Ecto.Adapters.SQL.query/4: When are rows returned as binary rather than [term]?

Questions / Help
,
1

In the @spec of query shows that it can return: %{rows: [binary()]} but I did not found no example returning something similar, in which cases can I receive this kind of return?

2

Where?

source

@spec query(Ecto.Repo.t | Ecto.Adapter.adapter_meta, String.t, [term], Keyword.t) ::
              {:ok, %{:rows => nil | [[term] | binary],
                      :num_rows => non_neg_integer,
                      optional(atom) => any}}
              | {:error, Exception.t}

Example:

$ iex -S mix
Erlang/OTP 21 [erts-10.3.4] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe] [dtrace]

Interactive Elixir (1.8.1) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> {:ok, ecto_result} = Ecto.Adapters.SQL.query(Repo, "select * from artists where id=1")

08:39:49.463 [debug] QUERY OK db=6.3ms decode=0.9ms queue=1.0ms
select * from artists where id=1 []
{:ok, %Postgrex.Result{
   columns: ["id", "name", "birth_date", "death_date", "inserted_at", "updated_at"],
   command: :select,
   connection_id: 3304,
   messages: [],
   num_rows: 1,
   rows: [
     [
       1,
       "Miles Davis",
       nil,
       nil,
       ~N[2019-05-03 00:16:32.000000],
      ~N[2019-05-03 00:16:32.000000]
     ]
   ]
 }}
iex(2)> result = Map.take(ecto_result, [:rows])
%{
  rows: [
    [
      1,
      "Miles Davis",
      nil,
      nil,
      ~N[2019-05-03 00:16:32.000000],
      ~N[2019-05-03 00:16:32.000000]
    ]
  ]
}
iex(3)>
3

@peerreynders in your example you received: rows: [list()], my question is how I can obtain: rows: [binary()]
In @spec %{:rows => nil | [[term] | binary] how that can return rows: [binary]

4

You stated that the spec specified %{rows: [binary()]} - that is incorrect.

My example just extracted the %{:rows => nil | [[term] | binary]} that is part of the spec.

Is your question:

Under what circumstances will %{rows: [binary]} be returned?
(i.e. a binary instead of the typical [term])

Edit: updated topic title

5

I did not say it is incorrect, but I did not find any place returning or explaining how to return rows: [binary]

Under what circumstances will %{rows: [binary]} be returned? Yes, this is my question, Sorry if I was not clear.