select product_id,
round(sum(if_click)/count(*),3) as ctr,
round(sum(if_cart)/sum(if_click),3) as cart_rate,
round(sum(if_payment)/sum(if_cart),3) as payment_rate,
round(sum(if_refund)/sum(if_payment),3) as refund_rate
from tb_user_event
where date_format(event_time,'%Y%m')='202110'
group by product_id
having refund_rate <=0.5
order by product_id