ActiveRecordUniquenessViaDb

This simplifies validations by uniqueness using db constraints. Rails uniqueness validations are not safe for concurrent processes, so we need to add a db constraint anyway to ensure values are unique in the database. This allows us to just rely on the error that constraint raises rather than perform an extra select statement prior to insert/updates

validate :some_key, uniqueness: { via: :db }

the rails uniqueness validation already accepts options rather than a simple truthy value, this gem adds the :via key to those options

-supported adapters: mysql2, postgresql

Installation

Add this line to your application's Gemfile:

gem 'active_record_uniqueness_via_db'

And then execute:

$ bundle

Or install it yourself as:

$ gem install active_record_uniqueness_via_db

Notes:

• if you are upgrading from VERSION <= v0.1.1, remove the initializers
• if you use the composite_primary_keys gem, ensure that gem 'active_record_uniqueness_via_db' is included after the reference for composite_primary_keys. (This is necessary because composite_primary_keys rather than extending the uniqueness validation overwrites it, in contrast, this gem just extends the functionality so they play nice together as long as this gem comes after that one).

Usage

validate :some_key, uniqueness: { via: :db }

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Note: to add databases, add a file under lib/adapters/db_adapter_name.rb that implements the error_matches_att method

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/jamesmacwilliam/active_record_uniqueness_via_db. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.