"Call to undefined method" on class property!?

[Allen McCabe <allenmccabe@xxxxxxxxx>]

I have a singleton database object in a global file at the top of my
document. In most other locations I am able to access it just fine, however
in my footer I want to loop through a properties list for links (I am saving
links to a database, each with its own properties).

Here is the code snippet that is giving me trouble:

footerlinks.inc.php:

<?php
        $result = $db->query('SELECT * FROM `links` WHERE `category` =
\'footer_navigation\';');
        $total = $db->affected_rows;

        if ($total > 0)
        {
            $Link = new Link();
            $count = $db->affected_rows($result);
            $i = 0;
            while ($row = $db->fetch_array($result))
            {
                $properties = $Link->setLinkProperties($row);

                $link[$i] = '<a ';
                foreach ($properties as $prop)
                {
                    $link[$i] .= $prop;
                }
                $link[$i] .= '>';
                $row['text'];
                $link[$i] .= '</a>';

                $i++;
            }

            $j = 0;
            while ($j < $link)
            {
                echo $link[$j];
                if ($j < $count)
                {
                    echo ' | ';
                }

                $j++;
            }

        }

    ?>

The $Link->$Link->setLinkProperties() method is defined in

Link.class.php:

<?php

class Link {

    public function setLinkProperties($rows)
    {
        if (!empty($row['href']))
        {
            $properties['href'] = 'href="' . $row['href'] . '" ';
        }

        if (!empty($row['class']))
        {
            $properties['class'] = 'class="' . $row['class'] . '" ';
        }

        if (!empty($row['style']))
        {
            $properties['style'] = 'style="' . $row['style'] . '" ';
        }

        if (!empty($row['title']))
        {
            $properties['title'] = 'title="' . $row['title'] . '" ';
        }

        if (!empty($row['name']))
        {
            $properties['name'] = 'name="' . $row['name'] . '" ';
        }

        if (!empty($row['target']))
        {
            $properties['target'] = 'target="' . $row['target'] . '" ';
        }

        if (!empty($row['rel']))
        {
            $properties['rel'] = 'rel="' . $row['rel'] . '" ';
        }

        if (!empty($row['onclick']))
        {
            $properties['onclick'] = 'onclick="' . $row['onclick'] . '" ';
        }

        if (!empty($row['ondblclick']))
        {
            $properties['ondblclick'] = 'ondblclick="' . $row['ondblclick']
. '" ';
        }

        if (!empty($row['onmouseover']))
        {
            $properties['onmouseover'] = 'onmouseover="' .
$row['onmouseover'] . '" ';
        }

        if (!empty($row['onmouseout']))
        {
            $properties['onmouseout'] = 'onmouseout="' . $row['onmouseout']
. '" ';
        }

        return $properties;

    } // END OF METHOD setLinkProperties
} // END OF CLASS

?>

Also for reference, the method query() in my database class sets a value for
$affected_rows:

Database.class.php:

<?php

class Database {

    private $server   = ''; //database server
    private $user     = ''; //database login name
    private $pass     = ''; //database login password
    private $database = ''; //database name
    private $pre      = ''; //table prefix

    #######################
    //internal info
    private $error = '';
    private $errno = 0;

    //number of rows affected by SQL query
    public $affected_rows = 0;

...

?>

This is the error I am receiving:

"*Fatal error*: Call to undefined method Database::affected_rows() in *
/home/mwclans1/public_html/components/footerlinks.inc.php* on line *9*"

Please help PHP gurus!!