#使用if、substring、round函数简易实现#

select  product_id, 
        round(sum(if_click)/count(if_click), 3) ctr,
        round(sum(if_cart)/sum(if_click), 3) cart_rate,
        round(sum(if_payment)/sum(if_cart), 3) payment_rate,
        round(sum(if_refund)/sum(if_payment), 3) refund_rate
from tb_user_event
where substring(event_time, 1, 7) = '2021-10'
group by product_id
having refund_rate <= 0.5
order by product_id;