SELECT 
    T3.id,
   T3.is_group_buy,
   CASE WHEN T3.is_g+
        id,
        is_group_buy,client_id,
        COUNT(*) OVER (PARTITION BY user_id) AS t2
    FROM order_info 
    WHERE status = 'completed' 
      AND product_name IN ('C++', 'Java', 'Python') 
      AND date > '2025-10-15' 
) AS T3 
left JOIN client c ON T3.client_id = c.id
WHERE T3.t2 >= 2 
ORDER BY T3.id;