select t1.user_id, t1.date as first_buy_date, t2.date as second_buy_date, t3.cnt from (select user_id, min(date) as date from order_info where product_name in ('C++','Java','Python') and date > '2025-10-15' and status = 'completed' group by user_id) t1 join (select user_id, date from (select user...