CREATE OR REPLACE FUNCTION cursor_demo()    RETURNS refcursor AS  $BODY$  DECLARE cur CURSOR FOR select id , totalspace from aaa where discardflag = '0';	v_id int;	v_totalspace int;begin  open cur;  FETCH  cur into v_id,v_totalspace ;  while found loop    insert into a values (v_id,v_totalspace);	  FETCH next from  cur into v_id,v_totalspace ;  end loop;  RETURN cur ;  close cur;END;$BODY$    LANGUAGE plpgsql;