我有这张表叫做记录:
+---------------------+---------------------+
| date_returned | date_borrowed |
+---------------------+---------------------+
| 2013-05-31 09:27:38 | 2013-05-31 08:48:14 |
| 2013-05-31 09:22:27 | 2013-05-31 08:53:06 |
| 2013-05-31 09:27:38 | 2013-05-31 09:22:35 |
| 2013-05-31 15:27:02 | 2013-05-31 09:22:39 |
| 2013-05-31 15:27:02 | 2013-05-31 10:04:22 |
+---------------------+---------------------+
我想将总小时数作为结果中的另一列。我阅读了手册,但 datediff 似乎含糊不清,只是将差异返回为天。