题解 | #牛客的课程订单分析(二)#

# 需要把握哪些条件可以在where条件就被筛选去除
select user_id
from order_info
where datediff(`date`, '2025-10-15') > 0
group by user_id
having sum(if(status = 'completed' and product_name in ('C++', 'Java', 'Python'), 1, 0)) > 1
order by user_id;