Claper/lib/claper/stats.ex

defmodule Claper.Stats do
  @moduledoc """
  The Stats context.
  """

  import Ecto.Query, warn: false
  alias Claper.Repo

  def distinct_poster_count(event_id) do
    from(posts in Claper.Posts.Post,
      where: posts.event_id == ^event_id,
      select: count(posts.user_id, :distinct) + count(posts.attendee_identifier, :distinct)
    )
    |> Repo.one()
  end

  def total_vote_count(presentation_file_id) do
    from(p in Claper.Polls.Poll,
      join: pv in Claper.Polls.PollVote,
      on: pv.poll_id == p.id,
      where: p.presentation_file_id == ^presentation_file_id,
      group_by: p.presentation_file_id,
      select:
        count(
          fragment("DISTINCT COALESCE(?, CAST(? AS varchar))", pv.attendee_identifier, pv.user_id)
        )
    )
    |> Repo.all()
  end
end