Last Updated: May 18, 2017

Trace SQL queries back to Rails code

Based on a blog post by Ryan Bigg, throw the following into an initializer to trace SQL queries in your logs. The environment variable DEBUG_QUERIES is used to turn tracing on/off, whereas QUERY_TO_DEBUG contains the actual query you are looking for (will be interpolated into a regex):

if ENV['DEBUG_QUERIES']
 query_regex = /#{ENV['QUERY_TO_DEBUG']}/
 ActiveSupport::Notifications.subscribe('sql.active_record') do |_, _, _, _, details|
 if details[:sql] =~ query_regex
 puts '*' * 50
 puts details[:sql]
 puts caller.join("\n")
 puts '*' * 50
 end
 end
end

#ruby

#rails

#activerecord

#query

#trace