select
    SUBSTRING(t_time, 1, 7) as time,
    sum(t_amount) as total
from
    trade
    join customer on trade.t_cus = customer.c_id
where
    c_name = 'Tom' and SUBSTRING(t_time, 1, 4) = 2023 and t_type = 1 
group by
    time
order by
    time