Let Elixir do its magic

lib/cadet/assessments/submission.ex

@@ -43,9 +43,9 @@ defmodule Cadet.Assessments.Submission do
     |> validate_xor_relationship
     |> validate_required(@required_fields)
     |> foreign_key_constraint(:student_id)
+    |> foreign_key_constraint(:team_id)
     |> foreign_key_constraint(:assessment_id)
     |> foreign_key_constraint(:unsubmitted_by_id)
-    |> unique_constraint(:unique_team_id, name: :submissions_team_id_assessment_id_unique_index)
   end
 
   defp validate_xor_relationship(changeset) do

priv/repo/migrations/20241014200600_create_teams_submission_constraint.exs

@@ -1,17 +1,8 @@
 defmodule Cadet.Repo.Migrations.CreateTeamsSubmissionConstraint do
   use Ecto.Migration
 
-  def up do
-    create(
-      unique_index(
-        :submissions,
-        [:team_id, :assessment_id],
-        name: :submissions_team_id_assessment_id_unique_index
-      )
-    )
-  end
-
-  def down do
-    drop(constraint(:submissions, :submissions_team_id_assessment_id_unique_index))
+  def change do
+    create(index(:submissions, :team_id))
+    create(unique_index(:submissions, [:assessment_id, :team_id]))
   end
 end