change

# File activestorage/db/update_migrate/20191206030411_create_active_storage_variant_records.rb, line 2
  def change
    return unless table_exists?(:active_storage_blobs)

    # Use Active Record's configured type for primary key
    create_table :active_storage_variant_records, id: primary_key_type, if_not_exists: true do |t|
      t.belongs_to :blob, null: false, index: false, type: blobs_primary_key_type
      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