DQL: Retrive the child components in virtual document

If you have the r_object_id of a Virtual Document you always can launch the following DQL:

SELECT r_object_id FROM dm_sysobject 
          IN DOCUMENT ID('virtual_doc_id') DESCEND

But if you don't have the r_object_id and you want to extract the child components with a sigle query you must execute:

SELECT r_object_id,object_name,r_object_type,r_content_size,
  a_content_type,r_is_virtual_doc,r_link_cnt,r_lock_owner,
  a_content_type,owner_name,i_is_reference
 FROM dm_document
 WHERE r_is_virtual_doc <> 1 AND
  i_chronicle_id IN ( 
    SELECT component_id
     FROM dmr_containment
     WHERE parent_id = 'Virtual_Doc_ID'
)

If you want, for example, to retrieve all the child components from a virtual doc associated to a task you could launch the following query:

SELECT r_object_id,object_name,r_object_type,r_content_size,
  a_content_type,r_is_virtual_doc,r_link_cnt,
  r_lock_owner,a_content_type,owner_name,i_is_reference
 FROM dm_document
 WHERE r_is_virtual_doc <> 1 AND
  i_chronicle_id IN ( 
   SELECT component_id
                        FROM dmr_containment
                        WHERE parent_id IN ( 
    SELECT distinct r_component_id
                                 FROM dmi_package
                                 WHERE r_workflow_id IN ( 
           SELECT router_id
                FROM dmi_queue_item  
                WHERE r_object_id='TASK_ID'
                              ) 
   ) 
)