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I'm going through a vid tutorial on creating a user reg & login form in php and mysql.

The following script should echo 'exists' on the login.php form, however just shows a blank (indicating the user does not exist, when it does and s in fact the only username on the DB)

<?php
    function user_exists($username) {
   $username = sanitize($username);
   $query = mysql_query("SELECT * FROM `users` WHERE `username` = '$username'"); 
   return (mysql_result($query, 0) == 1) ? true : false;
 }
?>

The login form portion of code goes as follows:

if (user_exists('andy') === true) {
echo 'exists';
}
die();

Am I missing some syntax or something obvious?? here is a link to the vid tutorial if it helps http://www.youtube.com/watch?v=Til3oVNlho4

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What's your OS? Your BLANK screen - does it have any message on it? Perhaps you don't have a database connection open. Is there any other code on your page? – itsols 20 mins ago
2  
That serie of tutorials contains a lot of bad practice: from using deprecated functions like mysql_query to vulnerable concepts by using md5 for password hashing, and a lot more. If you want to do it right, then I recommend to read a good book. – HamZa 19 mins ago
What happens if you run the query by itself in a mysql tool instead of on the web with php? – Paul 19 mins ago
2  
Please, don't use mysql_* functions in new code. They are no longer maintained and are officially deprecated. See the warning? Learn about prepared statements instead, and use PDO or MySQLi - this article will help you decide which. If you choose PDO, here is a good tutorial. – tereško 16 mins ago
@tereško Funny you should say that. The link for the tutorial you provided the OP is also mysql_, and not mysqli, so why keep the OP on the same track? ;) – Fred 13 mins ago
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1 Answer

up vote -1 down vote

Why not do like this?

<?php
function user_exists($username) {
$username = sanitize($username);
$query = mysql_query("SELECT * FROM `users` WHERE `username` = '$username'"); 
$exists = mysql_num_rows($query) == 1 ? 1 :0;

return $exists; 
}
?>
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