CODE EXAMPLE FOR ELIXIR

elixir ecto pluck ids

ids = [123, 4, 1, 3, 2, 456]
posts = from(p in Post, where: p.id in ^ids, select: {p.id, p}) 
  		|> Repo.all 
		|> Map.new
posts = for id <- ids, posts[id], do: posts[id]
posts |> Enum.map(&(&1.id)) |> IO.inspect