我有一张表CAD_CHANGES
ID OBJECT U_ID CH_DATE
1 parcel 20 2017-08-02 15:25:56
2 parcel 20 2017-08-02 10:31:50
3 parcel 20 2017-08-02 18:21:45
4 building 20 2017-08-02 14:03:56
5 building 20 2017-08-02 12:10:10
6 parcel 20 2017-08-02 20:21:56
7 building 20 2017-08-02 21:05:05
8 parcel 20 2017-08-02 09:14:27
9 parcel 20 2017-08-02 12:08:15
10 building 20 2017-08-03 14:09:26
11 building 20 2017-08-03 11:08:37
12 building 20 2017-08-03 18:01:48
13 building 20 2017-08-03 19:05:59
14 building 20 2017-08-03 21:28:02
15 building 20 2017-08-03 23:31:05
16 parcel 20 2017-08-03 09:34:07
17 parcel 20 2017-08-03 20:21:08
18 parcel 20 2017-08-03 15:42:04
19 building 20 2017-08-03 10:51:37
20 parcel 20 2017-08-03 14:10:22
我想以结果为例
ID OBJECT U_ID CH_DATE
--------------------------------------------------------------------------
3 parcel 20 2017-08-02 18:21:45
7 building 20 2017-08-02 21:05:05
---------------------------------------------------------------------------
15 building 20 2017-08-03 23:31:05
17 parcel 20 2017-08-03 20:21:08
我的桌子很大，我只写了两天，请帮忙解决问题， 提前谢谢你
（aaa bbb ccc ddd eee fff）
答案 0 :(得分：1)
像这样的例子
SELECT * FROM CAD_CHANGES WHERE ( OBJECT, CH_DATE ) IN (
SELECT OBJECT, MAX(CH_DATE) FROM CAD_CHANGES GROUP BY OBJECT, TRUNC(CH_DATE))
或者在每个字段上使用像last_value这样的分析函数，但这样写起来会有点痛苦