MySQL에서 current_time/current_date()와 now()의 차이점은 무엇입니까

current_date()는 현재 시간의 날짜만 표시합니다

例如：
select current_date() from a ;
结果：2021-08-25

current_time()은 현재 시간의 시, 분, 초만 표시합니다

例如：
select CURRENT_TIME() from a ;
14:07:06

now()는 모두 표시

例如：
select now() from a ;
结果：2021-08-25 14:07:56

날짜를 늘리거나 줄일 때 current_time , current_date()는 now()와 유사합니다. 차이점은 다음과 같습니다. CURRENT_DATE() function

#获取当前日期
SELECT CURRENT_DATE() AS newDate;    #2021-05-20
#当前日期加1天（其他天数方法一样）
SELECT DATE_ADD(CURRENT_DATE(), INTERVAL 1 DAY) AS newDate;    #2021-05-21
#当前日期减1天
SELECT DATE_ADD(CURRENT_DATE(), INTERVAL -1 DAY) AS newDate;   #2021-05-19
#当前日期加1个月
SELECT DATE_ADD(CURRENT_DATE(), INTERVAL 1 MONTH) AS newDate;  #2021-06-20
#当前日期减1个月
SELECT DATE_ADD(CURRENT_DATE(), INTERVAL -1 MONTH) AS newDate; #2021-04-20
#当前日期加1年
SELECT DATE_ADD(CURRENT_DATE(), INTERVAL 1 YEAR) AS newDate;   #2022-05-20
#当前日期减1年
SELECT DATE_ADD(CURRENT_DATE(), INTERVAL -1 YEAR) AS newDate;  #2020-05-20

#指定日期加1天（可将DAY换为MONTH,YEAR来实现加1个月,1年）
SELECT DATE_ADD('2021-05-20', INTERVAL 1 DAY) AS newDate;    #2021-05-21
#指定日期减1天（可将DAY换为MONTH,YEAR来实现减1个月,1年）
SELECT DATE_ADD('2021-05-20', INTERVAL -1 DAY) AS newDate;   #2021-05-19

#当前时间添加1小时10分钟10秒钟
SELECT DATE_ADD(NOW(), INTERVAL '1:10:10' HOUR_SECOND) AS newTime;    #2021-05-20 15:59:32
#指定时间添加1小时10分钟10秒钟
SELECT DATE_ADD('2019-04-17 2:00:00', INTERVAL '1:10:10' HOUR_SECOND) AS newTime;    #2021-04-17 03:10:10

NOW() function

#获取当前时间
SELECT NOW() AS newTime;    #2021-05-20 14:28:41
#当前时间减30秒
SELECT (NOW() - INTERVAL 30 SECOND) AS newTime;    #2021-05-20 14:29:31
#当前时间加30秒
SELECT (NOW() + INTERVAL 30 SECOND) AS newTime;    #2021-05-20 14:29:31
#当前时间减30分钟
SELECT (NOW() - INTERVAL 30 MINUTE) AS newTime;    #2021-05-20 14:02:26
#当前时间加30分钟
SELECT (NOW() + INTERVAL 30 MINUTE) AS newTime;    #2021-05-20 15:02:41
#当前时间减1天
SELECT (NOW() - INTERVAL 1 DAY) AS newTime;        #2021-05-19 14:33:26
#当前时间加1天
SELECT (NOW() + INTERVAL 1 DAY) AS newTime;        #2021-05-21 14:33:33
#当前时间减1个月
SELECT (NOW() - INTERVAL 1 MONTH) AS newTime;      #2021-04-20 14:34:10
#当前时间加1个月
SELECT (NOW() + INTERVAL 1 MONTH) AS newTime;      #2021-06-20 14:34:47
#当前时间减1年
SELECT (NOW() - INTERVAL 1 YEAR) AS newTime;       #2020-05-20 14:35:09
#当前时间加1年
SELECT (NOW() + INTERVAL 1 MONTH) AS newTime;      #2022-05-20 14:35:23

#指定时间的加减，将上面的NOW()函数换为指定日期时间即可，以加30分钟为例，如下:
SELECT ('2021-05-20 12:30:00' + INTERVAL 30 MINUTE) AS newTime;        #2021-05-20 13:00:00

위 내용은 MySQL에서 current_time/current_date()와 now()의 차이점은 무엇입니까의 상세 내용입니다. 자세한 내용은 PHP 중국어 웹사이트의 기타 관련 기사를 참조하세요!