Update introspection and migration options for ecto_sql 3.12.0

app/lib/meadow/data/schemas/validations.ex

@@ -10,18 +10,13 @@ defmodule Meadow.Data.Schemas.Validations do
   """
   def prepare_embed(%Ecto.Changeset{data: data, params: params} = change, field)
       when is_atom(field) do
-    empty_struct = fn ->
-      {:parameterized, _type, field_spec} = data.__struct__.__schema__(:type, field)
-      field_spec.related.__struct__ |> Map.from_struct()
-    end
-
     with f <- to_string(field),
          current <- Enum.find([field, f], &Map.get(data, &1)) do
       value =
         cond do
-          Map.has_key?(params, f) and is_nil(Map.get(params, f)) -> empty_struct.()
+          Map.has_key?(params, f) and is_nil(Map.get(params, f)) -> empty_struct(data, field)
           Map.has_key?(params, f) -> Map.get(params, f)
-          is_nil(current) -> empty_struct.()
+          is_nil(current) -> empty_struct(data, field)
           true -> nil
         end
 
@@ -35,4 +30,14 @@ defmodule Meadow.Data.Schemas.Validations do
       end
     end
   end
+
+  defp empty_struct(data, field) do
+    field_spec =
+      case data.__struct__.__schema__(:type, field) do
+        {:parameterized, _type, f} -> f
+        {:parameterized, {_type, f}} -> f
+      end
+
+    field_spec.related.__struct__ |> Map.from_struct()
+  end
 end

app/priv/repo/migrations/20190920155454_create_file_sets.exs

@@ -9,7 +9,7 @@ defmodule Meadow.Repo.Migrations.CreateFileSets do
       add(:extracted_metadata, :map, default: %{})
       add(:structural_metadata, :map, default: %{})
       add(:derivatives, :map, default: %{})
-      add(:work_id, references(:works, null: false, on_delete: :delete_all))
+      add(:work_id, references(:works, on_delete: :delete_all))
       add(:rank, :integer)
       add(:poster_offset, :integer)