HSQL判断日期是否最后一周

select 
     day
,case 
        when month(day) != month(date_add(day,7)) then 'y' 
        else 'n' 
    end as is_last_week -- 是否月份最后一周
from (
select '2021-06-06' as day union all
select '2021-06-13' as day union all
select '2021-06-20' as day union all
select '2021-06-27' as day union all
select '2021-07-04' as day union all
select '2021-07-11' as day union all
select '2021-07-18' as day union all
select '2021-07-25' as day union all
select '2021-08-01' as day
) t1
;