--带符号合并行列转换--有表t,其数据如下:
a b
1 1
1 2
1 3
2 1
2 2
3 1
--如何转换成如下结果:
a b
1 1,2,3
2 1,2
3 1 create table tb
(
a int,
b int
)
insert into tb(a,b) values(1,1)
insert into tb(a,b) values(1,2)
insert into tb(a,b) values(1,3)
insert into tb(a,b) values(2,1)
insert into tb(a,b) values(2,2)
insert into tb(a,b) values(3,1)
goif object_id('pubs..f_hb') is not null
drop function f_hb
go--创建一个合并的函数
create function f_hb(@a int)
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',' + cast(b as varchar) from tb where a = @a
set @str = right(@str , len(@str) - 1)
return(@str)
End
go--调用自定义函数得到结果:
select distinct a ,dbo.f_hb(a) as b from tbdrop table tb--结果
a b
----------- ------
1 1,2,3
2 1,2
3 1(所影响的行数为 3 行)
多个前列的合并
数据的原始状态如下:
ID PR CON OP SC
001 p c 差 6
001 p c 好 2
001 p c 一般 4
002 w e 差 8
002 w e 好 7
002 w e 一般 1
===========================
用SQL语句实现,变成如下的数据
ID PR CON OPS
001 p c 差(6),好(2),一般(4)
002 w e 差(8),好(7),一般(1)if object_id('pubs..tb') is not null
drop table tb
gocreate table tb
(
id varchar(10),
pr varchar(10),
con varchar(10),
op varchar(10),
sc int
)
insert into tb(ID,PR,CON,OP,SC) values('001', 'p', 'c', '差', 6)
insert into tb(ID,PR,CON,OP,SC) values('001', 'p', 'c', '好', 2)
insert into tb(ID,PR,CON,OP,SC) values('001', 'p', 'c', '一般', 4)
insert into tb(ID,PR,CON,OP,SC) values('002', 'w', 'e', '差', 8)
insert into tb(ID,PR,CON,OP,SC) values('002', 'w', 'e', '好', 7)
insert into tb(ID,PR,CON,OP,SC) values('002', 'w', 'e', '一般', 1)
goif object_id('pubs..test') is not null
drop table test
go
select ID,PR,CON , OPS = op + '(' + cast(sc as varchar(10)) + ')' into test from tb--创建一个合并的函数
if object_id('pubs..f_hb') is not null
drop function f_hb
go
create function f_hb(@id varchar(10),@pr varchar(10),@con varchar(10))
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',' + cast(OPS as varchar) from test where id = @id and @pr = pr and @con = con
set @str = right(@str , len(@str) - 1)
return(@str)
End
go--调用自定义函数得到结果:
select distinct id ,pr , con , dbo.f_hb(id,pr,con) as OPS from testdrop table tb
drop table test--结果
id pr con OPS
---------- ---------- ---------- -------------------
001 p c 差(6),好(2),一般(4)
002 w e 差(8),好(7),一般(1)(所影响的行数为 2 行)create table b
(col varchar(20))insert b values ('a')
insert b values ('b')
insert b values ('c')
insert b values ('d')
insert b values ('e')
declare @sql varchar(1024)
set @sql=''
select @sql=@sql+b.col+',' from (select col from b) as b
set @sql='select '''+@sql+''''
exec(@sql)
a b
1 1
1 2
1 3
2 1
2 2
3 1
--如何转换成如下结果:
a b
1 1,2,3
2 1,2
3 1 create table tb
(
a int,
b int
)
insert into tb(a,b) values(1,1)
insert into tb(a,b) values(1,2)
insert into tb(a,b) values(1,3)
insert into tb(a,b) values(2,1)
insert into tb(a,b) values(2,2)
insert into tb(a,b) values(3,1)
goif object_id('pubs..f_hb') is not null
drop function f_hb
go--创建一个合并的函数
create function f_hb(@a int)
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',' + cast(b as varchar) from tb where a = @a
set @str = right(@str , len(@str) - 1)
return(@str)
End
go--调用自定义函数得到结果:
select distinct a ,dbo.f_hb(a) as b from tbdrop table tb--结果
a b
----------- ------
1 1,2,3
2 1,2
3 1(所影响的行数为 3 行)
多个前列的合并
数据的原始状态如下:
ID PR CON OP SC
