题解 | 电商平台需要对商品的销售和评价情况进行综合分析

SELECT product_id,product_name,total_quantity,average_rating
FROM products_underline 
JOIN (
	SELECT product_id, ROUND(AVG(rating),2) AS average_rating
	FROM reviews_underline 
	GROUP BY product_id
	HAVING AVG(rating) <4) a
USING(product_id)
JOIN 
    (SELECT product_id, SUM(quantity) AS total_quantity
    FROM sales_underline
    GROUP BY product_id)b 
USING(product_id)
ORDER BY average_rating, product_id