WITH test (ID,    [Date])
 AS 
 (
 SELECT 1,    '2012-3-10'
 UNION ALL SELECT 1,    '2012-3-10'
 UNION ALL SELECT 1,    '2012-3-4'
 UNION ALL SELECT 2,    '2012-2-10'
 UNION ALL SELECT 2,    '2012-2-10'
 UNION ALL SELECT 2,    '2012-3-8'
 UNION ALL SELECT 2,    '2012-3-9'
 UNION ALL SELECT 3,    '2012-5-12'
 UNION ALL SELECT 3,    '2012-4-12'
 UNION ALL SELECT 3,    '2012-1-2'
 UNION ALL SELECT 4,    '2012-5-5'
 UNION ALL SELECT 5,    '2012-3-7'
 UNION ALL SELECT 6,    '2012-4-2'
 UNION ALL SELECT 7,    '2012-2-1'
 )
 SELECT id,MIN ([Date])[Date]
 FROM Test 
 GROUP BY id
 
 /*
 id          Date
 ----------- ---------
 1           2012-3-10
 2           2012-2-10
 3           2012-1-2
 4           2012-5-5
 5           2012-3-7
 6           2012-4-2
 7           2012-2-1
 
 (7 行受影响)
 */

------解决方案--------------------
探讨

1楼的结果不对

SQL code

WITH test (ID,    [Date])
 AS 
 (
 SELECT 1,    '2012-3-10'
 UNION ALL SELECT 1,    '2012-3-10'
 UNION ALL SELECT 1,    '2012-3-4'
 UNION ALL SELECT 2,    '2012-2-10'
 UN……


------解决方案--------------------
探讨

原来倒序了.....我说怎么执行你的和楼主结果不一样呢