I want to select all rows, which are numbers and commas, nothing else.
For example these varchars should be returned by select:
If I understand correctly:
where col not like '%[^,0-9]%'
If you want to prevent two commas from being in a row:
where col not like '%[^,0-9]%' and col not like '%,,%'
I feel the need to add that storing numbers in comma-delimited lists is a really bad idea.