SQL取每一条记录的问题

SQL code问题描述：
无论是在sql 2000，还是在 sql 2005 中,都没有提供字符串的聚合函数，
  所以，当我们在处理下列要求时，会比较麻烦：
有表tb, 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-- 1. 创建处理函数
CREATE FUNCTION dbo.f_str(@id int)
RETURNS varchar(8000)
AS
BEGIN
    DECLARE @r varchar(8000)
    SET @r = ''
    SELECT @r = @r + ',' + value
    FROM tb
    WHERE id=@id
    RETURN STUFF(@r, 1, 1, '')
END
GO
-- 调用函数SELECt id, values=dbo.f_str(id)
FROM tb
GROUP BY id-- 2. 新的解决方法
-- 示例数据
DECLARE @t TABLE(id int, value varchar(10))
INSERT @t SELECT 1, 'aa'
UNION ALL SELECT 1, 'bb'
UNION ALL SELECT 2, 'aaa'
UNION ALL SELECT 2, 'bbb'
UNION ALL SELECT 2, 'ccc'-- 查询处理
SELECT *
FROM(
    SELECT DISTINCT
        id
    FROM @t
)A
OUTER APPLY(
    SELECT
        [values]= STUFF(REPLACE(REPLACE(
            (
                SELECT value FROM @t N
                WHERE id = A.id
                FOR XML AUTO
            ), '<N value="', ','), '"/>', ''), 1, 1, '')
)N/*--结果
id          values
----------- ----------------
1           aa,bb
2           aaa,bbb,ccc
(2 行受影响)
--*/--各种字符串分函数--3.3.1 使用游标法进行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--合并处理
--定义结果集表变量
DECLARE @t TABLE(col1 varchar(10),col2 varchar(100))--定义游标并进行合并处理
DECLARE tb CURSOR LOCAL
FOR
SELECT col1,col2 FROM tb ORDER BY  col1,col2
DECLARE @col1_old varchar(10),@col1 varchar(10),@col2 int,@s varchar(100)
OPEN tb
FETCH tb INTO @col1,@col2
SELECT @col1_old=@col1,@s=''
WHILE @@FETCH_STATUS=0
BEGIN
    IF @col1=@col1_old
        SELECT @s=@s+','+CAST(@col2 as varchar)
    ELSE
    BEGIN
        INSERT @t VALUES(@col1_old,STUFF(@s,1,1,''))
        SELECT @s=','+CAST(@col2 as varchar),@col1_old=@col1
    END
    FETCH tb INTO @col1,@col2
END
INSERT @t VALUES(@col1_old,STUFF(@s,1,1,''))
CLOSE tb
DEALLOCATE tb
--显示结果并删除测试数据
SELECT * FROM @t
DROP TABLE tb
/*--结果
col1       col2
---------- -----------
a          1,2
b          1,2,3
--*/
GO
/*==============================================*/
--3.3.2 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/*==============================================*/
--3.3.3 使用临时表实现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--合并处理
SELECT col1,col2=CAST(col2 as varchar(100))
INTO #t FROM tb
ORDER BY col1,col2
DECLARE @col1 varchar(10),@col2 varchar(100)
UPDATE #t SET
    @col2=CASE WHEN @col1=col1 THEN @col2+','+col2 ELSE col2 END,
    @col1=col1,
    col2=@col2
SELECT * FROM #t
/*--更新处理后的临时表
col1       col2
---------- -------------
a          1
a          1,2
b          1
b          1,2
b          1,2,3
--*/
--得到最终结果
SELECT col1,col2=MAX(col2) FROM #t GROUP BY col1
/*--结果
col1       col2
---------- -----------
a          1,2
b          1,2,3
--*/
--删除测试
DROP TABLE tb,#t
GO
/*==============================================*/--3.3.4.1 每组 <=2 条记录的合并
--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 'c',3--合并处理
SELECT col1,
    col2=CAST(MIN(col2) as varchar)
        +CASE
            WHEN COUNT(*)=1 THEN ''
            ELSE ','+CAST(MAX(col2) as varchar)
        END
FROM tb
GROUP BY col1
DROP TABLE tb
/*--结果
col1       col2
---------- ----------
a          1,2
b          1,2
c          3
--*/--3.3.4.2 每组 <=3 条记录的合并
--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
UNION ALL SELECT 'c',3--合并处理
SELECT col1,
    col2=CAST(MIN(col2) as varchar)
        +CASE
            WHEN COUNT(*)=3 THEN ','
                +CAST((SELECT col2 FROM tb WHERE col1=a.col1 AND col2 NOT IN(MAX(a.col2),MIN(a.col2))) as varchar)
            ELSE ''
        END
        +CASE
            WHEN COUNT(*)>=2 THEN ','+CAST(MAX(col2) as varchar)
            ELSE ''
        END
FROM tb a
GROUP BY col1
DROP TABLE tb
/*--结果
col1       col2
---------- ------------
a          1,2
b          1,2,3
c          3
--*/
GO
if not object_id('A') is null
    drop table A
Go
Create table A([id] int,[cname] nvarchar(2))
Insert A
select 1,N'张三' union all
select 2,N'李四' union all
select 3,N'王五' union all
select 4,N'蔡六'
Go
--> -->

