在 PostgreSQL 9.4 上，我试图在一些连续的行上实现我称之为“聚合函数”的东西。例子：
输入数据：
recipe prod1 prod2 timestamp
0 5 4 2015-07-02 08:10:34.357
0 2 7 2015-07-02 08:13:45.352
0 7 0 2015-07-02 08:16:22.098
1 3 2 2015-07-02 08:22:14.678
1 9 4 2015-07-02 08:22:56.123
2 2 6 2015-07-02 08:26:37.564
2 1 7 2015-07-02 08:27:33.109
2 0 8 2015-07-02 08:31:11.687
0 3 5 2015-07-02 08:40:01.345
1 4 2 2015-07-02 08:42:23.210
期望的输出：
recipe prod1_sum prod2_avg timestamp_first timestamp_last
0 14 3.6666 2015-07-02 08:10:34.357 2015-07-02 08:16:22.098
1 12 3 2015-07-02 08:22:14.678 2015-07-02 08:22:56.123
2 …