001 p c 差 6
001 p c 好 2
001 p c 一般 4
002 w e 差 8
002 w e 好 7
002 w e 一般 1
===========================
用SQL语句实现,变成如下的数据
ID PR CON OPS
001 p c 差(6),好(2),一般(4)
002 w e 差(8),好(7),一般(1)if object_id('pubs..tb') is not null
drop table tb
gocreate table tb
(
id varchar(10),
pr varchar(10),
con varchar(10),
op varchar(10),
sc int
)
insert into tb(ID,PR,CON,OP,SC) values('001', 'p', 'c', '差', 6)
insert into tb(ID,PR,CON,OP,SC) values('001', 'p', 'c', '好', 2)
insert into tb(ID,PR,CON,OP,SC) values('001', 'p', 'c', '一般', 4)
insert into tb(ID,PR,CON,OP,SC) values('002', 'w', 'e', '差', 8)
insert into tb(ID,PR,CON,OP,SC) values('002', 'w', 'e', '好', 7)
insert into tb(ID,PR,CON,OP,SC) values('002', 'w', 'e', '一般', 1)
goif object_id('pubs..test') is not null
drop table test
go
select ID,PR,CON , OPS = op + '(' + cast(sc as varchar(10)) + ')' into test from tb--创建一个合并的函数
if object_id('pubs..f_hb') is not null
drop function f_hb
go
create function f_hb(@id varchar(10),@pr varchar(10),@con varchar(10))
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',' + cast(OPS as varchar) from test where id = @id and @pr = pr and @con = con
set @str = right(@str , len(@str) - 1)
return(@str)
End
go--调用自定义函数得到结果:
select distinct id ,pr , con , dbo.f_hb(id,pr,con) as OPS from testdrop table tb
drop table test--结果
id pr con OPS
---------- ---------- ---------- -------------------
001 p c 差(6),好(2),一般(4)
002 w e 差(8),好(7),一般(1)(所影响的行数为 2 行)create table b
(col varchar(20))insert b values ('a')
insert b values ('b')
insert b values ('c')
insert b values ('d')
insert b values ('e')
declare @sql varchar(1024)
set @sql=''
select @sql=@sql+b.col+',' from (select col from b) as b
set @sql='select '''+@sql+''''
exec(@sql)
create function fnMerge(@id varchar(10))
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',,' + strn from viewname where id = @id
return stuff(@str,1,2,'')
end
GO
----调用函数
select id,dbo.fnMerge(id) as strn from viewname group by id
drop view vTest
if object_id('fnMerge') is not null
drop function fnMerge
GO
create view vTest
as
select 'z01' as id,'asd' as strn union all
select 'z01' as id,'sdf' as strn union all
select 'z02' as id,'qwe' as strn union all
select 'z03' as id,'jkl' as strn union all
select 'z03' as id,'iop' as strn
GO
----创建函数
create function fnMerge(@id varchar(10))
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',,' + strn from vTest where id = @id
return stuff(@str,1,2,'')
end
GO
----调用函数
select id,dbo.fnMerge(id) as strn from vTest group by id----清除测试环境
drop view vTest
drop function fnMerge/*结果
id strn
---- ---------
z01 asd,,sdf
z02 qwe
z03 jkl,,iop
*/
2、用游标处理。
strn=CAST(MIN(strn) as varchar)
+CASE
WHEN COUNT(*)=1 THEN ''
ELSE ','+CAST(MAX(strn) as varchar)
END
FROM a17
GROUP BY id这个方法很好 2秒就搞定了
2、用游标处理。
--------------------------------------------------------
wangtiecheng说得不错,不过函数应该是首先
insert into T select 'z01','asd'
insert into T select 'z01','sdf'
insert into T select 'z02','qwe'
insert into T select 'z03','jkl'
insert into T select 'z04','iop'
SELECT id,
CAST(MIN(strn) as varchar(100)) +
CASE
WHEN COUNT(*)=1 THEN ''
ELSE ','+CAST(MAX(strn) as varchar(100))
END as strn
FROM T
GROUP BY id
drop table T