题解 | 每个顾客购买的最新产品名称

select
    customer_id,
    customer_name,
    product_name as latest_order
from
    (select 
        customer_id,customer_name,product_name,
        row_number() over(partition by customer_id
        order by order_date desc)as rk
    from
        (select 
        o.customer_id,customer_name,product_name,order_date
        from orders o 
        join customers c on o.customer_id=c.customer_id
        join products p on o.product_id=p.product_id
        group by 1,2,3,4)t)t1
where rk=1
order by customer_id;