How to strip all non-alphabetic characters from string in SQL Server?

Question

How could you remove all characters that are not alphabetic from a string?

What about non-alphanumeric?

Does this have to be a custom function or are there

Answer 1

I put this in both places where PatIndex is called.

PatIndex('%[^A-Za-z0-9]%', @Temp)

for the custom function above RemoveNonAlphaCharacters and renamed it RemoveNonAlphaNumericCharacters