Hi,

Repo.insert, Repo.update and Repo.delete all return {:ok, resource} or {:error, changeset}.

But Repo.get and Repo.get_by return resource or nil.

I also noticed a decent amount of custom code (such as the Programming Phoenix Rumbl example app) prefers to use the tuple style, such as the RumblWeb.Auth.login_by_email_and_pass function returning {:ok, conn} or {:error, _reason, conn}.

That made me very curious. Why doesn’t Repo.get return {:ok, resource} or {:error, :resource_not_found}?

If it’s an API oversight and too late to change, what do you think about adding this custom function to your lib/myapp/repo.ex and always using this instead of get_by?

  def fetch_by(queryable, clauses, opts \\ []) do
    case get_by(queryable, clauses, opts) do
      nil ->
        {:error, :resource_not_found}

      resource ->
        {:ok, resource}
    end
  end

The fetch function (not included here) would do the same thing, except wrap get.

Edit: For clarity, it would be useful to have this because when pattern matching on else when using with it’s a lot more obvious to see what went wrong when you match on something like {:error, :resource_not_found} vs matching on nil.