题解 | #牛客的课程订单分析(七)#

select ifnull(d.name, 'GroupBuy') as source, c.cnt
from (
    select client_id, count(id) as cnt from order_info
    where user_id in (
        select user_id from order_info
        where status = 'completed' and date > '2025-10-15'
        and product_name in ('C++', 'Python', 'Java')
        group by user_id
        having count(id) > 1
    )
    and status = 'completed' and date > '2025-10-15'
    and product_name in ('C++', 'Python', 'Java')
    group by client_id
) c
left join client d
on c.client_id = d.id
order by source