Oracle for 循环输出(游标提取)

-- 循环输出用户表信息(游标提取)
declare
  -- 提取游标对象,方便单独维护SQL
  cursor cursor_all_users is
    select user_id, username, created from all_users;
  -- 游标子项(更多的时候,表是动态表,所以这句声明也可以省略)
  -- cursor_user all_users%rowtype;
begin
  for cursor_user in cursor_all_users loop
    dbms_output.put_line(cursor_user.username);
  end loop;
end;