题解 | 每个顾客购买的最新产品名称

select customer_id, customer_name, product_name latest_order
from(
select o.customer_id, customer_name, product_name
, rank () over(partition by o.customer_id order by order_date desc ) rk
from orders o 
left join customers c on o.customer_id = c.customer_id
left join products p on o.product_id = p.product_id)r
where rk = 1