Question

As a follow up from this post: i am trying to log all queries that are being generated. I have tried placing this in an initializer, and also just straight up running it in console and execute never seems to get executed.

I have tried the following:

connection = ActiveRecord::Base.connection
class << connection
  alias :original_exec :execute
  def execute(sql, *name)
    # try to log sql command but ignore any errors that occur in this block
    # we log before executing, in case the execution raises an error
    raise "THROW AN ERROR"
    begin
        file = File.open(RAILS_ROOT + "/log/sql.txt",'a'){|f| f.puts Time.now.to_s+": "+sql}
    rescue Exception => e
      ;
    end
    # execute original statement
    original_exec(sql, *name)
  end
end

And then run

Person.last

And I still get no error.

Answer 1

You don’t need to monkey-patch ActiveRecord to get logging (which you’re doing incorrectly here anyway). I assume you want this in production, since in development all queries are already logged. Simply set this in config/environments/production.rb:

config.log_level = :debug

Or if you want to restrict this to SQL queries only, without the other verbosity, try this:

ActiveRecord::Base.logger.level = Logger::DEBUG

Or if your goal is to write the SQL queries to a dedicated logfile, check out this question: Rails3 SQL logging output in a separate file