1. 计算季度的天数
select
trunc(ref_date,'Q') q_date -- 季度第一天
,max(ref_date) max_date -- 季度最后一天（若没过完，就取截止到今天的天数）
,(datediff(max(ref_date),trunc(ref_date,'Q'))+1) sum_day --季度天数
from tableA
group by trunc(ref_date,'Q')
2.计算最近3天数据（动态）
select
ref_date -- 日期
,amount -- 金额
,sum(amount) over(order by ref_date rows between 2 preceding and current row) amount_3 -- 当前行到前移2行之和
,sum(amount) over(order by ref_date rows between 2 preceding and 2 following) amount_33 --当前行前后各移2行之和
,sum(amount) over(order by ref_date rows between unbounded preceding and unbounded following) amount_all --从第一行累加到最后一行
from tableA
group by ref_date,amount
