select o.id,o.is_group_buy,
        case when o.is_group_buy="Yes" then NULL else c.name end as client_name 
from order_info o
left join client c
on o.client_id=c.id
where o.date>"2025-10-15"
and o.product_name in("C++","Java","Python")
and o.status="completed"
/*选择符合条件的user_id*/
and o.user_id in (select user_id from
            (select id,user_id,row_number() over (partition by user_id order by id) as rr
             from order_info
             where product_name in("C++","Java","Python")
             and status="completed")r
             where r.rr>=2)
order by o.id