    static function lookupByUsername($username) {
        if (strpos($username, '@') !== false)
            $user = static::lookup(array('user__emails__address'=>$username));
        else
            $user = static::lookup(array('username'=>$username));

        return $user;
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.