Another variation from Lynn's version:

;with

a1 as (

select 1 as N union all select 1 union all select 1 union all select 1 union all

select 1 union all select 1 union all select 1 union all select 1

),

cteRandomString as (

select

substring('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ',(abs(checksum(newid()))%36)+1,1)

as RandomString

from

( select 1 as N from a1 as a cross join a1 as b ) a

)

select

convert(varchar(64),replace((

select

','+RandomString

from

cteRandomString

for xml path (''))

,',','')) as RandomString;