. Please go <a href="register.php">back</a> and fix it.'); 
 }

[Source]

Entrance that won't work ...feel free to correct me if i'm wrong... but it would always die on that message because using an if statement like that basically means:

if the mysql_num_rows function works and returns true then do this:

and not

if the username exists in the database then do this.

Sorry if I am incorrect

[Blinger1]

And with yours i would do a double = mark, so it will be

$userQ = mysql_query("SELECT * FROM `users` WHERE `username`= '$r_username'"); 
$userC = mysql_num_rows($userQ); 
 
if( $userC == 1 ) { 
     die('Your username is already in use. Please go <a href="register.php">back</a> and fix it.'); 
} 

[scottish]

mm i've hardly done PHP but i removed the $r_username bit and replaced it with a random one and searched a db i created when it was on it it gave the message and when it didn't showed clear page (obviously as no other code was on it)...

[Calgon]

$find_user = mysql_query( "SELECT * FROM `players` WHERE `name` = '$bonkers'" );

if( mysql_num_rows( $find_user ) == 1 )
{
    echo "Foo' - that username is taken.";
} 

[Source]

Yes blinger I believe that would be correct, my appologies I kind of rushed the response as no-one was really helping.

Oh and calon, thanks for the wonderful block on msn considering how much I helped you. Your welcome.

[Blinger1]

haha no problems