14 lines
361 B
Ruby
14 lines
361 B
Ruby
class AddParticipantCountToTopics < ActiveRecord::Migration[4.2]
|
|
def up
|
|
add_column :topics, :participant_count, :integer, default: 1
|
|
|
|
execute "UPDATE topics SET participant_count =
|
|
(SELECT COUNT(DISTINCT p.user_id) FROM posts AS p WHERE p.topic_id = topics.id)"
|
|
end
|
|
|
|
def down
|
|
remove_column :topics, :participant_count
|
|
end
|
|
|
|
end
|