题解 | 每个顾客最近一次下单的订单信息

select
    t.order_id,
    c.customer_name,
    t.order_date
from
    (select
        customer_id,
        order_id,
        order_date,
        row_number() over(partition by customer_id order by order_date desc) as r_rank
    from
        orders) t
left join 
    customers c on t.customer_id = c.customer_id
where 
    t.r_rank = 1