A SQL Log Silencer

Posted by: on Jan 18, 2008 in Blog | Tags: , | One Comment

Here’s something I just whipped up to quiet ActiveRecord’s logging in development mode. Normally, ActiveRecord’s AbstractAdapter logs every SQL query as it is made. Sometimes, it’s nice to quiet this down without changing your log level while tracking down a problem.

class ActiveRecord::ConnectionAdapters::AbstractAdapter
  def log_info_with_silencing(sql, name, runtime)
    unless ActiveRecord::Base.silence_sql_logging
      log_info_without_silencing(sql, name, runtime)
    end
  end
 
  alias_method_chain :log_info, :silencing
end
 
module SqlSilencer
  def silence_sql
    logging = ActiveRecord::Base.silence_sql_logging
    begin
      ActiveRecord::Base.silence_sql_logging = true
      yield
    ensure
      ActiveRecord::Base.silence_sql_logging = logging
    end
  end
end
 
class ActiveRecord::Base
  @@silence_sql_logging = false
  cattr_accessor :silence_sql_logging
 
  include SqlSilencer
end
 
class ActionController::Base
  include SqlSilencer
end

Drop this into a file in config/initializers if you’re on Rails 2.0 or require it from within environment.rb for pre-2.0.

To use inside a controller action or model method, simply wrap the code you want to silence inside a block:

def index
  silence_sql do
    # lots of work here...
  end

One interesting side effect of this is that you can easily see how much database work is done as a result of what’s in your view. Wrap the entire controller action inside a silence_sql block, then look at your log. Any queries you see are a result of things you didn’t load in the controller.