category id not null but product id can be null same with sku id - product photos

src/Model/Table/ProductPhotosTable.php

@@ -60,6 +60,13 @@ class ProductPhotosTable extends Table
         $this->addBehavior('Timestamp');
 
         $this->addBehavior('Tools.Toggle', [
+            'field' => 'primary_category_photo',
+            'scopeFields' => ['product_category_id'],
+            'scope' => [
+                'deleted IS' => null,
+            ],
+        ]);
+        $this->addBehavior('CakeProducts.SecondToggle', [
             'field' => 'primary_photo',
             'scopeFields' => ['product_id'],
             'scope' => [
@@ -67,14 +74,6 @@ class ProductPhotosTable extends Table
                 'product_id IS NOT' => null,
             ],
         ]);
-        $this->addBehavior('CakeProducts.SecondToggle', [
-            'field' => 'primary_category_photo',
-            'scopeFields' => ['product_category_id'],
-            'scope' => [
-                'deleted IS' => null,
-                'product_category_id IS NOT' => null,
-            ],
-        ]);
         $this->addBehavior('CakeProducts.ThirdToggle', [
             'field' => 'primary_sku_photo',
             'scopeFields' => ['product_sku_id'],
@@ -92,7 +91,7 @@ class ProductPhotosTable extends Table
         $this->belongsTo('ProductCategories', [
             'foreignKey' => 'product_category_id',
             'bindingKey' => 'internal_id',
-            'joinType' => 'LEFT',
+            'joinType' => 'INNER',
             'className' => 'CakeProducts.ProductCategories',
         ]);
 
@@ -121,7 +120,8 @@ class ProductPhotosTable extends Table
 
         $validator
             ->uuid('product_category_id')
-            ->allowEmptyString('product_category_id');
+            ->requirePresence('product_category_id', 'create')
+            ->notEmptyString('product_category_id');
 
         $validator
             ->scalar('photo_dir')