分组字符合并SQL语句 按某字段合并字符串之一(简单合并)

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

create 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 id

drop function dbo.f_str

drop table tb

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, [value] = stuff((select ‘,’ + [value] from tb t where id = tb.id
for xml path(”)) , 1 , 1 , ”)from tb group by id

drop table tb

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_cursor
select * from @t
drop table tb