WP_Query in a Service Class

I have been experimenting with the following standard codex query and loop:

define('WP_USE_THEMES', false);
require('../../wp/wp-blog-header.php');
....
<?php $my_query = new WP_Query("showposts=1&post_type=page&page_id=4");
	while ($my_query->have_posts()) : $my_query->the_post();
		 $do_not_duplicate = $post->ID; ?>
			<p>
			      <?php the_content(); ?>
			</p>
	<?php endwhile; ?>

I have a PHP service where I would like to implement this in a class. e.g.:

<?php
define('WP_USE_THEMES', false);
require_once '../../wp/wp-blog-header.php';

class CMSService {
	public function getPage() {
		$my_query = new WP_Query("showposts=1&post_type=page&page_id=4");
                while ($my_query->have_posts()) {
                     $my_query->the_post();
                     $do_not_duplicate = $post->ID;
                     the_content();
               }
	}
}
?>

I’m not sure of the return type yet, perhaps json_encode, perhaps htmlentities..that is rather trivial as the JQuery request will decode JSON or HTML or whatever I send back.

The main issue here is that I am receiving a 500 ‘Database Error: Error establishing a database connection’ in the POST request result. Note that in a standard HTML template in the same directory using the loop style from first example does not error. Any ideas or examples you might be able to share?
Thanks in advance!