题解 | #某店铺的各商品毛利率及店铺整体毛利率#

SELECT 
    '店铺汇总' AS product_id,
    CONCAT(ROUND((1 - SUM(in_price*cnt) / SUM(price*cnt))*100, 1), '%') AS profit_rate
FROM tb_order_detail t3
JOIN tb_order_overall t2 ON t3.order_id = t2.order_id
JOIN tb_product_info t1 ON t3.product_id = t1.product_id
WHERE shop_id = 901 AND event_time > '2021-10-01'

UNION 

SELECT
    t3.product_id,
    CONCAT(ROUND((1 - SUM(in_price*cnt) / SUM(price*cnt))*100, 1), '%') AS profit_rate
FROM tb_order_detail t3
JOIN tb_order_overall t2 ON t3.order_id = t2.order_id
JOIN tb_product_info t1 ON t3.product_id = t1.product_id
WHERE shop_id = 901 AND event_time > '2021-10-01'
GROUP BY product_id
HAVING ROUND((1 - SUM(in_price*cnt) / SUM(price*cnt))*100, 1) > 24.9

分别查询得到店铺汇总的毛利率和各商品的毛利率，再使用UNION函数将其合并。