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SQL 简单有关问题

热度:79   发布时间:2016-04-27 14:17:32.0
SQL 简单问题
create table test
(
id int,
tName varchar(50)
)
drop table test
insert into test values(1,'ggg')
insert into test values(1,'ddd')
insert into test values(1,'hhh')
insert into test values(1,'yyy')
insert into test values(1,'uuu')

select * from test
-------------输出结果: ---
id tName
1 ggg
1 ddd
1 hhh
1 yyy
1 uuu


-------但我想要的结果是: ----
id tName
1 ggg,ddd,hhh,yyy,uuu


求查询语句 ? 谢谢!




------解决方案--------------------
SQL code
/*标题:按某字段合并字符串之一(简单合并)作者:爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开)时间:2008-11-06地点:广东深圳描述:将如下形式的数据按id字段合并value字段。id    value----- ------1     aa1     bb2     aaa2     bbb2     ccc需要得到结果:id     value------ -----------1      aa,bb2      aaa,bbb,ccc即:group by id, 求 value 的和(字符串相加)*/--1、sql2000中只能用自定义的函数解决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')gocreate function dbo.f_str(@id varchar(10)) returns varchar(1000)asbegin  declare @str varchar(1000)  select @str = isnull(@str + ',' , '') + cast(value as varchar) from tb where id = @id  return @strendgo--调用函数select id , value = dbo.f_str(id) from tb group by iddrop function dbo.f_strdrop table tb--2、sql2005中的方法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')goselect id, [value] = stuff((select ',' + [value] from tb t where id = tb.id for xml path('')) , 1 , 1 , '')from tbgroup by iddrop table tb--3、使用游标合并数据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')godeclare @t table(id int,value varchar(100))--定义结果集表变量--定义游标并进行合并处理declare my_cursor cursor local forselect id , value from tbdeclare @id_old int , @id int , @value varchar(10) , @s varchar(100)open my_cursorfetch my_cursor into @id , @valueselect @id_old = @id , @s=''while @@FETCH_STATUS = 0begin    if @id = @id_old       select @s = @s + ',' + cast(@value as varchar)    else      begin        insert @t values(@id_old , stuff(@s,1,1,''))        select @s = ',' + cast(@value as varchar) , @id_old = @id      end    fetch my_cursor into @id , @valueENDinsert @t values(@id_old , stuff(@s,1,1,''))close my_cursordeallocate my_cursorselect * from @tdrop table tb
------解决方案--------------------
SELECT ID,
STUFF((SELECT ','+tName FROM test WHERE ID=a.ID FOR XML PATH('')),1,1,'') AS tName
FROM test AS a
GROUP BY ID
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