table 1
_______________id name
1 abctable 2
_________________
id parentid kmname
1 1 语文
2 1 数学我要查询的结果id name kmname
1 abc 语文,数学只允许用1条SQL语句。谢谢!
_______________id name
1 abctable 2
_________________
id parentid kmname
1 1 语文
2 1 数学我要查询的结果id name kmname
1 abc 语文,数学只允许用1条SQL语句。谢谢!
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 aa
1 bb
2 aaa
2 bbb
2 ccc
需要得到结果:
id value
------ -----------
1 aa,bb
2 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 int) returns varchar(100)
as
begin
declare @str varchar(1000)
set @str = ''
select @str = @str + ',' + cast(value as varchar) from tb where id = @id
set @str = right(@str , len(@str) - 1)
return @str
end
go--调用函数
select id , value = dbo.f_str(id) from tb group by iddrop function dbo.f_str
drop 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 tb
group 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')
go
declare @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 for
select id , value from tb
declare @id_old int , @id int , @value varchar(10) , @s varchar(100)
open my_cursor
fetch my_cursor into @id , @value
select @id_old = @id , @s=''
while @@FETCH_STATUS = 0
begin
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 , @value
END
insert @t values(@id_old , stuff(@s,1,1,''))
close my_cursor
deallocate my_cursorselect * from @t
drop table tb
sql 2005的语句.两种写法在1楼都有.
if object_id('[table1]') is not null drop table [table1]
go
create table [table1] (id int,name nvarchar(6))
insert into [table1]
select 1,'abc'
if object_id('[table2]') is not null drop table [table2]
go
create table [table2] (id int,parentid int,kmname nvarchar(4))
insert into [table2]
select 1,1,N'语文' union all
select 2,1,N'数学'
SELECT DISTINCT A.*,
kmname=STUFF((SELECT ','+kmname FROM [table2] WHERE parentid=B.parentid FOR XML PATH('')),1,1,'')
FROM [table2] B ,[table1] A
WHERE A.ID=B.parentid
/*
id name kmname.
----------- ------ --------
1 abc 语文,数学
*/
go
create table [table1] (id int,name nvarchar(6))
insert into [table1]
select 1,'abc'
if object_id('[table2]') is not null drop table [table2]
go
create table [table2] (id int,parentid int,kmname nvarchar(4))
insert into [table2]
select 1,1,N'语文' union all
select 2,1,N'数学'
select t1.id,t1.name,t2.kmname from [table1] t1 join
[table2] t2
on t1.id=t2.parentid
drop function FC_str
create function FC_str(@id int)
returns varchar(100)
as
begin
declare @str nvarchar(50)
set @str=''
select @str=@str+','+kmname from [table2] where parentid=@id
return stuff(@str,1,1,'')
end select distinct(t2.parentid) id,t1.name,dbo.FC_str(t2.parentid) kmname from [table2] t2
join [table1] t1
on t1.id=t2.parentidid name kmname
----------- ------ ----------------------------------------------------------------------------------------------------
1 abc 语文,数学(1 行受影响)
go
create table [table1] (id int,name nvarchar(6))
insert into [table1]
select 1,'abc'
if object_id('[table2]') is not null drop table [table2]
go
create table [table2] (id int,parentid int,kmname nvarchar(4))
insert into [table2]
select 1,1,N'语文' union all
select 2,1,N'数学'
select t1.id,t1.name,t2.kmname from [table1] t1 join
[table2] t2
on t1.id=t2.parentid
drop function FC_str
create function FC_str(@id int)
returns varchar(100)
as
begin
declare @str nvarchar(50)
set @str=''
select @str=@str+','+kmname from [table2] where parentid=@id
return stuff(@str,1,1,'')
end
--sql2000
select distinct(t2.parentid) id,
t1.name,
dbo.FC_str(t2.parentid) kmname
from [table2] t2
join [table1] t1
on t1.id=t2.parentid
--sql2005
select distinct(t2.parentid) id,
t1.name,
stuff((select ','+kmname from [table2] where parentid=t2.parentid for xml path('')),1,1,'')
from [table2] t2
join [table1] t1
on t1.id=t2.parentidid name kmname
----------- ------ ----------------------------------------------------------------------------------------------------
1 abc 语文,数学
go
create table [table1] (id int,name nvarchar(6))
insert into [table1]
select 1,'abc'
if object_id('[table2]') is not null drop table [table2]
go
create table [table2] (id int,parentid int,kmname nvarchar(4))
insert into [table2]
select 1,1,N'语文' union all
select 2,1,N'数学'
--sql2000
create function FC_str(@id int)
returns varchar(100)
as
begin
declare @str nvarchar(50)
set @str=''
select @str=@str+','+kmname from [table2] where parentid=@id
return stuff(@str,1,1,'')
end select distinct(t2.parentid) id,
t1.name,
dbo.FC_str(t2.parentid) kmname
from [table2] t2
join [table1] t1
on t1.id=t2.parentid
--sql2005
select distinct(t2.parentid) id,
t1.name,
stuff((select ','+kmname from [table2] where parentid=t2.parentid for xml path('')),1,1,'')
from [table2] t2
join [table1] t1
on t1.id=t2.parentid
if object_id('t2') is not null drop table t2
if object_Id('getkmname') is not null drop function getkmname
GOcreate table t1
(
id int,
name varchar(10)
)
insert into t1 select '1','abc' create table t2
(
id int,
parentid int,
kmname varchar(10)
)insert into t2select 1 , 1,'语文' union all
select 2, 1,'数学' GO
create function getkmname(@Id int)
returns varchar(100)
as
beginDeclare @temp varchar(100)SET @temp=''select @temp=@temp+','+kmnamefrom t2
where parentid=@Idreturn substring(@temp,2,Len(@temp)-1)endGO
select
a.id,max(a.name) as name,dbo.getkmname(a.id) as kmname from t1 a,t2 b where a.id=b.parentidgroup by a.id,b.parentId/*result*/id name kmname
----------- ---------- ----------------------------------------------------------------------------------------------------
1 abc 语文,数学(1 row(s) affected)
if object_Id('t1') is not null drop table t1
if object_id('t2') is not null drop table t2
GOcreate table t1
(
id int,
name varchar(10)
)
insert into t1 select '1','abc' create table t2
(
id int,
parentid int,
kmname varchar(10)
)insert into t2select 1 , 1,'语文' union all
select 2, 1,'数学' GOselect
a.id
,a.name
,STUFF((select ' , '+kmname from t2 b where a.id=b.parentid for xml path('')),1,3,'')
from t1 a
FROM [Table_2] T1
inner join [Table_2] T2 on T1.[parentid]=T2.[parentid]
left join [Table_1] T3 on T1.[parentid]=T3.[id]
where T1.[id]<>T2.[id]