Programming Ecto

Saving the Table-less Structs

To save the data from these schemas into the artists table, we have a couple of options. One way would be to add extra changeset functions to our Artist schema that take a Band or SoloArtist struct as input:

lib/music_db/artist.ex

def changeset(%MusicDB.Band{} = band) do
  {:ok, birth_date} = Date.new(band.year_started, 1, 1)
  {:ok, death_date} = Date.new(band.year_ended, 12, 31)

  changeset(%Artist{
    name: band.name,
    birth_date: birth_date,
    death_date: death_date
  }, %{})
end

def changeset(%MusicDB.SoloArtist{} = solo_artist) do
  name =
    "#{solo_artist.name1} #{solo_artist.name2} #{solo_artist.name3}