sql 增加自增涨序号

declare @str  varchar(2000)
declare @i int
set @i = 1
set @str=''

SELECT @str=@str+cast((@i+1) as CHAR(1))+isnull(tm.sAnswer,'')
FROM tbAnswer t
left outer join dbo.tbPollMyAnswer tm on tm.iAnswerId=t.iAnswerId
WHERE t.iQuestionID=12 and tm.sAnswer is not null
print @str

如上
想加一个 序号，1，2，3，4......
大神们给点指点

[解决办法]

declare @str  varchar(2000)
declare @i int
set @i = 1
set @str=''
 
SELECT @str=@str+cast((@i+1) as CHAR(1))+isnull(tm.sAnswer,''),num=rownumber()over(order by getdate())
FROM tbAnswer t
left outer join dbo.tbPollMyAnswer tm on tm.iAnswerId=t.iAnswerId
WHERE t.iQuestionID=12 and tm.sAnswer is not null
print @str

[解决办法]
num=rownumber()over(order by getdate())