求SQL函数或者SQL语句

[zhaokeke2004]

表里有2列(第一列是材料，第二列是用在什么项目上)，如：

comp project
fb A
fb B
fb C
fc B
fc D
fc E
fc F

要得到：

comp project
fb A,B,C
fc B,D,E,F

最好是函数，就是参数是fb, 函数返回A,B,C (逗号相隔)， 如果参数是fc, 将返回B,D,E,F

[还在加载中灬]

SELECT T.comp,STUFF((SELECT ','+project FROM TB WHERE T.comp=comp FOR XML PATH('')),1,1,'')project
FROM TB T
WHERE T.comp='fb'
GROUP BY comp

[中国风]

select  comp,project=stuff((select ','+project from TableA where comp=a.comp for xml path('')),1,1,'')
 from TableA as a
group by comp

[bw555]

参考

合并列值 
--*******************************************************************************************
表结构，数据如下： 
id    value 
----- ------ 
1    aa 
1    bb 
2    aaa 
2    bbb 
2    ccc 
 
需要得到结果： 
id    values 
------ ----------- 
1      aa,bb 
2      aaa,bbb,ccc 
即：group by id, 求 value 的和（字符串相加） 
 
1. 旧的解决方法(在sql server 2000中只能用函数解决。) 
--=============================================================================
create table tb(id int, value varchar(10)) 
insert into tb values(1, 'aa') 
insert into tb values(1, 'bb') 
insert into tb values(2, 'aaa') 
insert into tb values(2, 'bbb') 
insert into tb values(2, 'ccc') 
go 
--1. 创建处理函数 
CREATE FUNCTION dbo.f_strUnite(@id int) 
RETURNS varchar(8000) 
AS 
BEGIN 
    DECLARE @str varchar(8000) 
    SET @str = '' 
    SELECT @str = @str + ',' + value FROM tb WHERE id=@id 
    RETURN STUFF(@str, 1, 1, '') 
END 
GO 
-- 调用函数 
SELECt id, value = dbo.f_strUnite(id) FROM tb GROUP BY id 
drop table tb 
drop function dbo.f_strUnite 
go
/* 
id          value      
----------- ----------- 
1          aa,bb 
2          aaa,bbb,ccc 
（所影响的行数为 2 行） 
*/ 
--===================================================================================
2. 新的解决方法(在sql server 2005中用OUTER APPLY等解决。) 
create table tb(id int, value varchar(10)) 
insert into tb values(1, 'aa') 
insert into tb values(1, 'bb') 
insert into tb values(2, 'aaa') 
insert into tb values(2, 'bbb') 
insert into tb values(2, 'ccc') 
go 
-- 查询处理 
SELECT * FROM(SELECT DISTINCT id FROM tb)A OUTER APPLY( 
        SELECT [values]= STUFF(REPLACE(REPLACE( 
            ( 
                SELECT value FROM tb N 
                WHERE id = A.id 
                FOR XML AUTO 
            ), ' <N value="', ','), '"/>', ''), 1, 1, '') 
)N 
drop table tb 
 
/* 
id          values 
----------- ----------- 
1          aa,bb 
2          aaa,bbb,ccc 
 
(2 行受影响) 
*/ 
 
--SQL2005中的方法2 
create table tb(id int, value varchar(10)) 
insert into tb values(1, 'aa') 
insert into tb values(1, 'bb') 
insert into tb values(2, 'aaa') 
insert into tb values(2, 'bbb') 
insert into tb values(2, 'ccc') 
go 
 
select id, [values]=stuff((select ','+[value] from tb t where id=tb.id for xml path('')), 1, 1, '') 
from tb 
group by id 
 
/* 
id          values 
----------- -------------------- 
1          aa,bb 
2          aaa,bbb,ccc 
 
(2 row(s) affected) 
 
*/ 
 
drop table tb

[中国风]

if object_id('F_Str') is not null
    drop function F_Str
go
create function F_Str(@comp VARCHAR(50))
returns nvarchar(100)
as
begin
    declare @S nvarchar(100)
    select @S=isnull(@S+',','')+project from TableA where comp=@comp
    return @S
end
GO
SELECT DISTINCT comp,dbo.F_Str(comp) FROM  TableA

[chen357313771]

DECLARE @comp VARCHAR(20)
SET @comp='fb'
;WITH cte(comp,project) AS(
SELECT 'fb',	'A' UNION ALL
SELECT 'fb',	'B' UNION ALL
SELECT 'fb',	'C' UNION ALL
SELECT 'fc',	'B' UNION ALL
SELECT 'fc',	'D' UNION ALL
SELECT 'fc',	'E' UNION ALL
SELECT 'fc',	'F'
)
SELECT comp
	,STUFF((SELECT ','+project 
	FROM cte a 
	WHERE a.comp=b.comp 
	FOR XML PATH('')),1,1,'') 
FROM cte b
WHERE b.comp=@comp
GROUP BY b.comp

[Tiger_Zhao]

SELECT comp,
       project = Stuff((SELECT ','+project
                          FROM table1 AS b
                         WHERE b.comp = a.comp
                           for xml path('')),
                       1,1,'')
  FROM (SELECT DISTINCT comp FROM table1) AS a

comp project
---- ------------
fb   A,B,C
fc   B,D,E,F