题解 | 查询出每个品牌在特定时间段内的退货率以及平均客户满意度评分

# 查询每个品牌在 2024 年 7 月的退货率（退货数量/总销售数量）以及平均客户满意度评分。查询出来的数据按照品牌 ID 升序排列。
select a.brand_id,brand_name,
        round(sum(return_status)/count(*),2) as return_rate_July_2024,
        round(avg(customer_satisfaction_score),2) as average_customer_satisfaction_score
from brand_info as a
inner join sales_orders as b
on a.brand_id = b.brand_id
inner join customer_feedback as c
on b.order_id = c.order_id
where date_format(order_date,'%Y%m') = '202407'
group by a.brand_id,brand_name
order by a.brand_id