Disable Rails SQL logging in console

To turn it off:

old_logger = ActiveRecord::Base.logger
ActiveRecord::Base.logger = nil

To turn it back on:

ActiveRecord::Base.logger = old_logger

Here's a variation I consider somewhat cleaner, that still allows potential other logging from AR. In config/environments/development.rb :

config.after_initialize do
  ActiveRecord::Base.logger = Rails.logger.clone
  ActiveRecord::Base.logger.level = Logger::INFO
end

This might not be a suitable solution for the console, but Rails has a method for this problem: Logger#silence

ActiveRecord::Base.logger.silence do
  # the stuff you want to be silenced
end

For Rails 4 you can put the following in an environment file:

# /config/environments/development.rb

config.active_record.logger = nil

In case someone wants to actually knock out SQL statement logging (without changing logging level, and while keeping the logging from their AR models):

The line that writes to the log (in Rails 3.2.16, anyway) is the call to debug in lib/active_record/log_subscriber.rb:50.

That debug method is defined by ActiveSupport::LogSubscriber.

So we can knock out the logging by overwriting it like so:

module ActiveSupport
  class LogSubscriber
    def debug(*args, &block)
    end
  end
end

I used this: config.log_level = :info edit-in config/environments/performance.rb

Working great for me, rejecting SQL output, and show only rendering and important info.

In Rails 3.2 I'm doing something like this in config/environment/development.rb:

module MyApp
  class Application < Rails::Application
    console do
      ActiveRecord::Base.logger = Logger.new( Rails.root.join("log", "development.log") )
    end
  end
end

Just as an FYI, in Rails 2 you can do

ActiveRecord::Base.silence { <code you don't want to log goes here> }

Obviously the curly braces could be replaced with a do end block if you wanted.

I use activerecord 6.0.3.3 and I had to include ActiveSupport::LoggerSilence

include ActiveSupport::LoggerSilence

ActiveSupport::LoggerSilence.silence do
    ## everything you want to silence
end

This however did not work with anything related to creating or deleting SQL tables like ActiveRecord::Migration.drop_table. For this to be silenced I added:

ActiveRecord::Schema.verbose = false

I had to solve this for ActiveRecord 6, and I based my answer on fakeleft's response, but it wasn't quite right, since it was suppressing other logging such as the logging of nested views. What I did was created config/initializers/activerecord_logger.rb:

# Suppress SQL statement logging if necessary
# This is a dirty, dirty trick, but it works:
if ENV["ACTIVERECORD_HIDE_SQL"].present?
  module ActiveRecord
    class LogSubscriber
      def sql(event)
      end
    end
  end
end

The log subscriber in AR 6 has a sql event that we want to hide, so this is very narrowly targeted to skip that event.