怎么使SQL中的字符串字段实现自增

1 create table Test
2 (
3 id int identity(1,1) primary key,
4 olid varchar(8),
5 [name] varchar(255),
6 [time] datetime
7 )
8 set nocount on
9 declare @count int;
10 declare @olid varchar(255);
11 set @count = 1;
12 set @olid = '1';
13 while(@count < 10)
14 begin
15 insert into Test values(@olid,'cc','2008-1-7 17:17:21')
16 set @count = @count + 1
17 set @olid = str(@olid) + 1
18 end