如何计算两个时间戳在几天内的差异？我应该使用datetime列吗？
I switched my column to datetime. Simple subtraction doesn't seem to give me a result in days.
mysql> SELECT NOW(), last_confirmation_attempt, NOW() - last_confirmation_attempt AS diff FROM DateClubs HAVING diff IS NOT NULL ;
+---------------------+---------------------------+-----------------+
| NOW() | last_confirmation_attempt | diff |
+---------------------+---------------------------+-----------------+
| 2010-03-30 10:52:31 | 2010-03-16 10:41:47 | 14001084.000000 |
+---------------------+---------------------------+-----------------+
1 row in set (0.00 sec)
我不认为diff是秒，因为当我把diff除以一天中的秒数(86400)时，我不会得到一个感性的答案:
mysql> SELECT NOW(), last_confirmation_attempt, ( NOW() - last_confirmation_attempt) / 86400 AS diff FROM DateClubs HAVING diff IS NOT NULL ;
+---------------------+---------------------------+----------------+
| NOW() | last_confirmation_attempt | diff |
+---------------------+---------------------------+----------------+
| 2010-03-30 10:58:58 | 2010-03-16 10:41:47 | 162.0568402778 |
+---------------------+---------------------------+----------------+
1 row in set (0.00 sec)