题解 | 每个顾客最近一次下单的订单信息

with
    last_time as (
        select
            customer_id,
            max(order_date) as max_date
        from
            orders
        group by
            customer_id
    )
select
    o.order_id,
    c.customer_name,
    l.max_date as order_date
from
    orders o
    inner join last_time l on o.order_date = l.max_date
    and o.customer_id = l.customer_id
    inner join customers c on o.customer_id = c.customer_id
order by
    c.customer_name