keep inserted_at value to the original value, #30

lib/alog.ex

@@ -248,6 +248,19 @@ defmodule Alog do
           User.all()
       """
       def all do
+        # get the oldest items
+        sub =
+          from(m in __MODULE__,
+            distinct: m.entry_id,
+            order_by: [asc: :inserted_at],
+            select: m
+          )
+
+        query = from(m in subquery(sub), where: not m.deleted, select: m)
+
+        oldest_items = @repo.all(query)
+
+        # get the most recent inserted items, ie desc: :inserted_at
         sub =
           from(m in __MODULE__,
             distinct: m.entry_id,
@@ -258,6 +271,14 @@ defmodule Alog do
         query = from(m in subquery(sub), where: not m.deleted, select: m)
 
         @repo.all(query)
+        |> Enum.map(fn(newest_item) ->
+          oldest_item = Enum.find(oldest_items, &(&1.entry_id == newest_item.entry_id))
+          if oldest_item do
+            %{newest_item | inserted_at: oldest_item.inserted_at}
+          else
+            newest_item
+          end
+        end)
       end
 
       @doc """

test/all_test.exs

@@ -14,9 +14,10 @@ defmodule AlogTest.AllTest do
     test "does not include old items" do
       {:ok, user} = %User{} |> User.changeset(Helpers.user_1_params()) |> User.insert()
       {:ok, _} = %User{} |> User.changeset(Helpers.user_2_params()) |> User.insert()
-      {:ok, _} = user |> User.changeset(%{postcode: "W2 3EC"}) |> User.update()
+      {:ok, user_updated} = user |> User.changeset(%{postcode: "W2 3EC"}) |> User.update()
 
       assert length(User.all()) == 2
+      assert user.inserted_at == user_updated.inserted_at
     end
   end
 end