class AddPreferencesCountToStudents < ActiveRecord::Migration
  def change
  	add_column :students, :preferences_count, :integer
  end
end

class AddPreferencesCountToStudents < ActiveRecord::Migration
  def change
  	add_column :students, :preferences_count, :integer, default: 0
  end
end

Set preferences_count default to 0
Set preferences_count default to 0
