参照: 使用用户定义函数,配合SELECT处理完成字符串合并处理的示例 --处理的数据 CREATE TABLE tb(col1 varchar(10),col2 int) INSERT tb SELECT 'a',1 UNION ALL SELECT 'a',2 UNION ALL SELECT 'b',1 UNION ALL SELECT 'b',2 UNION ALL SELECT 'b',3 GO--合并处理函数 CREATE FUNCTION dbo.f_str(@col1 varchar(10)) RETURNS varchar(100) AS BEGIN DECLARE @re varchar(100) SET @re='' SELECT @re=@re+','+CAST(col2 as varchar) FROM tb WHERE col1=@col1 RETURN(STUFF(@re,1,1,'')) END GO--调用函数 SELECT col1,col2=dbo.f_str(col1) FROM tb GROUP BY col1 --删除测试 DROP TABLE tb DROP FUNCTION f_str /*--结果 col1 col2 ---------- ----------- a 1,2 b 1,2,3 --*/ GO
create table testa(Field_A int,Field_B char(1)) insert into testa select 1,'A' union all select 1,'B' union all select 2,'C' union all select 2,'D' union all select 2,'E' union all select 3,'F' union all select 4,'G' union all select 1,'H'create function f_testa(@a int) returns varchar(255) as begin declare @s varchar(255) set @s='' select @s=@s+Field_B+',' from testa where Field_A=@a return left(@s,len(@s)-1) endselect Field_A,dbo.f_testa(Field_A) as Field_B from testa group by Field_A
create table testa(Field_A int,Field_B char(1)) insert into testa select 1,'A' union all select 1,'B' union all select 2,'C' union all select 2,'D' union all select 2,'E' union all select 3,'F' union all select 4,'G' union all select 1,'H'create function f_testa(@id int) returns varchar(255) as begin declare @s varchar(255) set @s='' select @s=@s+','+Field_B from testa where Field_A=@id select @s = stuff(@s,1,1,'') return @s endselect Field_A,dbo.f_testa(Field_A) as Field_B from testa group by Field_A
--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)
使用用户定义函数,配合SELECT处理完成字符串合并处理的示例
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3
GO--合并处理函数
CREATE FUNCTION dbo.f_str(@col1 varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+CAST(col2 as varchar)
FROM tb
WHERE col1=@col1
RETURN(STUFF(@re,1,1,''))
END
GO--调用函数
SELECT col1,col2=dbo.f_str(col1) FROM tb GROUP BY col1
--删除测试
DROP TABLE tb
DROP FUNCTION f_str
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
GO
insert into testa
select 1,'A'
union all select 1,'B'
union all select 2,'C'
union all select 2,'D'
union all select 2,'E'
union all select 3,'F'
union all select 4,'G'
union all select 1,'H'create function f_testa(@a int)
returns varchar(255)
as
begin
declare @s varchar(255)
set @s=''
select @s=@s+Field_B+',' from testa where Field_A=@a
return left(@s,len(@s)-1)
endselect Field_A,dbo.f_testa(Field_A) as Field_B from testa group by Field_A
insert into testa
select 1,'A'
union all select 1,'B'
union all select 2,'C'
union all select 2,'D'
union all select 2,'E'
union all select 3,'F'
union all select 4,'G'
union all select 1,'H'create function f_testa(@id int)
returns varchar(255)
as
begin
declare @s varchar(255)
set @s=''
select @s=@s+','+Field_B from testa where Field_A=@id
select @s = stuff(@s,1,1,'')
return @s
endselect Field_A,dbo.f_testa(Field_A) as Field_B from testa group by Field_A
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)