mysql - 如何获取 MySQL 组中的最后一条记录

Question

我需要一些帮助:假设我有以下记录:

Driver  Date    Consultant
1   1/01/2010   A
1   3/04/2010   A
1   3/04/2010   A
1   25/06/2012  B
2   24/03/2012  C
3   13/01/2012  A
3   15/01/2012  B
3   15/01/1012  C

Date 和 Consultant 来自 QUOTES 表，Driver 来自 DRIVER 表。由驱动程序 ID 关联。

我需要让结果集看起来如下:

Driver  Quote Count First date  Last Date   Consultant
1          4        1/01/2010   25/06/2012  B
2          1        24/03/2012  24/03/2012  C
3          3        13/01/2012  15/01/1012  C

在 MySQL 中，如何让结果集中的顾问成为最后一个处理 QUOTE 的顾问？

Answer 1

可以通过显式连接来做到这一点:

select q.*, t.consultant
from (select driver, count(*) as quotecount, min(date) as FirstDate, max(date) as lastdate
      from t
      group by driver
     ) q join
     t
     on t.driver = q.driver and t.date = q.lastdate