题解 | 对商品的销售情况进行深度分析

select product_category,age_group,total_sales_amount,round(total_sales_amount/sum(total_sales_amount) over(partition by product_category),2) as purchase_percentage from(
SELECT
	category AS product_category,
	age_group,
	sum(quantity * price) AS total_sales_amount
FROM
	products p
	LEFT JOIN sales s ON p.product_id = s.product_id
	LEFT JOIN customer_info c ON s.sale_id = c.sale_id 
GROUP BY
	1,
	2 
ORDER BY
	1) t group by 1,2