Creating Unique 10 Character Strings

A nice way to make a unique 10 character string is to generate a GUID, strip out the hypehens, and take only the left / right 10 characters as follows:

select right(replace(CONVERT(varchar(255), NEWID()), '-',''),10)

 This produces no duplicates over 1 million rows, when tested as follows:

create table #tmpID(ID varchar(10))

declare @i int

set @i = 1

while @i <1000000

begin

       insert into #tmpID

       select right(replace(CONVERT(varchar(255), NEWID()), '-',''),10)

       set @i = @i+1

end

select ID, count(*) [No of IDs]

from #tmpID

group by ID

having count(*) >1