ActiveRecordUUIDAsPK

activerecord_uuid_as_pk is a extension for ActiveRecord to enable to use uuid for id attribute (v1.0.0 tested only MySQL).

Installation

Add this line to your application's Gemfile:

gem 'activerecord_uuid_as_pk'

And then execute:

$ bundle

Or install it yourself as:

$ gem install activerecord_uuid_as_pk

Usage

In a migration file, prevent generate id column and add uuid column (tinyblob).

class CreateUsers < ActiveRecord::Migration
    def up
        create_table :users, :id => false do |t|
            t.column :uuid, :tinyblob
            t.string :user_name
        end
        execute "ALTER TABLE users ADD PRIMARY KEY (`uuid`(16))"
    end
    def down
        drop_table :users
    end
end

Call uuid_as_primary_key method in a model class.

class User < ActiveRecord::Base
    uuid_as_primary_key
end

The uuid_as_primary_key method hooks before_create callback to set automatically generated uuid as 16 byte binary data to id attirbute. And this method adds #formatted_id to the model to refer formatted uuid.
```
user = User.create(:user_name => "foo")
user.id  #=> "3~\x05v\xCBfAQ\xA2\xE1\xE0\xFC\x04\xFB3\xD1"
user.formatted_id  #=> "337e0576-cb66-4151-a2e1-e0fc04fb33d1"
```

Of course you can set arbitrary uuid if you set 16 byte binary, a formatted uuid string or UUIDTools::UUID object to id attribute. A formatted uuid string and UUIDTools::UUID object will be converted 16 byte binary data when you save a model.

user1 = User.create(:id => UUIDTools::UUID.parse("f311427a-954c-46f5-92df-3d37f56b5b41").raw, :user_name => "user1")
user1.formatted_id
    #=> "f311427a-954c-46f5-92df-3d37f56b5b41"
user2 = User.create(:id => "206b38d7-3b5f-4645-b5b2-5e7efea1d3ca", :user_name => "user2")
user2.formatted_id
    #=> "206b38d7-3b5f-4645-b5b2-5e7efea1d3ca"
user3 = User.create(:id => UUIDTools::UUID.parse("c81836c5-309a-4608-bf1a-5fe343081a92"), :user_name => "user3")
user3.formatted_id
    #=> "c81836c5-309a-4608-bf1a-5fe343081a92"

The uuid_as_primary_key method also adds find_by_formatted_id class method to retrive model from data store with a formatted uuid string.
```
User.find_by_formatted_id("337e0576-cb66-4151-a2e1-e0fc04fb33d1")
```

Contributing

Fork it
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request