mobilizon/priv/repo/migrations/20180614094653_make_shared_inbox_url_nullable.exs

defmodule Eventos.Repo.Migrations.MakeSharedInboxUrlNullable do
  use Ecto.Migration

  def up do
    alter table(:actors) do
      modify :shared_inbox_url, :string, null: true, default: nil
    end
  end

  def down do
    alter table(:actors) do
      add :shared_inbox_url, :string, null: false, default: ""
    end
  end
end