题解 | 对商品的销售情况进行深度分析

select
    category as product_category,
    age_group,
    total_sales_amount,
    round(
        total_sales_amount / sum(total_sales_amount) over (
            partition by
                category
        ),
        2
    ) as purchase_percentage
from
    (
        select
            category,
            age_group,
            sum(quantity * price) as total_sales_amount
        from
            sales as s
            inner join customer_info as c on s.sale_id = c.sale_id
            inner join products as p on p.product_id = s.product_id
        group by
            category,
            age_group
    ) as scp
order by
    product_category,
    purchase_percentage desc;

用表链接加窗口函数解决