sql语句问题

[wnba1983]

sql求解
表a
列 a1 a2
记录 1 a
1 b
2 x
2 y
2 z
用select能选成以下结果吗？
1 ab
2 xyz

[feixianxxx]

select a1,
a2=stuff((select ''+a2 from a where j.a1=a1 for xml path('')),1,1,'')
from a j

[SQL77]

字符合并函数,
05XML

[Rotel-刘志东]

你的意思是不是两列合并一列呀！

[SQL77]

CREATE FUNCTION GET_NUM(@A1 INT)
RETURNS NVARCHAR(500)
AS 
  DECLARE @A2 NVARCHAR(500)
  SELECT @A2=ISNULL(@A2,'')+A2 FROM TB WHERE A1=@A1
  RETURN @A2

[wnba1983]

1楼的答案我完全看不懂，能否解释下

[SQL77]

[Quote=引用 5 楼 wnba1983 的回复:]
1楼的答案我完全看不懂，能否解释下

[/Quote]
是2005的

[qiqi860819]

create table mytest
(
id int,
[value] varchar(8)
)
go

insert into mytest
select 1,'a' union all
select 1,'b' union all
select 2,'x' union all
select 2,'y' union all
select 2,'z'
go

create function fun_test(@id int)
returns varchar(1000)
as
begin
declare @str varchar(1000)
set @str='';
select @str=@str+[value] from mytest where id=@id
return @str
end

select id,dbo.fun_test(id) from mytest group by id

[daiyueqiang2045]

[Quote=引用 7 楼 qiqi860819 的回复:]
SQL codecreatetable mytest
(
idint,[value]varchar(8)
)goinsertinto mytestselect1,'a'unionallselect1,'b'unionallselect2,'x'unionallselect2,'y'unionallselect2,'z'gocreatefunction fun_test(@idint)returns?-
[/Quote]
加上了列名
select id,dbo.GetValue(id) [values] from mytest group by id

[--小F--]

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 

[cxmcxm]

按照7,9楼的,
创建自定义函数,再用group by 查询

[fhjzgsy]

顶个