原文:在论坛中出现的比较难的sql问题：3(row_number函数 分组查询)
最近，在论坛中，遇到了不少比较难的sql问题，虽然自己都能解决，但发现过几天后，就记不起来了，也忘记解决的方法了。
所以，觉得有必要记录下来，这样以后再次碰到这类问题，也能从中获取解答的思路。另外，考虑到前2篇太长，看起来不太方便，所以拆分为第3篇
1、分组查询问题
http://bbs.csdn.net/topics/390619682?page=1#post-395835328
例子表结构数据如下：
id status date price
1 1 2013-10-01 218
2 1 2013-10-02 218
3 0 2013-10-03 218
4 0 2013-10-04 238
5 0 2013-10-05 238
6 0 2013-10-06 238
7 0 2013-10-07 258
8 0 2013-10-08 258
9 0 2013-10-09 218
想获取的结果集一：
2013-10-01至2013-10-03 218
2013-10-04至2013-10-06 238
2013-10-07至2013-10-08 258
2013-10-09至2013-10-09 218
想获取的结果集二：
1 2013-10-01至2013-10-02 218
0 2013-10-03至2013-10-03 218
0 2013-10-04至2013-10-06 238
0 2013-10-07至2013-10-08 258
0 2013-10-09至2013-10-09 218
我的解法：
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--drop table tb
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create table tb(id int,status int,date varchar(10),price int)
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insert into tb
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select 1, 1, '2013-10-01', 218 union all
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select 2, 1, '2013-10-02', 218 union all
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select 3, 0, '2013-10-03', 218 union all
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select 4, 0, '2013-10-04', 238 union all
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select 5, 0, '2013-10-05', 238 union all
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select 6, 0, '2013-10-06', 238 union all
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select 7, 0, '2013-10-07', 258 union all
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select 8, 0, '2013-10-08', 258 union all
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select 9, 0, '2013-10-09', 218 --union all
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--select 10, 0, '2013-10-10', 218
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go
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--第一个结果集
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;with t
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as
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(
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select *,
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row_number() over(partition by price order by id) as rownum,
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min(id) over(partition by price) as min_id
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from tb
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),
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tt
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as
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(
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select id,
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price,
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a.date,
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rownum - (id - min_id) as interval
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from t a
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)
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select min(date) + '至' + max(date) as date,
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price
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from tt
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group by price,interval
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order by 1
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/*
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date price
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2013-10-01至2013-10-03 218
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2013-10-04至2013-10-06 238
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2013-10-07至2013-10-08 258
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2013-10-09至2013-10-09 218
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*/
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-
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--第2个结果集
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;with t
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as
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(
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select *,
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row_number() over(partition by status,price order by id) as rownum,
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min(id) over(partition by status,price) as min_id
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from tb
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),
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tt
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as
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(
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select id,
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price,
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a.date,
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a.status,
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rownum - (id - min_id) as interval
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from t a
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)
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select status,min(date) + '至' + max(date),price
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from tt
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group by status,price,interval
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order by 2
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/*
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status date price
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1 2013-10-01至2013-10-02 218
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0 2013-10-03至2013-10-03 218
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0 2013-10-04至2013-10-06 238
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0 2013-10-07至2013-10-08 258
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0 2013-10-09至2013-10-09 218
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*/
2、查询出一段数据后判断记录里面的最大id,是否大于值a 查询语句如下：
http://bbs.csdn.net/topics/390619191
select top 200 id, ClassId,Name,Price,BoxContain,BoxLength,BoxWidth,BoxHeight,CName,EName,CPack,PhotoFolder,EPack,0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08 from ProductData where ClassId=101 and BoxContain >0 and BoxContain is not null and round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3) >=0 And round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3) <= 10000 and (0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08) >=10 and (0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08) <=1000 and EPack='Window Box' order by id asc
我的解法，适用于SQL Server 2000：
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select *
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from
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(
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select top 200 id, ClassId,Name,Price,BoxContain,BoxLength,BoxWidth,BoxHeight,CName,EName,CPack,PhotoFolder,EPack,
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0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08
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from ProductData
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where ClassId=101 and BoxContain >0 and BoxContain is not null
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and round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3) >=0
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And round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3) <= 10000
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and (0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08) >=10
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and (0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08) <=1000
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and EPack='Window Box'
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order by id asc
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)t
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where
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(
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select max(id)
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from
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(
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select top 200 id, ClassId,Name,Price,BoxContain,BoxLength,BoxWidth,BoxHeight,CName,EName,CPack,PhotoFolder,EPack,
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0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08
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from ProductData
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where ClassId=101 and BoxContain >0 and BoxContain is not null
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and round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3) >=0
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And round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3) <= 10000
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and (0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08) >=10
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and (0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08) <=1000
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and EPack='Window Box'
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order by id asc
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)t
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) > a