题解 | #获取指定客户每月的消费额#

select
    date_format (t_time, "%Y-%m") as `time`,
    sum(`t_amount`) as `total`
from trade
join customer
on trade.t_cus = customer.c_id
where year(t_time) = 2023 and t_type = 1 and c_name = 'Tom'
group by
    date_format (t_time, "%Y-%m")
order by
    date_format (t_time, "%Y-%m");