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

with t1 as (select o.order_id,category_id,order_amount,order_date,customer_id,customer_gender,
case 
when customer_gender = '男' then 1
else 0 end as count_male,
case 
when customer_gender = '女' then 1
else 0 end as count_female
 from order_details as o 
join customer_info c 
on c.order_id = o.order_id
where date(order_date) between '2024-01-01'and '2024-06-30')
select category_id,sum(order_amount) as total_sales, sum(count_male) as male_customers, sum(count_female) as female_customers from t1
group by category_id