小编Kai*_*Kai的帖子

我有这个股票价格表(这里是简化版):

+----------+--------+-------+
|   Time   | Ticker | Price |
+----------+--------+-------+
| 10:00:00 | A      |     5 |
| 10:00:01 | A      |     6 |
| 10:00:00 | B      |     3 |
+----------+--------+-------+

我想通过Ticker选择具有最大时间的行组,例如

+----------+--------+-------+
|   Time   | Ticker | Price |
+----------+--------+-------+
| 10:00:01 | A      |     6 |
| 10:00:00 | B      |     3 |
+----------+--------+-------+

我知道如何在SQL中做到这一点,类似的问题可以在这里找到,但我不知道如何在KDB中优雅地做到这一点.

我有一个选择两次的解决方案:

select first Time, first Ticker, first Price by Ticker from (`Time xdesc select Time, Ticker, Price from table where …