Silence the Rails logger as well as the SQL logs

It's one thing to turn off logging in Rails, it's another to prevent SQL statements from appearing in your logs.

I've written a Rake helper to silence both. You can adapt it for other uses, but I think it's mostly relevant in Rake tasks.

# lib/rake_helpers.rb
module Rake
  module Helpers
    # Silence the Rails logger as well as the SQL logger
    # Call with a block e.g
    # silent { my block code }
    def silent
      ActiveRecord::ConnectionAdapters::AbstractAdapter.class_eval do
        alias_method :original_log_info, :log_info
        def silent_log_info(*args); end
        alias_method :log_info, :silent_log_info
      end
      @@old_logger = ActiveRecord::Base.logger
      ActiveRecord::Base.logger = Class.new { def method_missing(*args); end; }.new
      yield
      ActiveRecord::Base.logger = @@old_logger
      ActiveRecord::ConnectionAdapters::AbstractAdapter.class_eval do
        alias_method :log_info, :original_log_info
      end 
    end
  end
end

And sample usage:

# lib/tasks/db.rake
require 'rake_helpers'
include Rake::Helpers

namespace :db do
  namespace :update do

    desc "Update counter caches"
    task :counters => :environment do
      silent do
        ActiveRecord::Base.transaction do
          [Artist, Album].each do |model| 
            model.find_in_batches(:batch_size => 5000) do |batch|
              batch.each { |record| record.update_counts }
            end
          end
        end
      end
    end
  end
end