class Serie extends DataObject{

static $db = array ('SerieName' =>'Varchar(20)',
----- and some more --------
);

static $has_one = array(
'SeriePage' =>'SeriePage',
' Cover' => 'Image'
);

static $has_many = array (' SerieSeasons' => 'SerieSeason');

public function getCMSFields()
{
return new FieldSet(
new TextField('SerieName'),
-------And Some more -----,
new ImageUploadField('Cover'),
new DataObjectManager(
$this,
'SerieSeasons',
'SerieSeason',
array('SeasonNmbr' => 'Seizoen')
));

-------------------------------------------------------------------------------------------------

class SerieSeason extends DataObject {

static $db = array('SeasonNmbr' =>' Varchar(20)');

static $has_one = array('Serie' => 'Serie');

static $has_many = array('SerieEpisodes' => 'SerieEpisode');

public function getCMSFields()
{
return new FieldSet
(
new TextField('SeasonNmbr', ' Seizoen' ),
new DataObjectManager(
$this,
' SerieEpisodes',
'SerieEpisode'
);
----------------------------------------------------------------------------------------------------
class SerieEpisode extends DataObject {

static $db = array('EpisodeName' =>' Varchar);

static $has_one = array('SerieSeason' => 'SerieSeason');
----------------------------------------------------------------------------------------------
class SeriePage extends Page {

static $has_many = array ('Series' => ' Serie');

public function getCMSFields()
{
$fields = parent::getCMSFields();
$fields -> addFieldToTab("Root.Content.Series", new DataObjectManager($this));
return $fields;
}