题解 | 对商品的销售情况进行深度分析

select
    category as product_category,
    age_group,
    sum(quantity * price) as total_sales_amount,
  round(sum(quantity * price)/sum(sum(quantity * price)) over(partition by category ) ,2)  as purchase_percentage
from
    sales
    join products using (product_id)
    join customer_info using (sale_id)
group by
    category,age_group
    order by category asc,purchase_percentage desc