题解 | 获取指定客户每月的消费额
获取指定客户每月的消费额
https://www.nowcoder.com/practice/ed04f148b63e469e8f62e051d06a46f5
select
date_format(t.t_time,'%Y-%m') as time,
sum(case when t.t_type = 1 then t.t_amount else 0 end ) as total
from trade t
inner join customer c
on c.c_id = t.t_cus
where year(t.t_time) = 2023 and c.c_name = 'Tom'
group by time
order by time asc
按照计算出来的time字段来分组，该字段就是2023＋月份的形式
