Hello.

I am fairly new to Phoenix/elixir, but I read the doc and couldn’t find what I was looking for.
I am currently working on a basic Phoenix API. After studying a bit the Ecto documentation, I found the lines about Ecto.get and get_by, which helped me adding new endpoints to request the database with another argument than the id.

Now, I am stuck, because when I request some id which isn’t on the API, it raise a error " Ecto.NoResultsError". What I want is a empty data, or nil, so my other program can check if there is content matching the request.

I undestand the Exception came from the Repo.get, so I tried to rewrite my show function in the controller like that :

def show(conn, %{"accession_number" => accession_number}) do
    try do
      dicom = DICOM.get_dicom_an!(accession_number)
      render(conn, "show.json", dicom: dicom)
    rescue
      e in RuntimeError -> IO.puts(e.message)
      render(conn, "show.json", "")
    end
  end

However, I couldn’t get it to work. I also tried to pattern match
with error in the delete function, but I couldn’t make it work.

What is the way to achieve what I want ?