mysql 中 unix_timestamp和from_unixtime 时间戳函数
1.unix_timestamp将时间转化为时间戳。（date 类型数据转换成 timestamp 形式整数）没传时间参数则取当前时间的时间戳mysql> select unix_timestamp();+------------------+
| unix_timestamp() |
+------------------+
| 1361586358 |
+------------------+
1 row in set (0.01 sec)
mysql> select unix_timestamp('2013-01-01 10:10:10');
+---------------------------------------+
| unix_timestamp('2013-01-01 10:10:10') |
+---------------------------------------+
| 1357006210 |
+---------------------------------------+
1 row in set (0.00 sec)
2.from_unixtime将timestamp 形式整数 转化为 date类型
mysql>select from_unixtime(1355272360);
+---------------------------+
| from_unixtime(1355272360) |
+---------------------------+
| 2012-12-12 08:32:40 |
+---------------------------+
1 row in set (0.00 sec)当然也可以指定输出的时间格式：mysql>select from_unixtime(1355272360,'%Y%m%d');
+------------------------------------+
| from_unixtime(1355272360,'%Y%m%d') |
+------------------------------------+
| 20121212 |
+------------------------------------+
3.关于mysql 时间戳的限制目前timestamp 所能表示的范围在 1970-2038之间 。超过这个范围 得到的时间将会溢出 得到的时间是null.mysql>select from_unixtime(0);
+---------------------+
| from_unixtime(0) |
+---------------------+
| 1970-01-01 08:00:00 |
+---------------------+mysql> select from_unixtime(2147483647);
+---------------------------+
| from_unixtime(2147483647) |
+---------------------------+
| 2038-01-19 11:14:07 |
+---------------------------+
1 row in set (0.00 sec)
页:
[1]