Views and relationship

I need help on a [module]_views.inc declaration...

First, the summary :

I have three tables : nodes, content_watcho_picture and watcho_picture.

- picture table is a content-type table with following informations : nid, wpid (same as nid), fid, owner.
- content_watcho_picture is a "related" table, which store relations between a node (ie: an album) and one or multiple watcho_picture node(s). fields are following :
-- nid : master node id
-- wpid : watcho_picture nid
-- delta : weight of the picture in the master node (to order pictures)

node.nid => content_watcho_picture.nid
content_watcho_picture.wpid => watcho_picture.nid (or wpid, twice are same).

My goal is the following : I want to create a view with nid argument (an album nid) and get all watcho_pictures attached to this album. BUT, because there is a "but"... But I would like to specify for example : use ajax : TRUE, use pager : TRUE, items to display : 12.
Actually, I can retrieve all pictures from a specific node, but there is no page, because the pager is specified on the album nid... There is only one album, also the pager isn't displayed...

I have tried many different combination in my [module]_views.inc but don't get the correct way to retrieve all pictures and get a pager for the next pictures displayed...

This is my actual hook_views_data declaration :

function watcho_picture_views_data() {
  // Basic table information.

  // ----------------------------------------------------------------

  $data['watcho_picture']['table']['group'] = t('Picture');
  $data['watcho_picture']['table']['base'] = array(
    'field' => 'nid',
    'title' => t('Picture'),
    'help' => t('Picture uploaded by uploadify field'),
  );
  
  $data['watcho_picture']['table']['join'] = array(
    'node' => array(
      'left_table' => 'content_watcho_picture',
      'left_field' => 'nid',
      'field' => 'nid',
      'type' => 'INNER',
    ),
    'content_watcho_picture' => array(
      'left_field' => 'wpid',
      'field' => 'wpid',
    ),
  );
  
  $data['watcho_picture']['wpid'] = array(
    'title' => t('wpid'),
    'help' => t('The id of the picture.'),

    'field' => array(
      'handler' => 'views_handler_field_numeric',
      'click sortable' => TRUE,
     ),
    'filter' => array(
      'handler' => 'views_handler_filter_numeric',
    ),
    'sort' => array(
      'handler' => 'views_handler_sort',
    ),
  );
  $data['watcho_picture']['fid'] = array(
    'title' => t('file id'),
    'help' => t('The file id of the picture.'),

    'field' => array(
      'handler' => 'views_handler_field_numeric',
      'click sortable' => TRUE,
     ),
    'filter' => array(
      'handler' => 'views_handler_filter_numeric',
    ),
    'sort' => array(
      'handler' => 'views_handler_sort',
    ),
  );



  
  $data['content_watcho_picture']['table']['group'] = t( 'Picture');
  $data['content_watcho_picture']['table']['join'] = array(
    'watcho_picture' => array(
      'left_field' => 'wpid',
      'field' => 'wpid',
    ),
    'node' => array(
      'left_field' => 'nid',
      'field' => 'nid',
      'type' => 'INNER',
    ),
  );

  $data['content_watcho_picture']['wpid'] = array(
    'title' => t('Picture'),
    'help' => t('Get all pictures node related with the current node.'),
    'relationship' => array(
      'handler' => 'views_handler_relationship',
      'base' => 'watcho_picture',
      'base field' => 'wpid',
      'label' => t('watcho picture'),
    ),
  );

  $data['content_watcho_picture']['picture'] = array(
    'title' => t('Picture'),
    'help' => t('The picture itself.'),
    'field' => array(
      'handler' => 'views_handler_field_picture',
    ),
  );
  $data['content_watcho_picture']['delta'] = array(
    'title' => t('Delta'),
    'help' => t('The delta of picture.'),
    'sort' => array(
      'handler' => 'views_handler_sort',
    ),
  );
  
  return $data;
}

And the query executed is the following :

SELECT node.nid AS nid, 
watcho_picture_content_watcho_picture__content_watcho_picture.wpid AS watcho_picture_content_watcho_picture__content_watcho_picture_wpid, 
watcho_picture_content_watcho_picture__content_watcho_picture.delta AS watcho_picture_content_watcho_picture__content_watcho_picture_delta 
FROM node node  
INNER JOIN content_watcho_picture content_watcho_picture 
ON node.nid = content_watcho_picture.nid 
LEFT JOIN watcho_picture watcho_picture_content_watcho_picture 
ON content_watcho_picture.wpid = watcho_picture_content_watcho_picture.wpid 
LEFT JOIN content_watcho_picture watcho_picture_content_watcho_picture__content_watcho_picture 
ON watcho_picture_content_watcho_picture.wpid = watcho_picture_content_watcho_picture__content_watcho_picture.wpid 
WHERE (node.nid = 118947 ) 
ORDER BY watcho_picture_content_watcho_picture__content_watcho_picture_delta ASC

I think I'm near a solution, but I don't find the good way to achieve my declaration and get the pager working correctly...

Please, any help would be really appreciated.

Thanks in advance for your suggestions and remarks.