Tracing Rails 3 SQL Queries

Tracing Rails 3 SQL queries

QueryTrace doesn't work as-is because many changes were made in Rails 3 esp in the area of ActiveRecord.

So, hacking around, I made it work like this:

You just need the 2 files below in the locations mentioned. Then restart the web server.
After the SQL, you should see Called from: in a console (magenta on white) and log file

In /vendor/plugins/query_trace/lib/query_trace.rb

module QueryTrace
  def self.append_features(klass)
    super
    klass.class_eval do
      unless method_defined?(:log_info_without_trace)
        alias_method :log_info_without_trace, :sql
        alias_method :sql, :log_info_with_trace
      end
    end
  end

  def log_info_with_trace(event)
    log_info_without_trace(event)
    logger.debug("\e[1m\e[35m\e[1m\e[47mCalled from:\e[0m " + clean_trace(caller[2..-2]).join("\n "))
  end

  def clean_trace(trace)
    Rails.respond_to?(:backtrace_cleaner) ?
      Rails.backtrace_cleaner.clean(trace) :
      trace
  end
end

In /vendor/plugins/query_trace/init.rb

require 'query_trace'

class ::ActiveRecord::LogSubscriber
  include QueryTrace
end

Tracing SQL queries created by Ruby-on-Rails

I think you're looking for QueryTrace.

Retrieving sql queries from Active-record queries in Rails 3

You can debug ActiveRecord queries from a console.

Hit rails console and enter:

ActiveRecord::Base.logger = Logger.new(STDOUT)

How to get the line of code that triggers a query?

I've found this solution:

module QueryTrace
  def self.enable!
    ::ActiveRecord::LogSubscriber.send(:include, self)
  end

  def self.append_features(klass)
    super
    klass.class_eval do
      unless method_defined?(:log_info_without_trace)
        alias_method :log_info_without_trace, :sql
        alias_method :sql, :log_info_with_trace
      end
    end
  end

  def log_info_with_trace(event)
    log_info_without_trace(event)
    trace_log = Rails.backtrace_cleaner.clean(caller).first
    if trace_log && event.payload[:name] != 'SCHEMA'
      logger.debug("   \\_ \e[33mCalled from:\e[0m " + trace_log)
    end
  end
end

In some initializer add QueryTrace.enable!

Show SQL ActiveRecord queries in rails console using SemanticLogger gem

It depends on the semantic_logger configuration but you should try

SemanticLogger.default_level = :trace

(you can run it in the console, and if works - add it to your initializers/development.rb or local.rb)

In my case I'd now see the output, but as a JSON:

> 2020-02-26 11:26:24.094050 D [2220:11016600] (220.0ms) ActiveRecord -- 
{ :sql => "SELECT COUNT(*) FROM \"things\"" }

So I need to add in my local.rb (not sure how this can be done dynamically in the console)

Rails.application.configure do
  config.rails_semantic_logger.semantic = false
end

to see

2020-02-26 11:31:34.972958 D [6280:14940580] ActiveRecord::Base --
    (198.6ms)  SELECT COUNT(*) FROM "things"

Log every SQL query to database in Rails

SQL logging in rails -
In brief - you need to override ActiveRecord execute method. There you can add any logic for logging.

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