with t1 as
(select a.product_id product_id,product_name,sale_month,quantity
from sales_underline a 
join products_underline b 
on a.product_id = b.product_id
where substring(sale_month,7,1) between 1 and 6)

select product_id,product_name,
sum(quantity) as total_sales,
max(quantity) as max_monthly_sales,
min(quantity) as min_monthly_sales,
round(avg(quantity),0) as avg_monthly_sales
from t1 
group by product_id,product_name
order by product_id