README.md
# Rails SQL Query Tracker
[](https://codeclimate.com/github/steventen/sql_tracker)
[](https://travis-ci.org/steventen/sql_tracker)
`sql_tracker` tracks SQL queries by subscribing to Rails' `sql.active_record` event notifications.
It then aggregates and generates report to give you insights about all the sql queries happened in your Rails application.
## Installation
Add this line to your application's Gemfile:
```ruby
group :development, :test do
... ...
gem 'sql_tracker'
end
```
And then execute:
$ bundle
## Tracking
To start tracking, simply start your rails application server. When your server is shutting down, `sql_tracker` will dump all the tracking data into one or more json file(s) under the `tmp` folder of your application.
`sql_tracker` can also track sql queries when running rails tests (e.g. your controller or integration tests), it will dump the data after all the tests are finished.
### Tracking Using a Block
It is also possible to track queries executed within a block. This method uses a new subscriber to `sql.active_record` event notifications for each invocation. Results using this method are not saved to a file.
```ruby
query_data = SqlTracker.track do
# Run some active record queries
end
query_data.values
# =>
# [{
# :sql=>"SELECT * FROM users",
# :count=>1,
# :duration=>1.0,
# :source=>["app/models/user.rb:12"]
# }]
```
## Reporting
To generate report, run
```bash
sql_tracker tmp/sql_tracker-*.json
```
The output report looks like this:
```
==================================
Total Unique SQL Queries: 24
==================================
Count | Avg Time (ms) | SQL Query | Source
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
8 | 0.33 | SELECT `users`.* FROM `users` WHERE `users`.`id` = xxx LIMIT 1 | app/controllers/users_controller.rb:125:in `create'
| | | app/controllers/projects_controller.rb:9:in `block in update'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
4 | 0.27 | SELECT `projects`.* FROM `projects` WHERE `projects`.`user_id` = xxx AND `projects`.`id` = xxx LIMIT 1 | app/controllers/projects_controller.rb:4:in `update'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2 | 0.27 | UPDATE `projects` SET `updated_at` = xxx WHERE `projects`.`id` = xxx | app/controllers/projects_controller.rb:9:in `block in update'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2 | 1.76 | SELECT projects.* FROM projects WHERE projects.priority BETWEEN xxx AND xxx ORDER BY created_at DESC | app/controllers/projects_controller.rb:35:in `index'
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
... ...
```
By default, the report will be sorted by the total count of each query, you can also choose to sort it by average duration:
```bash
sql_tracker tmp/sql_tracker-*.json --sort-by=duration
```
## Configurations
All the configurable variables and their defaults are list below:
```ruby
SqlTracker::Config.enabled = true
SqlTracker::Config.tracked_paths = %w(app lib)
SqlTracker::Config.tracked_sql_command = %w(SELECT INSERT UPDATE DELETE)
SqlTracker::Config.output_path = File.join(Rails.root.to_s, 'tmp')
```
## License
The gem is available as open source under the terms of the [MIT License](http://opensource.org/licenses/MIT).