还是那道有趣的题目

数据记录是这样的
1
2
3
4
5
12
17
18
19
20
25
请问sqlserver2000如何显示成这样
1-5
12
17-20
25

 
DECLARE @t TABLE(num INT)
INSERT INTO @t
SELECT 1 
UNION ALL
SELECT 2 
UNION ALL
SELECT 3 
UNION ALL
SELECT 4 
UNION ALL
SELECT 5 
UNION ALL
SELECT 12 
UNION ALL
SELECT 17 
UNION ALL
SELECT 18 
UNION ALL
SELECT 19 
UNION ALL
SELECT 20 
UNION ALL
SELECT 25 
 

 

SELECT CASE
WHEN MIN(num) = MAX(num) THEN CAST(MIN(num) AS VARCHAR)
ELSE CAST(MIN(num) AS VARCHAR) + '-' + CAST(MAX(num) AS VARCHAR)
END
FROM (
SELECT *, (num -id) AS iid
FROM (
SELECT (SELECT COUNT(1) FROM @t t1 WHERE t1.num<=t2.num) AS id,
*
FROM @t t2
) t3
) t4
GROUP BY
iid

题目来源

 http://blog.csdn.net/fredrickhu/article/details/6481452