declare  
RoomID Room.RoomID%Type;  
RoomName Room.RoomName%Type;  
cursor crRoom is  
select RoomID,RoomName  
from Room;  
   
begin  
open crRoom;loop（这里不要加分号）
fetch crRoom into RoomID,RoomName;  
exit when crRoom%notFound;  
end loop;  
close crRoom;   
end; 

begin
    open rt_cursor for
    select * from dual;    
end;