ecto get parents/children

gistfile1.ex

defmodule Node do
  import Ecto.Query, only: [from: 2]

  def get_children(node) do
    from(n in Node,
         join: n2n in NodeToNode, on: n.id == n2n.parent_id,
         inner_join: n1 in Node, on: n1.id == n2n.child_id,
         select: n1,
         where: n.id == ^node.id)
    |> Repo.all
  end

  def get_parents(node) do
    from(n in Node,
         join: n2n in NodeToNode, on: n.id == n2n.child_id,
         inner_join: n1 in Node, on: n1.id == n2n.parent_id,
         select: n1,
         where: n.id == ^node.id)
    |> Repo.all
  end
end