select rownum,nt_date,case when dd=7 then '星期六' else '星期日' 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
时间格式转换
select to_char(sysdate,‘yyyy-mm-dd hh24:mi:ss’) as nowTime from dual; //日期转化为字符串
select to_char(sysdate,‘yyyy’) as nowYear from dual; //获取时间的年
select to_char(sysdate,‘mm’) as nowMonth from dual; //获取时间的月
select to_char(sysdate,‘dd’) as nowDay from dual; //获取时间的日
select to_char(sysdate,‘hh24’) as nowHour from dual; //获取时间的时
select to_char(sysdate,‘mi’) as nowMinute from dual; //获取时间的分
select to_char(sysdate,‘ss’) as nowSecond from dual; //获取时间的秒