PgTypes

PgTypes provides Rails integration for managing PostgreSQL custom types (composite types, enums, domains). It allows you to version your custom types and handle them through migrations, similar to how you manage database schema changes, while maintaining a clean schema.rb file.

• Versioned PostgreSQL types
• Rails generator for creating new types
• Migration support for adding/removing types
• Proper schema.rb dumping (no need for structure.sql)
• Support for multiple PostgreSQL versions
• Support for composite types, enums, and domains
• Dependencies tracking and proper ordering

Add this line to your application's Gemfile:

gem 'pg_types'

And then execute:

$ bundle install

Generate a new type:

# Create a simple type
$ rails generate pg:type contact_info

# Create a type with fields
$ rails generate pg:type contact_info --fields email:text phone:varchar active:boolean

# Create a specific version
$ rails generate pg:type contact_info --version 2

This will create:

• A SQL file in db/types/contact_info_v1.sql
• A migration file to create the type

Edit the generated SQL file (db/types/contact_info_v1.sql):

CREATE TYPE contact_info AS (
  email text,
  phone varchar,
  active boolean
);

For an enum type:

CREATE TYPE status AS ENUM (
  'active',
  'pending',
  'inactive'
);

For a domain type:

CREATE DOMAIN positive_integer AS integer
  CHECK (VALUE > 0);

The generated migration will look like:

class CreateTypeContactInfo < ActiveRecord::Migration[7.0]
  def change
    create_type "contact_info", version: 1
  end
end

You can also create types inline:

class CreateTypeUserStatus < ActiveRecord::Migration[7.0]
  def change
    create_type "user_status", sql_definition: <<-SQL
      CREATE TYPE user_status AS ENUM (
        'active',
        'pending',
        'inactive'
      );
    SQL
  end
end

When you need to update a type, create a new version:

1. Generate a new version:

$ rails generate pg:type contact_info --version 2 --fields email:text phone:varchar active:boolean preferences:jsonb

2. Update the SQL in db/types/contact_info_v2.sql

3. Create a migration to update to the new version:

class UpdateTypeContactInfo < ActiveRecord::Migration[7.0]
  def change
    drop_type "contact_info", force: true  # Use force: true if the type is used in tables
    create_type "contact_info", version: 2
  end
end

After creating your types, you can use them in your models:

# For composite types
class User < ApplicationRecord
  attribute :contact_info, :contact_info  # Requires additional setup with ActiveRecord
end

# For enum types
class User < ApplicationRecord
  enum status: {
    active: 'active',
    pending: 'pending',
    inactive: 'inactive'
  }, _prefix: true
end

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 run tests against multiple Rails versions:

bundle exec appraisal install
bundle exec appraisal rake spec

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

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

Everyone interacting in the PgTypes project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.