select curdate();B. curtime:当前时间
select curtime();C. now:当前日期和时间
select now();D. YEAR , MONTH , DAY:当前年、月、日
select YEAR(now()); select MONTH(now()); select DAY(now());E. date_add:增加指定的时间间隔
select date_add(now(), INTERVAL 70 YEAR );F. datediff:获取两个日期相差的天数
select datediff('2023-04-01', '2023-12-01');案例:
select name, datediff(curdate(), entrydate) as 'entrydays' from emp order by entrydays desc;