Add the Publisher resource.

priv/repo/migrations/20250315185359_add_publisher_and_update_book_relationship.exs

@@ -0,0 +1,44 @@
+defmodule DecentralisedBookIndex.Repo.Migrations.AddPublisherAndUpdateBookRelationship 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
+    create table(:publishers, primary_key: false) do
+      add :id, :uuid, null: false, default: fragment("gen_random_uuid()"), primary_key: true
+      add :name, :text, null: false
+
+      add :inserted_at, :utc_datetime_usec,
+        null: false,
+        default: fragment("(now() AT TIME ZONE 'utc')")
+
+      add :updated_at, :utc_datetime_usec,
+        null: false,
+        default: fragment("(now() AT TIME ZONE 'utc')")
+    end
+
+    alter table(:books) do
+      add :publisher_id,
+          references(:publishers,
+            column: :id,
+            name: "books_publisher_id_fkey",
+            type: :uuid,
+            prefix: "public"
+          )
+    end
+  end
+
+  def down do
+    drop constraint(:books, "books_publisher_id_fkey")
+
+    alter table(:books) do
+      remove :publisher_id
+    end
+
+    drop table(:publishers)
+  end
+end