Sql排序 - MS-SQL Server / 基础类

我的Tblworkbill表的数据如下:

id workbillno ..................
1 1
2 6
3 a1
4 c2
5 2
6 aa
7 a2
8 5
9 7
10 d3
11 b1
. .
. .
. .
. .

如何将workbillno排序为:
1
2
5
6
7
a1
a2
b1
c2
d3
aa

---

SQL code:

--> 测试数据：[TB]
if object_id('[TB]') is not null drop table [TB]
create table [TB]([id] int,[workbillno] varchar(2))
insert [TB]
select 1,'1' union all
select 2,'6' union all
select 3,'a1' union all
select 4,'c2' union all
select 5,'2' union all
select 6,'aa' union all
select 7,'a2' union all
select 8,'5' union all
select 9,'7' union all
select 10,'d3' union all
select 11,'b1'


create function dbo.f_ASCII(@s varchar(50)) returns int
as
begin
declare @i int
set @i=0
while len(@s)>0
begin
set @i=@i+ASCII(left(@s,1))
set @s=right(@s,len(@s)-1)
end
return @i
end
go

select * from TB order by dbo.f_ASCII(workbillno)

/*
id workbillno
----------- ----------
1 1
5 2
8 5
2 6