MySQL - Select only non - numeric values from varchar column

The REGEXP '^[^0-9]+$' selects all non numeric characters

SELECT state
FROM `enquiry`
GROUP BY state
HAVING state REGEXP '^[^0-9]+$'

The regex [a-zA-Z] should only fire true if a value contains at least one letter.

SELECT * 
FROM mixedvalues 
WHERE value REGEXP '[a-zA-Z]';   -- or REGEXP '[[:alpha:]]'