我的表完整结构是这样的
id mname cname riqi
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} DN 电脑 2008-1-9
{10AE907E-72A0-4B9E-B768-9C9877A42658} XZT100 写字台 2008-3-6
{64DD0A9A-4174-47DC-896F-5CA6C7432EFC} DN100 电脑 2008-6-20
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} XZT 写字台 2008-6-2
{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2} JSJ 计算机 2008-4-20
{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2} C语言 2008-3-20 把这个表更新成如下表:
id mname cname riqi
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} DN,DN100 电脑 2008-1-9
{10AE907E-72A0-4B9E-B768-9C9877A42658} XZT100,XZT 写字台 2008-3-6
{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2} JSJ 计算机 2008-4-20
{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2} C语言 2008-3-20
刚问了,没有答案,大家给我一个答案,会给分的。
id mname cname riqi
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} DN 电脑 2008-1-9
{10AE907E-72A0-4B9E-B768-9C9877A42658} XZT100 写字台 2008-3-6
{64DD0A9A-4174-47DC-896F-5CA6C7432EFC} DN100 电脑 2008-6-20
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} XZT 写字台 2008-6-2
{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2} JSJ 计算机 2008-4-20
{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2} C语言 2008-3-20 把这个表更新成如下表:
id mname cname riqi
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} DN,DN100 电脑 2008-1-9
{10AE907E-72A0-4B9E-B768-9C9877A42658} XZT100,XZT 写字台 2008-3-6
{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2} JSJ 计算机 2008-4-20
{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2} C语言 2008-3-20
刚问了,没有答案,大家给我一个答案,会给分的。
--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
--*/
GODECLARE @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
----------- ----------------
1 aa,bb
2 aaa,bbb,ccc
合并分拆表_整理贴1
http://topic.csdn.net/u/20080612/22/c850499f-bce3-4877-82d5-af2357857872.html
if object_id('[TB]') is not null drop table [TB]
create table [TB] (id varchar(38),mname varchar(6),cname varchar(9),riqi datetime)
insert into [TB]
select '{68AC3023-7BA8-4F86-A806-91FC7A93BE57}','DN','电脑','2008-1-9' union all
select '{10AE907E-72A0-4B9E-B768-9C9877A42658}','XZT100','写字台','2008-3-6' union all
select '{64DD0A9A-4174-47DC-896F-5CA6C7432EFC}','DN100','电脑','2008-6-20' union all
select '{68AC3023-7BA8-4F86-A806-91FC7A93BE57}','XZT','写字台','2008-6-2' union all
select '{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2}','JSJ','计算机','2008-4-20' union all
select '{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2}','C语言','2008-3-20',nullselect id,dbo.fn_getname(id,0) as mname,dbo.fn_getname(id,1) as cname,riqi from [TB]
/*
----------------
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} DN,XZT 电脑,写字台 2008-01-09 00:00:00.000
{10AE907E-72A0-4B9E-B768-9C9877A42658} XZT100 写字台 2008-03-06 00:00:00.000
{64DD0A9A-4174-47DC-896F-5CA6C7432EFC} DN100 电脑 2008-06-20 00:00:00.000
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} DN,XZT 电脑,写字台 2008-06-02 00:00:00.000
{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2} JSJ 计算机 2008-04-20 00:00:00.000
{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2} C语言 2008-3-20 NULL
*/create function fn_getname(@str varchar(1000),@id int)
returns varchar(8000)
begin
declare @s varchar(8000) set @s=''
if @id=0
select @s=@s+mname+',' from tb where id=@str
else
select @s=@s+cname+',' from tb where id=@str
if len(@s)>0 set @s=left(@s,len(@s)-1)
return @s
end
if object_id('[TB]') is not null drop table [TB]
create table [TB] (id varchar(38),mname varchar(6),cname varchar(9),riqi datetime)
insert into [TB]
select '{68AC3023-7BA8-4F86-A806-91FC7A93BE57}','DN','电脑','2008-1-9' union all
select '{10AE907E-72A0-4B9E-B768-9C9877A42658}','XZT100','写字台','2008-3-6' union all
select '{64DD0A9A-4174-47DC-896F-5CA6C7432EFC}','DN100','电脑','2008-6-20' union all
select '{68AC3023-7BA8-4F86-A806-91FC7A93BE57}','XZT','写字台','2008-6-2' union all
select '{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2}','JSJ','计算机','2008-4-20' union all
select '{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2}','C语言','2008-3-20',nullselect id,dbo.fn_getname(id,0) as mname,dbo.fn_getname(id,1) as cname,min(riqi) as riqi from [TB] group by id
/*
----------------
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} DN,XZT 电脑,写字台 2008-01-09 00:00:00.000
{64DD0A9A-4174-47DC-896F-5CA6C7432EFC} DN100 电脑 2008-06-20 00:00:00.000
{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2} C语言 2008-3-20 NULL
{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2} JSJ 计算机 2008-04-20 00:00:00.000
{10AE907E-72A0-4B9E-B768-9C9877A42658} XZT100 写字台 2008-03-06 00:00:00.000
*/create function fn_getname(@str varchar(1000),@id int)
returns varchar(8000)
begin
declare @s varchar(8000) set @s=''
if @id=0
select @s=@s+isnull(mname,'')+',' from tb where id=@str
else
select @s=@s+isnull(cname,'')+',' from tb where id=@str
if len(@s)>0 set @s=left(@s,len(@s)-1)
return @s
end
--> 测试数据: [TB]
if object_id('[TB]') is not null drop table [TB]
create table [TB] (id varchar(38),mname varchar(6),cname varchar(9),riqi datetime)
insert into [TB]
select '{68AC3023-7BA8-4F86-A806-91FC7A93BE57}','DN','电脑','2008-1-9' union all
select '{10AE907E-72A0-4B9E-B768-9C9877A42658}','XZT100','写字台','2008-3-6' union all
select '{64DD0A9A-4174-47DC-896F-5CA6C7432EFC}','DN100','电脑','2008-6-20' union all
select '{68AC3023-7BA8-4F86-A806-91FC7A93BE57}','XZT','写字台','2008-6-2' union all
select '{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2}','JSJ','计算机','2008-4-20' union all
select '{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2}','','C语言','2008-3-20'select (select top 1 id from [tb] where riqi=min(a.riqi) and cname=a.cname) as id,
dbo.fn_getname2(cname) as mname,cname,min(riqi) as riqi from [TB] a group by cname
order by min(riqi) /*
----------------
{68AC3023-7BA8-4F86-A806-91FC7A93BE57} DN,DN100 电脑 2008-01-09 00:00:00.000
{10AE907E-72A0-4B9E-B768-9C9877A42658} XZT100,XZT 写字台 2008-03-06 00:00:00.000
{502D2591-72F1-4C9D-AE67-B58C0FCE6EA2} C语言 2008-03-20 00:00:00.000
{402D2590-72F1-4C9D-AE67-B58C0FCE6EA2} JSJ 计算机 2008-04-20 00:00:00.000
*/create function fn_getname2(@str varchar(1000))
returns varchar(8000)
begin
declare @s varchar(8000) set @s=''
select @s=@s+isnull(mname,'')+',' from tb where cname=@str
if len(@s)>0 set @s=left(@s,len(@s)-1)
return @s
end
不用函数也可以的select a.id,a.mname+isnull(', '+b.mname,'')mname,a.cname,a.riqi from #T a
left join #T b on a.cname=b.cname and a.riqi<b.riqi
inner join (select cname ,min(riqi) riqi
from #T group by cname) bb on a.cname=bb.cname and a.riqi=bb.riqi
order by riqi