Ruby on Rails Add an unique column to a table


Example

To add a new unique column email to users, run the following command:

rails generate migration AddEmailToUsers email:string:uniq

This will create the following migration:

class AddEmailToUsers < ActiveRecord::Migration[5.0]
  def change
    add_column :users, :email, :string
    add_index :users, :email, unique: true
  end
end