1.oracle查询周六周日的日期

select rownum,nt_date,case when dd=7 then '星期日' else '星期六' end holiddate from(

 select to_date('2021-01-01','yyyy-mm-dd')+rownum nt_date,to_char(to_date('2021-01-01','yyyy-mm-dd')+rownum,'D') dd from dual

connect by to_char(to_date('2021-01-01','yyyy-mm-dd')+rownum,'YYYY')='2021'

) where dd=1 or dd=7