Lets say i'm listing musical artists, each artist has basic information like Name, Age etc. stored in an artist table. They also have entries in an Albums table (album name/album cover etc), referencing the artist table using the artist id as a foreign key.

I have the Model_Artist (Artist.php) file:

class Model_Artist extends Zend_Db_Table_Abstract
{
    protected $_name = 'artist';
    protected $_dependentTables = array('Model_ArtistAlbums');
    public function fetchArtistss()
    {
        $select = $this->select();
        return $this->fetchAll($select);
    }
}

and to the Model_ArtistAlbums (ArtistAlbums.php) file

class Model_ArtistAlbums extends Zend_Db_Table_Abstract
{
    protected $_name = 'albums';

    protected $_referenceMap = array(
        'Artists' => array(
            'columns'       => 'alb_art_id',
            'refTableClass' => 'Model_Artist',
            'refColumns'    => 'art_id'
        )
    );
    // etc
}

in my controller:

public function indexAction()
{
    /* THIS WORKS
    $art = new Model_Artist();
    $artRowset = $art->find(1);
    $art1 = $artRowset->current();
    $artalbums = $art1->findDependentRowset('Model_ArtistAlbums');
    foreach($artalbums as $album){
        echo $album->alb_title."<br>";
    }
    */
    $arts = new Model_Artist();
    $this->view->artists = $arts->fetchArtists();
}

in the view file:

$this->partial()->setObjectKey('artist');
echo $this->partialLoop('admin/list-artists.phtml', $this->artists);

but with this code in artists/list-artists.phtml:

foreach($this->artist->findDependentRowset('albums') as $album):
// other stuff
endforeach;

i get this error:

Fatal error: Call to a member function findDependentRowset() on a non-object

A var_dump of $this->artist = NULL.