Your current regex requires the string to consist entirely of numbers. Try the following:
where regexp_like( AIssue, '^[[:digit:]].*$' )
(pay attention to the added point).
To develop,. matches any character, and *
means "repeat the previous term zero or more times."
Thus, the original regular expression says “zero or more digits”, while the above expression says “digit, followed by zero or more of any characters.
edit . A shorter version of the above regex was suggested by @mellamokb in the comments:
where regexp_like( AIssue, '^[[:digit:]]' )
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