MYSQL Concat not working

Question

UPDATE profile SET favourties=CONCAT(favourties,"123") WHERE id=1

i want to append 123 in favourties but if default value of favourties is set to NULL then this query will not work. What will be query if favourties is set to NULL and then append 123 with it

Answer 1

UPDATE profile SET favourties=CONCAT(IFNULL(favourties, ''),"123") WHERE id=1

Answer 2

Wrap the field around with the COALESCE function:

UPDATE profile
SET favourties = CONCAT(COALESCE(favourties, ''),"123")
WHERE id=1