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 
    o.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 o
join customer_info c on o.order_id =c.order_id
where order_date between '2024-01-01' and '2024-06-30'
group by 1
order by 1;