How do I describe an enumeration column in a Rails 3 migration?

How do I describe an enumeration column in a Rails 3 migration?

Rails 4.1 contains enum for now!

You can write just

class User < ActiveRecord::Base
  enum status: [ :admin, :user, :banned ]
end

For migration write

t.integer :status

Rails 3 & 4.0

Best solution in my opinion is simple_enum gem.

In a Rails 3 Migration you can do the following:

class CreateFoo < ActiveRecord::Migration
  def change
    create_table :foo do |t|
      t.column :foobar, "ENUM('foo', 'bar')"
    end
  end
end

This will create the table with the single column "foobar" and the values.

You can describe an enumeration column with:

t.column 'role', 'user_role'

I created the enum type with:

execute "CREATE TYPE user_role AS ENUM ('consultant', 'admin');"

Inspecting the database:

    Column     |          Type          | Modifiers | Storage  | Stats target | Description
---------------+------------------------+-----------+----------+--------------+-------------
 role          | user_role              |           | plain    |              |

Something like

class User < ActiveRecord::Base
   validates_inclusion_of :status, :in => [:active, :inactive]

   def status
     read_attribute(:status).to_sym
   end

   def status= (value)
     write_attribute(:status, value.to_s)
   end
 end

I like enumerated_attribute gem: https://github.com/jeffp/enumerated_attribute

Easy enum for your models, objects and views.

Works fine with rails 3.1

This will also work....

add_column :table_name, :column_name, "enum('abc','def','ghi')", :default => 'abc'

I'll use the enum_fu gem: https://github.com/ikspres/enum_fu

What worked for me was mapping it from symbols to integers

TYPE_MAP = { type_one: 1, type_two:2, another_type:3 }

def type
	TYPE_MAP.key(read_attribute(:type))
end

def type=(s)
	write_attribute(:type, TYPE_MAP[s])
end

But for the controller you have to map it again like this:

 def create
  @cupon_type = CuponType.new(params[:cupon_type])
  @cupon_type.type = params[:cupon_type][:type].to_sym

Note the .to_sym that overrides the first creation on the object (in my case it was coupons).

Now you can use it like this:

c.type == :type_one
c.type = :type_two

Have a look at active_enum.

I think it fits your needs.

Use enum_column to add enum support to active record

https://github.com/mdsol/enum_column

t.enum :file_type ,:limit => [:jpg, :png, :gif] ,:default => :gif