select
t1.pay_method,
count(*) as cnt
from
(select 
case when u.pay_method<>'' then u.pay_method else 'error' end as pay_method
from user_client_log u left join product_info p
on u.product_id=p.product_id
where p.product_name='anta' and step='select') t1
group by t1.pay_method
order by cnt desc