if not object_id('B') is null
    drop table B
Go
Create table B([id] int,[cname] nvarchar(5))
Insert B
select 1,N'1,2,3' union all
select 2,N'3,4'
Go
create function F_str(@cname nvarchar(100))
returns nvarchar(100)
as
begin
select @cname=replace(@cname,ID,[cname]) from A where patindex('%,'+rtrim(ID)+',%',','+@cname+',')>0
return @cname
end
go
select [id],dbo.F_str([cname])[cname] from Bid          cname
----------- ----------------------------------------------------------------------------------------------------
1           张三,李四,王五
2           王五,蔡六(2 個資料列受到影響)

DECLARE @TB TABLE(COL NVARCHAR(20), COL2 NVARCHAR(5))
INSERT @TB
SELECT '2008112500000031',  N'新测试1' UNION ALL
SELECT '2008112500000031',  N'新测试2' UNION ALL
SELECT '2008112500000031',  N'新测试3'DECLARE @STR NVARCHAR(4000)
SET @STR=N''
SELECT @STR=@STR+COL+N' '+COL2 FROM @TBSELECT @STR
/*
2008112500000031 新测试12008112500000031 新测试22008112500000031 新测试3
*/

select row_number() over(order by a),a from table

declare @s varchar(8000)
set @s=''
select @s=@s+isnull(col1,'')+' '+isnull(col2,'') from 表
print @s

如果用TOP呢？现在能取到第一行和最后一行，中间的能取吗？

create table #aaa(a varchar(100), b varchar(10))insert #aaa values('2008112500000031', '新测试1')
insert #aaa values('2008112500000031', '新测试2')
insert #aaa values('2008112500000031', '新测试3')declare @sql varchar(1000)
select @sql = ''select @sql = @sql + ' ' + a + ' ' +b from #aaaselect @sqldrop table #aaa

create table #aaa(a varchar(100), b varchar(10)) insert #aaa values('2008112500000031', '新测试1')
insert #aaa values('2008112500000031', '新测试2')
insert #aaa values('2008112500000031', '新测试3') declare @sql varchar(1000)
select @sql = '' select @sql = @sql + ' ' + a + ' ' +b from #aaa select @sql drop table #aaa

if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([id] varchar(17),[name] varchar(7))
insert [tb]
select '2008112500000031','新测试1' union all
select '2008112500000031','新测试2' union all
select '2008112500000031','新测试3' union all
select '2008112500000031','新测试4' union all
select '2008112500000031','新测试5' union all
select '2008112500000031','新测试6'--select * from [tb]select iid=identity(int,1,1),* into # from tb
--取第二条到第四条
declare @s nvarchar(4000)
select @s=isnull(@s+' ','')+rtrim(id)+' '+[name]
from #
where iid between 2 and 4
select @s
--测试结果:
/*
2008112500000031 新测试2 2008112500000031 新测试3 2008112500000031 新测试4
*/

declare @str varchar(8000)
set @str=''
select @str=@str+字段1+字段2 from 表
select @str

SELECT TOP 1 * FROM AffairAll aa WHERE aa.Part NOT IN (
SELECT a.Part,a.PartAffair,a.YORN,a.Result,b.Part, b.PartAffair, b.YORN, b.Result
FROM (SELECT TOP 1 * FROM AffairAll aa WHERE aa.AffairNum='2008112500000031' ORDER BY aa.Part DESC) a,
(SELECT TOP 1 * FROM AffairAll aa WHERE aa.AffairNum='2008112500000031' ORDER BY aa.Part) b)
这种方法错在哪了？
错误提示：Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.

调试易

SQL取每一条记录的问题

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