--
-- file_storage__get_parent_id/1
--
create or replace function file_storage__get_parent_id(
  integer
) returns int4 as $$
 -- cr_items.item_id%TYPE
     declare 
         get_parent_id__item_id alias for $1;
         v_parent_id          cr_items.item_id%TYPE;
     begin

         select parent_id
         into v_parent_id
         from cr_items
         where item_id = get_parent_id__item_id;

       return v_parent_id;

end;$$ language plpgsql;