题解 | #获取指定客户每月的消费额#

select
    date_format (t.t_time,"%Y-%m") as time,
    sum(t.t_amount) as total
from
    trade t,
    customer c
where
    t.t_cus = c.c_id
    and c.c_name = 'Tom'
    and year(t.t_time) = 2023
    and t.t_type = 1
group by 
    date_format (t.t_time,"%Y-%m")
order by
    date_format (t.t_time, "%Y-%m")