见：http://topic.csdn.net/u/20100625/21/cb7295e6-0514-4e28-888f-2935537208f4.html
有个表pages ,有5个属性，id, url, title, body, site.
问： 用一条SQL语句搜出url,body,或site中包含’test’字符串的数据，且将含有‘test’的url 的结果放在最前面,其次是body, 然后是site 且不能有重复数据
- 如：
id url title body site
1 'a' 'b' 'c' 'd'
2 'a' 'b' 'c' 'test'
3 'a' 'b' 'test' 'd'
4 'ftest' 'b' 'c' 'd'
5 'test' 'b' 'test' 'test'
搜出的结果是：
id url title body site
4 'ftest' 'b' 'c' 'd'
5 'test' 'b' 'test' 'test'
3 'a' 'b' 'test' 'd'
2 'a' 'b' 'c' 'test'
============================================================
创建测试数据：
CREATE TABLE pages(id int,url nvarchar(100),Title nvarchar(100),body nvarchar(100),site nvarchar(100))
INSERT pages SELECT 1, 'a', 'b','c','d'
UNION ALL SELECT 2, 'a', 'b','c','test'
UNION ALL SELECT 3, 'a', 'b','test','d'
UNION ALL SELECT 4, 'ftest', 'b','c','d'
UNION ALL SELECT 5, 'ftest', 'b','test','test'
UNION ALL SELECT 6, 'fffffffffff', 'testb','testc','d'
GO
执行查询：
(1)
select * from pages
id url Title body site
----------------------------------------------------------------------
1 a b c d
2 a b c test
3 a b test d
4 ftest b c d
5 ftest b test test
6 fffffffffff testb testc d
(6 行受影响)
(2)
select * from pages where url like '%test%' or body like '%test%' or site like '%test%'
order by case
when url like '%test%' then 0
when body like '%test%' then 1
when site like '%test%' then 2 end
id url Title body site
-----------------------------------------------------------------------
4 ftest b c d
5 ftest b test test
6 fffffffffff testb testc d
3 a b test d
2 a b c test
(5 行受影响)