SQL Server : How to test if a string has only digit characters

Question

I am working in SQL Server 2008. I am trying to test whether a string (varchar) has only digit characters (0-9). I know that the IS_NUMERIC function can give spurious results.

Answer 1

The selected answer does not work.

declare @str varchar(50)='79D136'

select 1 where @str NOT LIKE '%[^0-9]%'

I don't have a solution but know of this potential pitfall. The same goes if you substitute the letter 'D' for 'E' which is scientific notation.