题解 | 查询出每个品牌在不同月份的总销售额以及购买该品牌商品的用户的平均年龄

select
    category_id,
    sum(order_amount) as total_sales,
    sum(if(customer_gender = '男', 1, 0)) as male_customers,
    sum(if(customer_gender = '女', 1, 0)) as female_customers
from
    order_details
    left join customer_info using (order_id)
where
     order_date between '2024-01-01' and '2024-06-30'
group by
    category_id
order by category_id