ar-enum

Add support for creating ENUM types in PostgreSQL with ActiveRecord. This gem is no longer required for Rails 7.0+.

Installation

Add this line to your application's Gemfile:

gem "ar-enum"

And then execute:

$ bundle

Or install it yourself as:

$ gem install ar-enum

Usage

Creating enums

To create a enum type, use the method create_enum.

# The type is created independently from the table.
create_enum :article_status, %w[draft published]

create_table :articles do |t|
  # Use the type `article_status` when defining your column.
  t.column :status, :article_status, null: false, default: "draft"
end

You can even use the type shortcut if you want; i.e. you can use t.article_status instead of t.column.

# The type is created independently from the table.
create_enum :article_status, %w[draft published]

create_table :articles do |t|
  # Use the type `article_status` when defining your column.
  t.article_status :status, null: false, default: "draft"
end

Dropping enums

To remove the enum, use drop_enum.

drop_enum :article_status

You'll receive a ActiveRecord::StatementInvalid if any of your tables have a dependency on the type; i.e. you're have a column using that enum. You can drop these columns by specifying cascade: true.

drop_enum :article_status, cascade: true

If you don't want to remove the column, change the column type before dropping the enum.

change_column :articles, :status, :text
drop_enum :article_status

Adding new labels

Use add_enum_label to add new values to the enum type. You can control where the value will be inserted by using before: label and after: label.

create_enum :article_status, %w[draft published]

# labels will be sorted as [draft, published, unlisted]
add_enum_label :article_status, "unlisted"

# labels will be sorted as [draft, unlisted, published]
add_enum_value :article_status, "unlisted", after: "draft"

# labels will be sorted as [draft, unlisted, published]
add_enum_value :article_status, "unlisted", before: "published"

WARNING: PostgreSQL does not have a way of removing values from enum types.

Renaming existing labels

Use rename_enum_label to rename a value.

create_enum :article_status, %w[draft unlisted published]

# labels will be [draft, unlisted, live]
rename_enum_label :article_status, "published", "live"

Reversing changes

The following commands can be reversed:

• create_enum
• rename_enum_label

class CreateColorEnumClass < ActiveRecord::Migration
  def change
    create_enum :color, %w[red blue black]
  end
end

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/fnando/ar-enum. 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.