phoenix: find or create model

find_or_create_model.ex

def find_or_create_upload(find_fields, create_attrs \\ %{}) do
  filters = Map.take(create_attrs, find_fields) |> Map.to_list()
  query = from(u in Upload, where: ^filters)
  upload = Repo.one(query)

  if upload == nil do
    create_upload(create_attrs)
  else
    upload
  end
end