Update

lib/nulla_web/controllers/api/relation_controller.ex

@@ -0,0 +1,43 @@
+defmodule NullaWeb.Api.RelationController do
+  use NullaWeb, :controller
+
+  alias Nulla.Relations
+  alias Nulla.Relations.Relation
+
+  action_fallback NullaWeb.FallbackController
+
+  def index(conn, _params) do
+    relations = Relations.list_relations()
+    render(conn, :index, relations: relations)
+  end
+
+  def create(conn, %{"relation" => relation_params}) do
+    with {:ok, %Relation{} = relation} <- Relations.create_relation(relation_params) do
+      conn
+      |> put_status(:created)
+      |> put_resp_header("location", ~p"/api/relations/#{relation}")
+      |> render(:show, relation: relation)
+    end
+  end
+
+  def show(conn, %{"id" => id}) do
+    relation = Relations.get_relation!(id)
+    render(conn, :show, relation: relation)
+  end
+
+  def update(conn, %{"id" => id, "relation" => relation_params}) do
+    relation = Relations.get_relation!(id)
+
+    with {:ok, %Relation{} = relation} <- Relations.update_relation(relation, relation_params) do
+      render(conn, :show, relation: relation)
+    end
+  end
+
+  def delete(conn, %{"id" => id}) do
+    relation = Relations.get_relation!(id)
+
+    with {:ok, %Relation{}} <- Relations.delete_relation(relation) do
+      send_resp(conn, :no_content, "")
+    end
+  end
+end