Add comment functionality to tracks

db/migrate/20190720062321_add_comments_count_to_tracks.rb

@@ -0,0 +1,10 @@
+class AddCommentsCountToTracks < ActiveRecord::Migration[5.1]
+  def change
+    add_column :tracks, :comments_count, :integer, default: 0, null: false
+
+    Track.find_each do |track|
+      comments_count = track.comment_threads.count
+      track.update_attributes(:comments_count, comments_count) unless comments_count.zero?
+    end
+  end
+end