SQL having clause question...

# Person has_many cards has_many transaction_feeds.
# I would like to find all of the people with at least one transaction feed with the is_ach bool set to true:
SELECT DISTINCT(people.id) AS person_id FROM `people`
  INNER JOIN `cards` ON cards.person_id = people.id
  INNER JOIN `transaction_feeds` ON transaction_feeds.card_id = cards.id
  WHERE (transaction_feeds.is_ach = 1)
  GROUP BY person_id
  HAVING COUNT(transaction_feeds.id) > 0;

# This works.

# I would like to find all of the people with no transaction feeds that have that is_ach bool set to true.
# I don't know how to do this.

# NAIVE ATTEMPT ONE:
SELECT DISTINCT(people.id) AS people_id FROM `people`
  INNER JOIN `cards` ON cards.person_id = people.id
  LEFT JOIN `transaction_feeds` ON transaction_feeds.card_id = cards.id
  WHERE (transaction_feeds.is_ach = 1)
  GROUP BY person_id
  HAVING COUNT(transaction_feeds.id) = 0;
Empty set (0.42 sec)

# To clarify, and for _raymond_...
# I am attempting to write a query that will find all people that do not have any associated 
# transaction_feeds with the is_ach bool set to true.  That is, either people with NO 
# transaction_feeds, or people with only non-ach transaction_feeds.  If a person has a single 
# transaction_feed with that bool set, they should not show up in the set for the query I'm 
# attempting to write.  That is all.