使用php和md5登录和注册

Question

I'm trying to hash the users password using md5 but I can't log in. It store the password hashed but when I do the login it doesn't work.Why? These are the functions (before I started using md5 it worked)

function checkLogin($username, $password)
{
    $password=md5($password);
    $checkLogin = "select * from users where username='$username' AND password='$password'";
    $check = mysql_query($checkLogin);
    return mysql_num_rows($check) > 0 ? true : false;
}

function setRegistration($username, $password) {
    $query = "insert into users (username, password) values('$username' , md5('$password'))";

    mysql_query($query)
    or die (mysql_error());
}

Answer 1

I found the mistake.

1. Column password was varchar(10) instead of varchar(32) (thank you for telling me that!)
2. When I was trying to resolve the problem I wrote that :

$check = $Database->checkLogin($_POST['username'], md5($_POST['password']));

and then in the database function

function checkLogin($username, $password)
    {
        $password=md5($password);
        $checkLogin = "select * from users where username='$username' AND password='$password'";
        $check = mysql_query($checkLogin);
        return mysql_num_rows($check) > 0 ? true : false;
    }

So I was basically doing an hash of a already hashed password!