Ruby [Migration]: Change Field/Column Data Type

change_column_data_type.rb

class ChangeDataTypeForWidgetCount < ActiveRecord::Migration
  def self.up
    change_table :widgets do |t|
      t.change :count, :float
    end
  end

  def self.down
    change_table :widgets do |t|
      t.change :count, :integer
    end
  end
end