MySQL中adddate学习

-- 修改时间：ADDDATE(date,INTERVAL expr unit)
-- 含义：date时间，expr 表达式值，unit表达式对应的时间单位
-- unit :  SECOND,MINUTE,HOUR,DAY,MONTH,YEAR
SELECT ADDDATE(NOW(),INTERVAL -60 SECOND)
SELECT ADDDATE(NOW(),INTERVAL -1 MINUTE)
SELECT ADDDATE(NOW(),INTERVAL -1 HOUR)
SELECT ADDDATE(NOW(),INTERVAL -1 DAY)
SELECT ADDDATE(NOW(),INTERVAL -1 MONTH)
SELECT ADDDATE(NOW(),INTERVAL -1 YEAR)