仅在MYSQL DATEDIFF中显示小时数

Question

我已经忙了好几个小时,但是我无法让它发挥作用.

SQL

SELECT DATEDIFF(end_time, start_time) as `difference` FROM timeattendance WHERE timeattendance_id = '1484'

start_time =   2012-01-01   12:00:00
end_time =     2012-01-02   13:00:00

差异是25(小时).但我得到的输出是1(天).

我怎样才能获得25小时的输出？

Answer 1

那么使用TIMESTAMPDIFF呢？

SELECT TIMESTAMPDIFF(HOUR, start_time, end_time) 
           as `difference` FROM timeattendance WHERE timeattendance_id = '1484'

Answer 2

您最好使用TIMEDIFF而不是DATEDIFF,因为DATEDIFF会在比较之前将所有时间都转换为日期.执行TIMEDIFF后,您可以获得具有HOUR功能的小时数.

SELECT HOUR(TIMEDIFF(end_time, start_time)) as `difference`;

Answer 3

正如 MySQL参考中所述，DATEDIFF只需要几天的时间。

如果两个日期都在 1970 年之后，您可以减去时间戳：

SELECT ( UNIX_TIMESTAMP("2012-01-02 13:00:00") - 
         UNIX_TIMESTAMP("2012-01-01 12:00:00") ) / 3600 ...

或者：

SELECT TIMEDIFF ( "2012-01-02 13:00:00", "2012-01-01 12:00:00") / 3600 ... 

Answer 4

您可以使用 TIMEDIFF 和 HOUR 函数来提取小时。

SELECT HOUR(TIMEDIFF(end_time, start_time)) as `difference` FROM timeattendance WHERE timeattendance_id = '1484'

http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_timediff
http://dev.mysql.com/doc/refman/5.5/en/date-and -time-functions.html#function_hour