mysql常用日期时间/数值函数(二)
mysql> select weekday(now());
+----------------+
| weekday(now()) |
+----------------+
| 3 |
+----------------+
1 row in set (0.00 sec)
返回表达式是一年的第几周
mysql> select week(now());
+-------------+
| week(now()) |
+-------------+
| 19 |
+-------------+
1 row in set (0.00 sec)
WEEK()允许指定星期是否开始于星期天或星期一。如果第二个参数是0，星期从星期天开始，如果第二个参数是1， 从星期一开始，如下所示：
mysql> select week(now(),0);
+---------------+
| week(now(),0) |
+---------------+
| 19 |
+---------------+
1 row in set (0.00 sec)
mysql> select week(now(),1);
+---------------+
| week(now(),1) |
+---------------+
| 20 |
+---------------+
1 row in set (0.00 sec)
返回表达式一年中季度
mysql> select quarter(now());
+----------------+
| quarter(now()) |
+----------------+
| 2 |
+----------------+
1 row in set (0.00 sec)
返回表达式一周的第一天
mysql> select dayofweek(now());
+------------------+
| dayofweek(now()) |
+------------------+
| 5 |
+------------------+
1 row in set (0.00 sec)
返回表达式一个月的第几天
mysql> select dayofmonth(now());
+-------------------+
| dayofmonth(now()) |
+-------------------+
| 16 |
+-------------------+
1 row in set (0.00 sec)
返回表达式一年的第几天
mysql> select dayofyear(now());
+------------------+
| dayofyear(now()) |
+------------------+
| 136 |
+------------------+
1 row in set (0.00 sec)
返回表达式的星期名字
mysql> select dayname(now());
+----------------+
| dayname(now()) |
+----------------+
| Thursday |
+----------------+
1 row in set (0.00 sec)
mysql> select monthname(now());
+------------------+
| monthname(now()) |
+------------------+
| May |
+------------------+
1 row in set (0.00 sec)
mysql>
提取表达式的年份
mysql> select year(now());
+-------------+
| year(now()) |
+-------------+
| 2013 |
+-------------+
1 row in set (0.00 sec)
提取表达式的月份
mysql> select month(now());
+--------------+
| month(now()) |
+--------------+
| 5 |
+--------------+
1 row in set (0.01 sec)
提取表达式的天数
mysql> select day(now());
+------------+
| day(now()) |
+------------+
| 16 |
+------------+
1 row in set (0.00 sec)
提取表达式的小时
mysql> select hour(now());
+-------------+
| hour(now()) |
+-------------+
| 16 |
+-------------+
1 row in set (0.00 sec)
提取表达式的分钟
mysql> select minute(now());
+---------------+
| minute(now()) |
+---------------+
| 31 |
+---------------+
1 row in set (0.00 sec)
提取表达式的秒数
mysql> select second(now());
+---------------+
| second(now()) |
+---------------+
| 34 |
+---------------+
1 row in set (0.00 sec)
将当前日期按照'YYYY-MM-DD' 或YYYYMMDD 格式的值返回，具体格式根据函数用在字符串或是数字语境中而定。
mysql> select curdate();
+------------+
| curdate() |
+------------+
| 2013-05-16 |
+------------+
1 row in set (0.00 sec)
mysql> select curdate()+1;
+-------------+
| curdate()+1 |
+-------------+
| 20130517 |
+-------------+
1 row in set (0.00 sec)
将当前时间以'HH:MM:SS'或 HHMMSS的格式返回，具体格式根据函数用在字符串或是数字语境中而定。
mysql> sel