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.