我有一张桌子,看起来如下
state_history
+---------------------+-----------+----------------+ +
| state_added_time | entity_id | state_id | .... |
+---------------------+-----------+----------------+ |
| 2015-05-15 13:24:22 | 1 | 1 | |
| 2015-05-15 13:29:44 | 3 | 2 | |
| 2015-05-15 13:34:26 | 2 | 2 | |
| 2015-05-15 14:24:28 | 1 | 3 | |
| 2015-05-15 14:24:30 | 2 | 3 | |
| 2015-05-15 14:26:32 | 3 | 5 | |
| 2015-05-15 14:26:34 | 3 | 3 | |
.......
我的目的是在任何特定时间了解所有实体的状态.例如,如果从应用程序收到的时间戳是 …