Issue with mering ActiveRecord query results

Issue with mering ActiveRecord query results

class ABC
def self.active
self.live.where('starts_at <= ?', Time.now).where('(ends_at > ? || ends_at
IS NULL)', Time.now)
end
def self.recently_completed
self.completed.where("completed_at > ?", 2.days.ago)
end
The issue is when I do
(ABC.active + ABC.recently_completed).columns_hash This gives error,
undefined method `columns_hash' for #
When I do,
(ABC.active).merge(ABC.recently_completed) The query being run is actually
combination of the two. They are not run independently as I expected.
I need a way to write the code as to run the queries separately and then
merge the results but not as an array.