请教一个SQL多列转化成固定行的问题！
SQL 如下
表 Tb 两列 ID Name
1 A
1 B
1 C
1 D
1 E
2 F
2 G
2 H
2 I
3 J
3 K
3 L
4 M
5 N
5 O
需要排列的结果是
表 TC ID Name1 Name2 Name3
1 A B C
1 D E null
2 F G H
2 I null null
3 J K L
4 M null null
5 N O null
其中ID中的行数是不固定的，有高手支个招么？非常谢谢！
[解决办法]
--参照这个 自己写
/*
标题：普通行列转换(version 2.0)
作者：爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开)
时间：2008-03-09
地点：广东深圳
说明：普通行列转换(version 1.0)仅针对sql server 2000提供静态和动态写法，version 2.0增加sql server 2005的有关写法。
问题：假设有张学生成绩表(tb)如下:
姓名 课程 分数
张三 语文 74
张三 数学 83
张三 物理 93
李四 语文 74
李四 数学 84
李四 物理 94
想变成(得到如下结果)：
姓名 语文 数学 物理
---- ---- ---- ----
李四 74 84 94
张三 74 83 93
-------------------
*/
create table tb(姓名 varchar(10) , 课程 varchar(10) , 分数 int)
insert into tb values('张三' , '语文' , 74)
insert into tb values('张三' , '数学' , 83)
insert into tb values('张三' , '物理' , 93)
insert into tb values('李四' , '语文' , 74)
insert into tb values('李四' , '数学' , 84)
insert into tb values('李四' , '物理' , 94)
go
--SQL SERVER 2000 静态SQL,指课程只有语文、数学、物理这三门课程。(以下同)
select 姓名 as 姓名 ,
max(case 课程 when '语文' then 分数 else 0 end) 语文,
max(case 课程 when '数学' then 分数 else 0 end) 数学,
max(case 课程 when '物理' then 分数 else 0 end) 物理
from tb
group by 姓名
--SQL SERVER 2000 动态SQL,指课程不止语文、数学、物理这三门课程。(以下同)
declare @sql varchar(8000)
set @sql = 'select 姓名 '
select @sql = @sql + ' , max(case 课程 when ''' + 课程 + ''' then 分数 else 0 end) [' + 课程 + ']'
from (select distinct 课程 from tb) as a
set @sql = @sql + ' from tb group by 姓名'
exec(@sql)
--SQL SERVER 2005 静态SQL。
select * from (select * from tb) a pivot (max(分数) for 课程 in (语文,数学,物理)) b
--SQL SERVER 2005 动态SQL。
declare @sql varchar(8000)
select @sql = isnull(@sql + '],[' , '') + 课程 from tb group by 课程
set @sql = '[' + @sql + ']'
exec ('select * from (select * from tb) a pivot (max(分数) for 课程 in (' + @sql + ')) b')
---------------------------------
create table #TB( id int, [name] varchar(50))insert into #TBselect 1,'A' union all select 1,'B' union all select 1,'C' union all select 1,'D' union all select 1,'E' union all select 2,'F' union all select 2,'G' union all select 2,'H' union all select 2,'I' union all select 3,'J' union all select 3,'K' union all select 3,'L' union all select 4,'M' union all select 5,'N' union all select 5,'O'create table #TC( GroupID int, ID int, [name] varchar(50)) declare @i intdeclare @ID intset @i=0Declare iCursor Cursor For Select Distinct ID from #TBOpen iCursorFetch next from iCursor into @IDWhile @@Fetch_Status=0Begin Insert Into #TC select ((row-1)/3)+@i,ID,[Name] from (select row_number() over (partition by ID order by id) as row,* from #TB) B where ID=@ID select @i=max(GroupID)+1 from #TC Print @i Fetch Next from iCursor into @IDEndClose iCursorDeallocate iCursorselect GroupID,id, max(case row%3 when 1 then [name] else null end) as name1, max(case row%3 when 2 then [name] else null end) as name2, max(case row%3 when 0 then [name] else null end) as name3 from (select row_number() over (partition by ID order by id) as row,* from #TC) bgroup by GroupID,idGroupID id name1 name2 name30 1 A B C1 1 D E NULL2 2 F G H3 2 I NULL NULL4 3 J K L5 4 M NULL NULL6 5 N O NULL
