如果将触发器更改为BEFORE而不是AFTER，则可以这样操作:

If you change your trigger to BEFORE instead of AFTER you could do it like this:

CREATE TRIGGER upd_total_votes BEFORE UPDATE ON products_score 
FOR EACH ROW 
BEGIN
    SET new.votes_total = new.votes_1 + new.votes_2 + new.votes_3 + new.votes_4 + new.votes_5 
END
;