REGEX match for numeric value OR null value

Hi all,

I’m very new to REGEX. I’m trying to filter out rows based on if a column (string) matches a numeric value or is null.

Based on some googling, I’ve tried:

^\d.?\d$|^null$

^\d.?\d$|^\w$

In both cases, the null values end up not being included in the match. Any suggestions on what I’m doing wrong?

Cheers,

David.