请教个mysql查询语句
假如现在有个数据库表，列有rowid,user,score,testtime.不同user的多个score按testtime已经插入在这表格。请问怎么找出每个user最近两次的score和对应的testtime。谢谢!

[解决办法]
参考下贴中的多种方法

http://blog.csdn.net/acmain_chm/article/details/4126306
[征集]分组取最大N条记录方法征集，及散分....
[解决办法]

SQL code

root@localhost : test 02:18:41>select * from us;+-------+------+-------+---------------------+| rowid | user | score | testtime            |+-------+------+-------+---------------------+|     1 | a    |    80 | 2012-09-03 14:11:31 ||     2 | a    |    60 | 2012-09-03 14:11:53 ||     3 | a    |    75 | 2012-09-03 14:11:57 ||     4 | b    |    59 | 2012-09-03 14:12:14 ||     5 | b    |    69 | 2012-09-03 14:12:22 ||     6 | b    |    79 | 2012-09-03 14:12:42 ||     7 | c    |    90 | 2012-09-03 14:12:57 ||     8 | c    |    95 | 2012-09-03 14:13:04 ||     9 | d    |    85 | 2012-09-03 14:13:13 |+-------+------+-------+---------------------+9 rows in set (0.00 sec)root@localhost : test 02:18:46>select a.* from us a where 2>(select count(*) from us b where a.user=b.user and  b.testtime > a.testtime );+-------+------+-------+---------------------+| rowid | user | score | testtime            |+-------+------+-------+---------------------+|     2 | a    |    60 | 2012-09-03 14:11:53 ||     3 | a    |    75 | 2012-09-03 14:11:57 ||     5 | b    |    69 | 2012-09-03 14:12:22 ||     6 | b    |    79 | 2012-09-03 14:12:42 ||     7 | c    |    90 | 2012-09-03 14:12:57 ||     8 | c    |    95 | 2012-09-03 14:13:04 ||     9 | d    |    85 | 2012-09-03 14:13:13 |+-------+------+-------+---------------------+
[解决办法]
分组取前两条吧  
SQL code
SELECT a.rowid,a.user,a.score,a.testtime FROM score_us a LEFT JOIN score_us b ON a.user = b.user AND a.testtime < b.testtime GROUP BY a.rowid,a.user,a.score,a.testtime HAVING COUNT(b.rowid) < 2 ORDER BY a.testtime
[解决办法]
root@localhost : test 02:18:46>select a.* from us a where 2>(select count(*) from us b where a.user=b.user and  b.testtime > a.testtime );  
  +


这个可以