write-in-both-columns.ex

defmodule WttjApi.Accounts.User do
  use Ecto.Schema
  import Ecto.Changeset

  def create_changeset(user, attrs \\ %{}) do
    user
    |> cast(attrs, [:title, :gender])
    |> migrate_title_to_gender()
  end

  defp migrate_title_to_gender(changeset) do
    case get_change(changeset, :title) do
      nil ->
        changeset

      title ->
        gender =
          case title do
            "Mr" -> "man"
            "Ms" -> "woman"
          end

        changeset
        |> put_change(:gender, gender)
    end
  end
end