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

Question

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

Answer 1

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.

Answer 2

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    |              |

Answer 3

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

Answer 4

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

Answer 5

This will also work....

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