How to show SQL query log generated by a RSpec test?

Question

I am writing a spec for my rails 3 application. I want to test that db transactions are really working. It would be really helpful to be able to see the sql queries being generated my app while being driven by the spec.

Is there a way to see the queries just like in the rails console?

I'm using Rails 3.0.9, RSpec 2.6, and sqlite (will move to mysql later on)

Solution

Put the following code in your specs:

Rails 7.0+

ActiveRecord.verbose_query_logs = true

Rails 5.2

ActiveRecord::Base.verbose_query_logs = true

Rails 3.0

ActiveRecord::Base.logger = Logger.new(STDOUT) if defined?(ActiveRecord::Base)

Thanks to everyone who commented for the Rails updates.

Comments

[Phil]

in your test.rb file you may also need to set config.log_level = :debug

[Ed Ruder]

Model.explain doesn't log queries–it executes the DB's EXPLAIN command, which gives you information about how the query will run. Info like: whether it uses an index, how many rows of the DB the query will need to examine, etc.

[Mike Monteiro]

In rails 5.2+, you can also add ActiveRecord::Base.verbose_query_logs = true to see the line of code that is triggering each query

[Dave Powers]

For Rails >= 7.0, the ActiveRecord::Base method has been deprecated. You can instead add ActiveRecord.verbose_query_logs = true to see lines triggering each query.