不知道需要多少列呢？那我怎么动态写入

if OBJECT_ID('tb') is not null drop table tb
go
create table tb
(
   col1 varchar(10),
   col2 varchar(10),
   col3 varchar(10),
   col4 varchar(10),
   col5 varchar(10),
   col6 varchar(10),
   col7 varchar(10),
   col8 varchar(10)
)
declare @s varchar(100),@c int,@value varchar(8000)
set @c=(select COUNT(name) from syscolumns  where id=object_id('tb'))
set @value=replicate('''钉子'''+',',@c)
set @value=LEFT(@value,LEN(@value)-1)
print @value
select @s=isnull(@s+',','')+name from syscolumns  where id=object_id('tb')
print @s
exec('insert into tb('+@s+') select '+@value+'')

select * from tb