mysql---日期函数

1,curdate

mysql> select curdate(); +------------+
| curdate() | +------------+
| 2016-11-21 | +------------+
1 row in set (0.01 sec)

返回当前年月日
2， curtime

mysql> select curtime(); +-----------+
| curtime() | +-----------+
| 15:00:14 | +-----------+
1 row in set (0.00 sec)

返回当前时间
3，now

mysql> select now(); +---------------------+
| now() | +---------------------+
| 2016-11-21 15:00:46 | +---------------------+
1 row in set (0.00 sec)

返回年月日加时间
4, unix_timestamp

mysql> select unix_timestamp(); +------------------+
| unix_timestamp() | +------------------+
| 1479711690 | +------------------+
1 row in set (0.00 sec)

返回当前unix时间戳
5，from_unixtime

mysql> select from_unixtime(unix_timestamp()); +---------------------------------+
| from_unixtime(unix_timestamp()) | +---------------------------------+
| 2016-11-21 15:03:36 | +---------------------------------+
1 row in set (0.00 sec)

返回当前时间对应的日期，和unix_timestamp互逆
6，week, year

mysql> select week(now()), year(now()); +-------------+-------------+
| week(now()) | year(now()) | +-------------+-------------+
| 47 | 2016 | +-------------+-------------+
1 row in set (0.00 sec)

当前一年的47周， 当前2016年
7, hour(), minute()

mysql> select hour(curtime()), minute(curtime()); +-----------------+-------------------+
| hour(curtime()) | minute(curtime()) | +-----------------+-------------------+
| 15 | 8 | +-----------------+-------------------+
1 row in set (0.00 sec)

当前时间的15小时，当前时间的8分钟
8， monthname

mysql> select monthname(now()); +------------------+
| monthname(now()) | +------------------+
| November | +------------------+
1 row in set (0.00 sec)

当前日期的英文月份名称
9 date_format

mysql> select date_format(now(), '%M, %D, %Y'); +----------------------------------+
| date_format(now(), '%M, %D, %Y') | +----------------------------------+
| November, 21st, 2016 | +----------------------------------+
1 row in set (0.00 sec)

按照指定格式输出日期
10，datediff

mysql> select datediff('2010-09-04', now()); +-------------------------------+
| datediff('2010-09-04', now()) | +-------------------------------+
| -2270 | +-------------------------------+
1 row in set (0.00 sec)

返回2个时间相差天数