diff --git a/config/Migrations/20251101150009_AllowProductIdToBeNullInProductPhotos.php b/config/Migrations/20251101150009_AllowProductIdToBeNullInProductPhotos.php
new file mode 100644
index 0000000..a18fb7c
--- /dev/null
+++ b/config/Migrations/20251101150009_AllowProductIdToBeNullInProductPhotos.php
@@ -0,0 +1,25 @@
+<?php
+declare(strict_types=1);
+
+use Migrations\BaseMigration;
+
+class AllowProductIdToBeNullInProductPhotos extends BaseMigration
+{
+    /**
+     * Change Method.
+     *
+     * More information on this method is available here:
+     * https://book.cakephp.org/migrations/4/en/migrations.html#the-change-method
+     * @return void
+     */
+    public function change(): void
+    {
+        $table = $this->table('product_photos');
+        $table->changeColumn('product_id', 'uuid', [
+            'default' => null,
+            'limit' => 11,
+            'null' => true,
+        ]);
+        $table->update();
+    }
+}
diff --git a/src/Model/Entity/ProductPhoto.php b/src/Model/Entity/ProductPhoto.php
index a925d3a..4a3056e 100644
--- a/src/Model/Entity/ProductPhoto.php
+++ b/src/Model/Entity/ProductPhoto.php
@@ -10,7 +10,7 @@ use Cake\ORM\Entity;
  * ProductPhoto Entity
  *
  * @property string $id
- * @property string $product_id
+ * @property string|null $product_id
  * @property string|null $product_category_id
  * @property string|null $product_sku_id
  * @property string $photo_dir
@@ -55,6 +55,8 @@ class ProductPhoto extends Entity
         'deleted' => true,
 
         // entities
-        'product' => true,
+        'product' => false,
+        'product_sku' => false,
+        'product_category' => false,
     ];
 }
diff --git a/src/Model/Table/ProductCategoryAttributeOptionsTable.php b/src/Model/Table/ProductCategoryAttributeOptionsTable.php
index e224c6a..54e1e57 100644
--- a/src/Model/Table/ProductCategoryAttributeOptionsTable.php
+++ b/src/Model/Table/ProductCategoryAttributeOptionsTable.php
@@ -108,6 +108,7 @@ class ProductCategoryAttributeOptionsTable extends Table
     public function buildRules(RulesChecker $rules): RulesChecker
     {
         $rules->add($rules->existsIn(['product_category_attribute_id'], 'ProductCategoryAttributes'), ['errorField' => 'product_category_attribute_id']);
+        $rules->add($rules->isUnique(['attribute_value', 'product_category_attribute_id']));
 
         return $rules;
     }
diff --git a/src/Model/Table/ProductCategoryVariantOptionsTable.php b/src/Model/Table/ProductCategoryVariantOptionsTable.php
index 954ec11..f564fa4 100644
--- a/src/Model/Table/ProductCategoryVariantOptionsTable.php
+++ b/src/Model/Table/ProductCategoryVariantOptionsTable.php
@@ -105,6 +105,7 @@ class ProductCategoryVariantOptionsTable extends Table
     public function buildRules(RulesChecker $rules): RulesChecker
     {
         $rules->add($rules->existsIn(['product_category_variant_id'], 'ProductCategoryVariants'), ['errorField' => 'product_category_variant_id']);
+        $rules->add($rules->isUnique(['variant_value', 'product_category_variant_id']));
 
         return $rules;
     }