Question

我有一个mysql查询，它从数据库中提取创建和修改时间，然后将它们更改为unix时间

SELECT
    tn,
    title,
    UNIX_TIMESTAMP(create_time) AS create_time,
    UNIX_TIMESTAMP(change_time) AS change_time
FROM
    ticket
WHERE
    responsible_user_id = 2
AND ticket_state_id IN (2, 3, 10)
ORDER BY
    change_time DESC

结果如下：

+---------+----------------------+-------------+-------------+
| tn      | title                | create_time | change_time |
+---------+----------------------+-------------+-------------+
| 7409025 | Re: otrs             |  1459861204 |  1459861263 |
| 7408967 | RINAS@cartrack.co.za |  1459765215 |  1459836797 |
| 7408935 | FW: Vod              |  1459767210 |  1459836797 |

如何从create_time行中减去change_time行，以便行在名为ave的新行中显示结果。

+---------+----------------------+-------------+-------------+------+
| tn      | title                | create_time | change_time | ave  |
+---------+----------------------+-------------+-------------+------+
| 7409025 | Re: otrs             |  1459861204 |  1459861263 |  59  |
| 7408967 | RINAS@cartrack.co.za |  1459765215 |  1459836797 | 71582|
| 7408935 | FW: Vod              |  1459767210 |  1459836797 | 69587|

Answer 1

UNIX_TIMESTAMP(change_time) - UNIX_TIMESTAMP(create_time) as ave

您可以使用数学函数和算术运算符来计算条目。

http://dev.mysql.com/doc/refman/5.7/en/arithmetic-functions.html http://dev.mysql.com/doc/refman/5.7/en/mathematical-functions.html

Answer 2

由于您正在使用时间戳，因此您应该使用UNIX_TIMESTAMP函数。这是一个例子

SELECT UNIX_TIMESTAMP(create_time) - UNIX_TIMESTAMP(change_time) as output

https://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_unix-timestamp

您的最终查询看起来像这样

SELECT
    tn,
    title,
    UNIX_TIMESTAMP(create_time) AS create_time,
    UNIX_TIMESTAMP(change_time) AS change_time,
    UNIX_TIMESTAMP(create_time) - UNIX_TIMESTAMP(change_time) AS time_diff
FROM
    ticket
WHERE
    responsible_user_id = 2
AND ticket_state_id IN (2, 3, 10)
ORDER BY
    change_time DESC

Answer 3

你几乎做到了。

SELECT
    tn,
    title,
    UNIX_TIMESTAMP(create_time) AS create_time,
    UNIX_TIMESTAMP(change_time) AS change_time,
    (UNIX_TIMESTAMP(change_time) - UNIX_TIMESTAMP(create_time)) AS ave
FROM
    ticket
WHERE
    responsible_user_id = 2
AND ticket_state_id IN (2, 3, 10)
ORDER BY
    change_time DESC

Answer 4

假设在for循环中你创建时间为$ createTime [$ i]并将时间更改为$ changeTime [$ i];然后在回显单行中的值后，只需减去这两个变量，该值将为存储在列ave中的特定行中。

mysql相互减去2行并显示在第三行

4 个答案: