题解 | 每个商品的销售总额

select 
    name as product_name,
    sum(quantity) as total_sales
    ,row_number()over(partition by category order by sum(quantity) desc) as category_rank
from orders o
left join products p 
on o.product_id=p.product_id
where name is not null
group by category,name
order by category,total_sales desc

其实如果不运行一遍我根本不知道还需要加where name is not null。