[impala] 01. 현재 날짜 다루기, string to date format

select now() as today_timestamp
      ,to_date(now()) as today_date
      ,from_timestamp(to_date(now()) , 'yyyyMMdd') as dt
      ,from_timestamp(now(), 'yyyyMMdd') as dtt;

 

select dt --'20210531'
      ,from_unixtime(unix_timestamp(dt, 'yyyyMMdd'), 'yyyy-MM-dd') as dt_date -'2021-05-31'