[解决办法]
DECLARE @TB TABLE([ID] INT, [Name] VARCHAR(1))INSERT @TB SELECT 1, 'A' UNION ALL SELECT 1, 'B' UNION ALL SELECT 1, 'C' UNION ALL SELECT 1, 'D' UNION ALL SELECT 1, 'E' UNION ALL SELECT 2, 'F' UNION ALL SELECT 2, 'G' UNION ALL SELECT 2, 'H' UNION ALL SELECT 2, 'I' UNION ALL SELECT 3, 'J' UNION ALL SELECT 3, 'K' UNION ALL SELECT 3, 'L' UNION ALL SELECT 4, 'M' UNION ALL SELECT 5, 'N' UNION ALL SELECT 5, 'O'SELECT *,SEQ=IDENTITY(int,1,1) INTO # FROM @TB SELECT ID, MAX(CASE WHEN (SEQ-1)%3=0 THEN NAME END) AS NAME1, MAX(CASE WHEN (SEQ-1)%3=1 THEN NAME END) AS NAME2, MAX(CASE WHEN (SEQ-1)%3=2 THEN NAME END) AS NAME3FROM (SELECT ID,NAME,SEQ=SEQ-(SELECT COUNT(*) FROM # WHERE ID<TA.ID) FROM # TA) TBGROUP BY ID,(SEQ-1)/3ORDER BY IDDROP TABLE #/*ID NAME1 NAME2 NAME3----------- ----- ----- -----1 A B C1 D E NULL2 F G H2 I NULL NULL3 J K L4 M NULL NULL5 N O NULL*/
[解决办法]
--借楼上数据一用，写段动态的吧
DECLARE @TB TABLE([ID] INT, [Name] VARCHAR(1))
INSERT @TB
SELECT 1, 'A' UNION ALL
SELECT 1, 'B' UNION ALL
SELECT 1, 'C' UNION ALL
SELECT 1, 'D' UNION ALL
SELECT 1, 'E' UNION ALL
SELECT 2, 'F' UNION ALL
SELECT 2, 'G' UNION ALL
SELECT 2, 'H' UNION ALL
SELECT 2, 'I' UNION ALL
SELECT 3, 'J' UNION ALL
SELECT 3, 'K' UNION ALL
SELECT 3, 'L' UNION ALL
SELECT 4, 'M' UNION ALL
SELECT 5, 'N' UNION ALL
SELECT 5, 'O'
SELECT *,sign=(c-1)/3,sign1=(c-1)%3
INTO #
FROM(SELECT *,C=(SELECT COUNT(1) FROM @TB WHERE A.ID=ID AND NAME <=A.NAME) FROM @TB A)A
DECLARE @s VARCHAR(1000)
SELECT @S='SELECT ID,sign'
SELECT @s=@s+',MAX(CASE WHEN LTRIM(sign1)='''+LTRIM(sign1)+''' THEN name ELSE null END)AS ''NAME'+ltrim(sign1+1)+''' '
FROM # GROUP BY sign1
SET @S=@s+' FROM # GROUP BY ID,sign '
SET @s='SELECT ID,NAME1,NAME2,NAME3 FROM ('+@S+')A ORDER BY id'
EXEC(@S)
/*
ID NAME1 NAME2 NAME3
----------- ----- ----- -----
1 A B C
1 D E NULL
2 F G H
2 I NULL NULL
3 J K L
4 M NULL NULL
5 N O NULL
警告: 聚合或其它 SET 操作消除了空值。
*/
Select Distinct ID from #TB
Open iCursor
Fetch next from iCursor into @ID
While @@Fetch_Status=0
Begin
Insert Into #TC
select ((row-1)/3)+@i,ID,[Name] from (select row_number() over (partition by ID order by id) as row,* from #TB) B
where ID=@ID
select @i=max(GroupID)+1 from #TC
Print @i
Fetch Next from iCursor into @ID
End
Close iCursor
Deallocate iCursor
select GroupID,id,
max(case row%3 when 1 then [name] else null end) as name1,
max(case row%3 when 2 then [name] else null end) as name2,
max(case row%3 when 0 then [name] else null end) as name3
from (select row_number() over (partition by ID order by id) as row,* from #TC) b
group by GroupID,id
GroupID id name1 name2 name3
0 1 A B C
1 1 D E NULL
2 2 F G H
3 2 I NULL NULL
4 3 J K L
5 4 M NULL NULL
6 5 N O NULL
