Disable Rails SQL logging in console

Question

Is there a way to disable SQL query logging when I'm executing commands in the console? Ideally, it would be great if I can just disable it and re-enable it with a command in the console.

I'm trying to debug something and using "puts" to print out some relevant data. However, the sql query output is making it hard to read.

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Edit: I found another solution, since setting the logger to nil sometimes raised an error, if something other than my code tried to call logger.warn

Instead of setting the logger to nil you can set the level of the logger to 1.

ActiveRecord::Base.logger.level = 1 # or Logger::INFO

Ommiad

since setting the logger to nil sometimes raised an error yap.. I got this one when trying to run rake db:migrate #1719712 – Lil

Confirming that this works in Rails 4.1.0 in an initializer. – Proscenium

Answer 1

To turn it off:

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

To turn it back on:

ActiveRecord::Base.logger = old_logger

Clare

Is there anywhere I can put this so I disable the SQL output permanently? I tried adding it to envs/dev.rb but not luck. – Decreasing

@samvermette, you don't set it. Just call it from the console before doing your work. – Kellyekellyn

you can put this code in .irbrc, which is basically .bashrc for the Rails console. in fact you can do just about anything in .irbrc if you want, e.g., syntax coloring, history, edit code in vi and then execute it in the Rails console, etc. check my gem utility_belt if you're on Ruby 1.8 or the Ruby 1.9 port called flyrb – Cymograph

@giles bowkett: Actually, .irbrcis like .bashrc but actually for your ruby interactive commandline. It's not a rails thing. I imagine you'd probably get errors if you tried to reference rails classes when you were running irb outside of a rails environment. – Skeet

@Decreasing you can it in a config file. For example: config/initializers/activerecord_logger.rb – Disinclined

Just fyi for anyone: after setting Base.logger, I also had to run ActiveRecord::Base.connection_pool.clear_reloadable_connections! – Manganese

ActiveRecord::Base.logger.level = 1 is a much better answer as it won't raise exceptions if you use .info and others. – Banking

I can't +1 this enough. I've came back to this answer so many time I wouldn't be able to count. For some reason I can't seem to remember the syntax correctly :) ... but the sure thing is that it's really helpful to have this answer, so thanks a lot @ryanbigg! – Fabaceous

@ryan-- hey is it possible to turn of logging for a specific model ? – Aleciaaleck

If you accidentaly ran this code (to turn it off) twice, thus also setting old_logger to nil, then you may create a new console logger with ActiveRecord::Base.logger = Logger.new(STDOUT) when you want to turn it back on again. – Nibble

dirty henry's approach is superior because if you have existing logger.debug statements they will all throw exceptions if you use the accepted answer – Roz

Answer 2

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

Ninos

Will work only for up to Rails 3: "DEPRECATION WARNING: silence is deprecated and will be removed from Rails 4.0" – Chasteen

@Chasteen I'm on rails 4.2 and silence seems to work fine – Pringle

@Chasteen I can also confirm this approach works just fine on Rails 4.2 – Overglaze

Works in Rails 5 and I see no warnings. This is the best answer IMO. – Imbrue

This doesn't work anymore (silence is not defined). Rails 5.2.2 – Vilhelmina

Works fine in Rails 6. Maybe it's just been moved around a bit? – Nore

Answer 3

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

Derwon

Odd, not for me, in Rails 3.0 or 3.1. Why would your Rails.logger be nil in an after_initialize block, did you do something else to customize your Rails init stack, or did you forget the config.after_initialize ? – Derwon

Works great in my Rails 3.1 app. Seemsl ike the nicest solution. +1 – Steak

Doesn't work for me ... sets the level OK in the after_initialize block, but the level is back to 0 by the time the console is open. Strange. (I'm using Pry as a console replacement, is that why?) – Heine

Answer 4

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

# /config/environments/development.rb

config.active_record.logger = nil

Phenobarbitone

That would only take effect in production, where logging is mostly surpressed anyway.... – Adah

in rails 5 this doesn't work. If you're work in linux environment, the following will work: config.active_record.logger = Logger.new('/dev/null') not sure if the same goes with newer version like 6 and 7 – Zymolysis

Answer 5

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

Keshiakesia

Good one. This works on SQL logging without affecting Rails.logger.debug statements. – Reliant

Total noob here. Where exactly should we put this? – Vins

I keep it in lib/monkeypatch.rb and have rails pull it in with the following line in config/application.rb: Dir.glob( "./lib/*.{rb}" ).each{ | file | require file }. Keep in mind that monkeypatching is frowned upon by some. Probably shouldn't check this into your production code. – Keshiakesia

I used this as a starting point for my Rails / ActiveRecord 6 solution, which I've added as an answer here. This version didn't quite work because it actually suppressed a lot of other logs I wanted to see. – Mockheroic

Answer 6

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.

Heinrike

I'm on rails 4.1.0 and it's worked fine for me. thanks – Talkathon

Thanks for mentioning this, if put config.log_level = :fatal it basically disables output to production log file almost completely, this is what I need since there is a custom request logger in play – Liu

Answer 7

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

Embosom

Answer 8

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.

Alphonse

Answer 9

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

Parasitology

Answer 10

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.

Mockheroic