select p.person_id, p.lname, p.fname, p.direct_phone, p.active, o.org_name, sq.* from people as p join organizations as o on p.org_id = o.org_id cross join lateral (select a.next_contact from activities as a where a.person_id = p.person_id and p.active='True' and a.next_contact is not null order by a.next_contact DESC limit 1) sq;
It works wellm, but the row order is not that of a.next_contact. In fact, there seems to be no order in the returned set.
The next_contact column is in the lateral sub-query. Does this make a difference?
Yes, if you join the result on an ordered subquery to anything you no longer have a guaranteed order for the combined relation.