Update AuthorRole delete logic to cascade if no Book.

priv/repo/migrations/20250408105711_update_author_role_delete_logic_to_cascade_if_no_book.exs

@@ -0,0 +1,42 @@
+defmodule DecentralisedBookIndex.Repo.Migrations.UpdateAuthorRoleDeleteLogicToCascadeIfNoBook do
+  @moduledoc """
+  Updates resources based on their most recent snapshots.
+
+  This file was autogenerated with `mix ash_postgres.generate_migrations`
+  """
+
+  use Ecto.Migration
+
+  def up do
+    drop constraint(:author_role, "author_role_book_id_fkey")
+
+    alter table(:author_role) do
+      modify :book_id,
+             references(:books,
+               column: :id,
+               name: "author_role_book_id_fkey",
+               type: :uuid,
+               prefix: "public",
+               on_delete: :delete_all
+             )
+    end
+
+    create index(:author_role, [:book_id])
+  end
+
+  def down do
+    drop_if_exists index(:author_role, [:book_id])
+
+    drop constraint(:author_role, "author_role_book_id_fkey")
+
+    alter table(:author_role) do
+      modify :book_id,
+             references(:books,
+               column: :id,
+               name: "author_role_book_id_fkey",
+               type: :uuid,
+               prefix: "public"
+             )
+    end
+  end
+end