您需要在同一个窗口中运行两个独立的函数，分别用于起始日期和状态：

SELECT distinct order_id,
                first(start_date) over (partition by order_id order by start_date
                                        rows between unbounded preceding and unbounded following) as start_date,
                last(status) over (partition by order_id order by start_date
                                   rows between unbounded preceding and unbounded following) as status
           FROM a_table;