• select

    Random_String =

    substring(x,(abs(checksum(newid()))%36)+1,1)+

    substring(x,(abs(checksum(newid()))%36)+1,1)+

    substring(x,(abs(checksum(newid()))%36)+1,1)+

    substring(x,(abs(checksum(newid()))%36)+1,1)+

    /* and so on for as many characters as needed */

    substring(x,(abs(checksum(newid()))%36)+1,1)

    from

    (select x='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ') a

    Results:

    Random_String

    -------------

    T7TAR