Sql server 使用聚合函数在同一个表上进行两次内部联接

作为sql新手用户：

我有一个简单的表格，每天晚上储存一些记录。表:

表：T1

+----+-----+----+-----------+------------+
| Id |  A  | AB |   Value   |    Date    |
+----+-----+----+-----------+------------+
|  1 | abc | I  | -48936.08 | 2013-06-24 |
|  2 | def | A  | 431266.19 | 2013-06-24 |
|  3 | xyz | I  | -13523.90 | 2013-06-24 |
|  4 | abc | A  | 13523.90  | 2013-06-23 |
|  5 | xyz | I  | -13523.90 | 2013-06-23 |
|  6 | def | A  | 13523.90  | 2013-06-22 |
|  7 | def | I  | -13523.90 | 2013-06-22 |
+----+-----+----+-----------+------------+

我想获得列A，AB的所有值，在AB=I上过滤的列A上最新日期的值

基本上，结果应该如下所示：

+----+-----+----+-----------+------------+
| Id |  A  | AB |   Value   |    Date    |
+----+-----+----+-----------+------------+
|  1 | abc | I  | -48936.08 | 2013-06-24 |
|  3 | xyz | I  | -13523.90 | 2013-06-24 |
|  7 | def | I  | -13523.90 | 2013-06-22 |
+----+-----+----+-----------+------------+

我曾两次尝试在同一个表上使用内部联接，但都没有得到正确的结果

任何帮助都将不胜感激

---

谢谢：）

这将适用于SQLServer2005+

;WITH a as
(
SELECT id, A,AB, Value, Date
, row_number() over (partition by A order by Date desc) rn
FROM t1
WHERE AB = 'I'
)
SELECT id, A,AB, Value, Date
FROM a WHERE rn = 1

---

哦，天哪，太慢了，被同样的回答打败了！这里的网络礼仪是什么？我应该删除我的帖子吗？

; WITH x AS (
  SELECT id
       , a
       , ab
       , "value"
       , "date"
       , Row_Number() OVER (PARTITION BY a ORDER BY "date" DESC) As row_num
  FROM   your_table
  WHERE  ab = 'I'
)
SELECT *
FROM   x
WHERE  row_num = 1