mysql - 如何将 MySQL 中的毫秒数与给定日期进行比较

Question

使用

mysql  Ver 14.12 Distrib 5.0.45, for redhat-linux-gnu (i686) using readline 5.0

我有一个这样定义的表:

+-----------------------+--------------+------+-----+---------+-------+
| Field                 | Type         | Null | Key | Default | Extra |
+-----------------------+--------------+------+-----+---------+-------+
| id                    | bigint(20)   | NO   | PRI |         |       | 
| user_id               | bigint(20)   | NO   | MUL |         |       | 
| directory_id          | bigint(20)   | NO   | MUL |         |       | 
| attribute_name        | varchar(255) | NO   |     |         |       | 
| attribute_value       | varchar(255) | YES  |     | NULL    |       | 
| attribute_lower_value | varchar(255) | YES  |     | NULL    |       | 
+-----------------------+--------------+------+-----+---------+-------+

为我最后一次验证的时间选择 attribute_value 返回

+-------------------+-----------------+
| attribute_name    | attribute_value |
+-------------------+-----------------+
| lastAuthenticated | 1330380013284   | 
+-------------------+-----------------+

如果我使用 http://www.epochconverter.com/ 验证该值它说

Assuming that this timestamp is in milliseconds:
GMT: Mon, 27 Feb 2012 22:00:13 GMT

但是如果我尝试下面的代码行

mysql> select from_unixtime('1330380013284');
+--------------------------------+
| from_unixtime('1330380013284') |
+--------------------------------+
| NULL                           | 
+--------------------------------+

有谁能立即知道我在这里缺少什么？

Answer 1

您需要除以 1000 并删除引号，否则您的日期会偏离

SELECT FROM_UNIXTIME(theField/1000);

SELECT FROM_UNIXTIME(1330380013284/1000);

请参阅文档 - 注意 MySQL 方法返回 SECONDS，而不是像您使用的那样返回毫秒:

MySQL docs for UNIX_TIMESTAMP

If called with no argument, returns a Unix timestamp 
(SECONDS since '1970-01-01 00:00:00' UTC) as an unsigned integer