题解 | 牛客的课程订单分析(四)

select
    t3.user_id,
    min(t3.date) as first_buy_date,
    count(id) as cnt
from
    (select
        t1.*
    from 
        order_info t1
    inner join
        (select user_id
        from order_info
        where 
            status='completed'
            and product_name in('C++','Java','Python')
            and date>'2025-10-15'
        group by user_id
        having count(id)>=2) t2
    on 
        t1.user_id=t2.user_id
    where 
        status='completed'
        and product_name in('C++','Java','Python')
        and date>'2025-10-15')t3
group by t3.user_id
order by t3.user_id