// dont do a foreing_key, instead use t.references

class CreateDocumentImages < ActiveRecord::Migration[5.1]

  def change

    create_table :document_images do |t|

      t.references :document, foreign_key: { on_delete: :cascade }

      t.references :image, foreign_key: { on_delete: :cascade}

      t.timestamps

    end

  end

end