mpakes

Keybase proof

I hereby claim:

• I am mpakes on github.
• I am mpakes (https://keybase.io/mpakes) on keybase.
• I have a public key whose fingerprint is A4D5 4452 8979 CEA0 1CA9 A939 AAB9 0D9A C8E7 4C82

To claim this, I am signing this object:

mpakes

# Credit to Mike Perham for this gem of an idea
# http://www.mikeperham.com/2007/12/17/creating-a-counter_cache-column/
class RailsMigration < ActiveRecord::Migration
  def self.up
    add_column :media, :followers_count, :integer, :default => 0, :null => false

    # Populate the media follower counter cache in one fell swoop.
    sql = "update media, (select operable_id, count(*) as the_count from follow_operations "\
      "group by operable_id) as follows set media.followers_count = follows.the_count "\
      "where media.id = follows.operable_id;"