你可以试试这个SQL。我解释了SQL本身的逻辑-它是一个两步的过程-第一步是计算日期之间的假期，第二步是将它们串联起来。

select startdate , enddate , 
CONCAT_WS(',', collect_list(holidays) holidays -- This will concat holidays for a given start and end dt
from (
select h.holidays holidays,startdate , enddate 
from holidays h
join start_end_dt_table daytab on h.date between startdate and enddate  -- this subqry will give me data between start and end dt
) rs
group by startdate , enddate