class CreateVirologyVersions < ActiveRecord::Migration[5.1]
  def change
    create_table :virology_versions do |t|
      t.string   :item_type, null: false
      t.integer  :item_id,   null: false
      t.datetime :created_at
    end
    add_index :virology_versions, [:item_type, :item_id]
  end
end