Sqlserver 纯粹意义上的行列转换--【叶子】
首先还是用例子来说明一下这个我所谓的“纯粹意义”
假设有下面这样一个表：
CID AID Q
---- ---- -----------
C1 M1 1
C2 M1 2
C3 M1 3
C4 M2 1
C5 M2 2
我们要得到的效果是这样的：
字段 1 2 3 4 5
---- ---- ---- ---- ---- ----
AID M1 M1 M1 M2 M2
Q 1 2 3 1 2
CID C1 C2 C3 C4 C5
就是列变行，不需要做其他处理。
下面示例可以实现这个效果：
declare @C table (CID varchar(2),AID varchar(2),Q int)
insert into @C
select 'C1','M1',1 union all
select 'C2','M1',2 union all
select 'C3','M1',3 union all
select 'C4','M2',1 union all
select 'C5','M2',2
select * from @C
;with C as
(
select row_number()over(order by CID) row,CID from @C
)
select
'CID' as 字段,
[1]=Max(case when row%6=1 then RTRIM(CID) else '' end),
[2]=Max(case when row%6=2 then RTRIM(CID) else '' end),
[3]=Max(case when row%6=3 then RTRIM(CID) else '' end),
[4]=Max(case when row%6=4 then RTRIM(CID) else '' end),
[5]=Max(case when row%6=5 then RTRIM(CID) else '' end) into #t
from
C
group by (row-1)/6
;with D as
(
select row_number()over(order by CID) row,AID from @C
)
insert into #t
select
'AID' as 字段,
[1]=Max(case when row%6=1 then RTRIM(AID) else '' end),
[2]=Max(case when row%6=2 then RTRIM(AID) else '' end),
[3]=Max(case when row%6=3 then RTRIM(AID) else '' end),
[4]=Max(case when row%6=4 then RTRIM(AID) else '' end),
[5]=Max(case when row%6=5 then RTRIM(AID) else '' end)
from
D
group by (row-1)/6
;with E as
(
select row_number()over(order by CID) row,Q from @C
)
insert into #t
select
'Q' as 字段,
[1]=Max(case when row%6=1 then RTRIM(Q) else '' end),
[2]=Max(case when row%6=2 then RTRIM(Q) else '' end),
[3]=Max(case when row%6=3 then RTRIM(Q) else '' end),
[4]=Max(case when row%6=4 then RTRIM(Q) else '' end),
[5]=Max(case when row%6=5 then RTRIM(Q) else '' end)
from
E
group by (row-1)/6
select * from #t
drop table #t
/*
CID AID Q
---- ---- -----------
C1 M1 1
C2 M1 2
C3 M1 3
C4 M2 1
C5 M2 2
字段 1 2 3 4 5
---- ---- ---- ---- ---- ----
AID M1 M1 M1 M2 M2
Q 1 2 3 1 2
CID C1 C2 C3 C4 C5
*/
我们也可以在创建一个表来放表结构。
declare @表结构table (字段varchar(5),类型varchar(7))
insert into @表结构
select 'CID','varchar' union all
select 'AID','varchar' union all
select 'Q','int' union all
select 'CName','varchar'
select * from @表结构
declare @C table (CID varchar(2),AID varchar(2),Q int)
insert into @C
select 'C1','M1',1 union all
select 'C2','M1',2 union all
select 'C3','M1',3 union all
select 'C4','M2',1 union all
select 'C5','M2',2
select * from @C
;with C as
(
select row_number()over(order by CID) row,CID from @C
)
select
'CID' as 字段,
[1]=Max(case when row%6=1 then RTRIM(CID) else '' end),
[2]=Max(case when row%6=2 then RTRIM(CID) else '' end),
[3]=Max(case when row%6=3 then RTRIM(CID) else '' end),
[4]=Max(case when row%6=4 then RTRIM(CID) else '' end),
[5]=Max(case when row%6=5 then RTRIM(CID) else '' end) into #t
from
C
group by (row-1)/6
;with D as
(
select row_number()over(order by CID) row,AID from @C
)
insert into #t
select
'AID' as 字段,
[1]=Max(case when row%6=1 then RTRIM(AID) else '' end),
[2]=Max(case when row%6=2 then RTRIM(AID) else '' end),
[3]=Max(case when row%6=3 then RTRIM(AID) else '' end),
[4]=Max(case when row%6=4 then RTRIM(AID) else '' end),
[5]=Max(case when row%6=5 then RTRIM(AID) else '' end)
from
D
group by (row-1)/6
;with E as
(
select row_number()over(order by CID) row,Q from @C
)
insert into #t
select
'Q' as 字段,
[1]=Max(case when row%6=1 then RTRIM(Q) else '' end),
[2]=Max(case when row%6=2 then RTRIM(Q) else '' end),
[3]=Max(case when row%6=3 then RTRIM(Q) else '' end),
[4]=Max(case when row%6=4 then RTRIM(Q) else '' end),
[5]=Max(case when row%6=5 then RTRIM(Q) else '' end)
from
E
group by (row-1)/6
select * from @表结构a left join #t b on a.字段=b.字段
drop table #t
/*
字段 类型
----- -------
CID varchar
AID varchar
Q int
CName varchar
CID AID Q
---- ---- -----------
C1 M1 1
C2 M1 2
C3 M1 3
C4 M2 1
C5 M2 2
字段 类型 字段 1 2 3 4 5
----- ------- ---- ---- ---- ---- ---- ----
CID varchar CID C1 C2 C3 C4 C5
AID varchar AID M1 M1 M1 M2 M2
Q int Q 1 2 3 1 2
CName varchar NULL NULL NULL NULL NULL NULL
*/
@【叶子】http://blog.csdn.net/maco_wang 原创作品，转贴请注明作者和出处，留此信息。