问一个简单的列转换为行的问题

create table tb(val int)

insert into tb values(1) 

insert into tb values(2) 

insert into tb values(3 )

insert into tb values(4 )

insert into tb values(5 )

go



declare @sql varchar(8000)

set @sql = ''

select @sql = @sql + ',max(case val when ''' + cast(val as varchar) + ''' then val else 0 end) [' + cast(val as varchar) + ']'

from (select distinct val from tb) as a

set @sql = 'select ' + substring(@sql,2,len(@sql)) + ' from (select id = 1 , val from tb)t group by id'

exec(@sql) 



drop table tb



/*

1           2           3           4           5           

----------- ----------- ----------- ----------- ----------- 

1           2           3           4           5

*/

--1、行互列

--> --> (Roy)生成測試數據

 

if not object_id('Class') is null

    drop table Class

Go

Create table Class([Student] nvarchar(2),[Course] nvarchar(2),[Score] int)

Insert Class

select N'张三',N'语文',78 union all

select N'张三',N'数学',87 union all

select N'张三',N'英语',82 union all

select N'张三',N'物理',90 union all

select N'李四',N'语文',65 union all

select N'李四',N'数学',77 union all

select N'李四',N'英语',65 union all

select N'李四',N'物理',85 

Go

--2000方法:

动态:



declare @s nvarchar(4000)

set @s=''

Select     @s=@s+','+quotename([Course])+'=max(case when [Course]='+quotename([Course],'''')+' then [Score] else 0 end)'

from Class group by[Course]

exec('select [Student]'+@s+' from Class group by [Student]')





生成静态:



select 

    [Student],

    [数学]=max(case when [Course]='数学' then [Score] else 0 end),

    [物理]=max(case when [Course]='物理' then [Score] else 0 end),

    [英语]=max(case when [Course]='英语' then [Score] else 0 end),

    [语文]=max(case when [Course]='语文' then [Score] else 0 end) 

from 

    Class 

group by [Student]



GO

动态:



declare @s nvarchar(4000)

Select     @s=isnull(@s+',','')+quotename([Course]) from Class group by[Course]

exec('select * from Class pivot (max([Score]) for [Course] in('+@s+'))b')



生成静态:

select * 

from 

    Class 

pivot 

    (max([Score]) for [Course] in([数学],[物理],[英语],[语文]))b



生成格式:

/*

Student 数学          物理          英语          语文

------- ----------- ----------- ----------- -----------

李四      77          85          65          65

张三      87          90          82          78



(2 行受影响)

*/



------------------------------------------------------------------------------------------

go

--加上总成绩(学科平均分)



--2000方法:

动态:



declare @s nvarchar(4000)

set @s=''

Select     @s=@s+','+quotename([Course])+'=max(case when [Course]='+quotename([Course],'''')+' then [Score] else 0 end)'

from Class group by[Course]

exec('select [Student]'+@s+',[总成绩]=sum([Score])  from Class group by [Student]')--加多一列(学科平均分用avg([Score]))



生成动态:



select 

    [Student],

    [数学]=max(case when [Course]='数学' then [Score] else 0 end),

    [物理]=max(case when [Course]='物理' then [Score] else 0 end),

    [英语]=max(case when [Course]='英语' then [Score] else 0 end),

    [语文]=max(case when [Course]='语文' then [Score] else 0 end),

    [总成绩]=sum([Score]) --加多一列(学科平均分用avg([Score]))

from 

    Class 

group by [Student]



go



--2005方法:



动态:



declare @s nvarchar(4000)

Select     @s=isnull(@s+',','')+quotename([Course]) from Class group by[Course] --isnull(@s+',','') 去掉字符串@s中第一个逗号

exec('select [Student],'+@s+',[总成绩] from (select *,[总成绩]=sum([Score])over(partition by [Student]) from Class) a 

pivot (max([Score]) for [Course] in('+@s+'))b ')



生成静态:



select 

    [Student],[数学],[物理],[英语],[语文],[总成绩] 

from 

    (select *,[总成绩]=sum([Score])over(partition by [Student]) from Class) a --平均分时用avg([Score])

pivot 

    (max([Score]) for [Course] in([数学],[物理],[英语],[语文]))b 



生成格式:



/*

Student 数学          物理          英语          语文          总成绩

------- ----------- ----------- ----------- ----------- -----------

李四      77          85          65          65          292

张三      87          90          82          78          337



(2 行受影响)

*/



go



--2、列转行

--> --> (Roy)生成測試數據

 

if not object_id('Class') is null

    drop table Class

Go

Create table Class([Student] nvarchar(2),[数学] int,[物理] int,[英语] int,[语文] int)

Insert Class

select N'李四',77,85,65,65 union all

select N'张三',87,90,82,78

Go



--2000:



动态:



declare @s nvarchar(4000)

select @s=isnull(@s+' union all ','')+'select [Student],[Course]='+quotename(Name,'''')--isnull(@s+' union all ','') 去掉字符串@s中第一个union all

+',[Score]='+quotename(Name)+' from Class'

from syscolumns where ID=object_id('Class') and Name not in('Student')--排除不转换的列

order by Colid

exec('select * from ('+@s+')t order by [Student],[Course]')--增加一个排序



生成静态:

select * 

from (select [Student],[Course]='数学',[Score]=[数学] from Class union all 

select [Student],[Course]='物理',[Score]=[物理] from Class union all 

select [Student],[Course]='英语',[Score]=[英语] from Class union all 

select [Student],[Course]='语文',[Score]=[语文] from Class)t 

order by [Student],[Course]



go

--2005:



动态:



declare @s nvarchar(4000)

select @s=isnull(@s+',','')+quotename(Name)

from syscolumns where ID=object_id('Class') and Name not in('Student') 

order by Colid

exec('select Student,[Course],[Score] from Class unpivot ([Score] for [Course] in('+@s+'))b')



go

select 

    Student,[Course],[Score] 

from 

    Class 

unpivot 

    ([Score] for [Course] in([数学],[物理],[英语],[语文]))b



生成格式:

/*

Student Course Score

------- ------- -----------

李四      数学      77

李四      物理      85

李四      英语      65

李四      语文      65

张三      数学      87

张三      物理      90

张三      英语      82

张三      语文      78



(8 行受影响)

*/

----------------------------------------------------------------

-- Author  :fredrickhu(我是小F，向高手学习)

-- Date    :2009-10-21 14:15:21

-- Version:

--      Microsoft SQL Server 2005 - 9.00.4035.00 (Intel X86) 

--	Nov 24 2008 13:01:59 

--	Copyright (c) 1988-2005 Microsoft Corporation

--	Developer Edition on Windows NT 5.2 (Build 3790: Service Pack 1)

--

----------------------------------------------------------------

--> 测试数据：[tb]

if object_id('[tb]') is not null drop table [tb]

go 

create table [tb]([col] int)

insert [tb]

select 1 union all

select 2 union all

select 3 union all

select 4 union all

select 5

--------------开始查询--------------------------

declare @s varchar(10)

select @s=isnull(@s+' ','')+ltrim(col) from tb

select @s

----------------结果----------------------------

/*----------

1 2 3 4 5 

*/

declare @s varchar(1000)

select @s=isnull(@s+' ','')+ltrim(col) from tb



select @s