select now() 当前时间;
![](https://images2015.cnblogs.com/blog/1073330/201612/1073330-20161201172045459-2001189602.png)
SELECT curdate() 当天日期;
![](https://images2015.cnblogs.com/blog/1073330/201612/1073330-20161201175635927-1207038461.png)
select date_sub(curdate(),interval 1 day) 前一天日期;
![](https://images2015.cnblogs.com/blog/1073330/201612/1073330-20161201173409662-1269007002.png)
select date_sub(curdate(),interval 1 year) 上一年日期;
![](https://images2015.cnblogs.com/blog/1073330/201612/1073330-20161201173440896-1164636764.png)
select date_sub(curdate(),interval 1 month) 上个月日期;
![](https://images2015.cnblogs.com/blog/1073330/201612/1073330-20161201173524256-1810135292.png)
SELECT YEAR(DATE_SUB(CURDATE(),INTERVAL 0 year)) 当前年份;
SELECT YEAR(DATE_SUB(CURDATE(),INTERVAL 1 year)) 上一年份;
SELECT month(DATE_SUB(CURDATE(),INTERVAL 0 month)) 当前月份;
SELECT month(DATE_SUB(CURDATE(),INTERVAL 1 month)) 上一月份;
SELECT day(DATE_SUB(CURDATE(),INTERVAL 0 DAY)) 当前几号;
SELECT day(DATE_SUB(CURDATE(),INTERVAL 1 DAY)) 前一天几号;