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我有一个表是这样的:MySQL的选择组合,并与最新的时间戳
+----+----+---------------------+---------------+
|lid |uid |timestamp |token |
|----+----+---------------------+---------------+
| 10 | 10 | 2014-02-03 12:17:18 | 52efcf118a0ba |
| 45 | 10 | 2014-02-03 12:51:13 | 52efd7046022d |
| 20 | 10 | 2014-02-04 03:47:59 | 52f0a931d3945 |
| 12 | 11 | 2014-02-04 05:21:57 | 52f0bf389371b |
| 34 | 11 | 2014-02-05 06:36:26 | 52f222384fe2d |
| 12 | 11 | 2014-02-05 07:06:42 | 52f229500b403 |
| 32 | 12 | 2014-02-04 05:21:57 | 52f0bf389371b |
| 55 | 12 | 2014-02-05 06:36:26 | 52f222384fe2d |
| 61 | 12 | 2014-02-05 07:06:42 | 52f229500b403 |
盖和UID是外键和表不具有唯一列。
我想选择分组的uid BUT与最新的时间戳。例如,从上面的数据,我只希望这些行:
+----+----+---------------------+---------------+
|lid |uid |timestamp |token |
|----+----+---------------------+---------------+
| 20 | 10 | 2014-02-04 03:47:59 | 52f0a931d3945 |
| 12 | 11 | 2014-02-05 07:06:42 | 52f229500b403 |
| 61 | 12 | 2014-02-05 07:06:42 | 52f229500b403 |
[为每组分组结果获取最多n条记录]的可能重复(http://stackoverflow.com/questions/12113699/get-top-n-records-for-each-group-of-grouped-results ) –
谢谢。没有注意到这一点。我认为这对我有帮助。 –