-- -- photo_album__get_root_folder/1 -- create or replace function photo_album__get_root_folder( integer ) returns int4 as $$ declare v_package_id alias for $1; v_folder_id integer; begin select coalesce(folder_id,0) into v_folder_id from pa_package_root_folder_map where package_id = v_package_id; if v_folder_id > 0 then return v_folder_id; else return null; end if; end; $$ language plpgsql;