select count(bookmark_id) as n_existing from bm_bookmarks where bookmark_id = :bookmark_id select count(*) from bm_bookmarks where owner_id = :viewed_user_id and parent_id = :parent_id and folder_p = 't' and local_title = :local_title select bookmark_id from bm_bookmarks where folder_p = 't' and owner_id = :user_id and local_title = :local_title select url_id from bm_urls where complete_url = :complete_url select count(bookmark_id) from bm_bookmarks where url_id = :url_id and owner_id = :viewed_user_id and parent_id = :parent_id select count(bookmark_id) from bm_bookmarks where bookmark_id = :bookmark_id