change

# File activestorage/db/update_migrate/20191206030411_create_active_storage_variant_records.rb, line 2
  def change
    create_table :active_storage_variant_records do |t|
      t.belongs_to :blob, null: false, index: false
      t.string :variation_digest, null: false

      t.index %[ blob_id variation_digest ], name: "index_active_storage_variant_records_uniqueness", unique: true
      t.foreign_key :active_storage_blobs, column: :blob_id
    end
  end