实际上 $category->products 是一个对象数组.这就是你不能在对象属性上使用 array_sum 的原因.您可以通过在 类别 型号

Actually the $category->products is an array of objects. Thats why you cant use array_sum on the object attributes. You can get the sum the easy way by adding a STAT relation in the Category Model

'total_inventory'=>array(self::STAT, 'Product', 'cat_id','select'=>'SUM(inventory)')

并且您可以通过调用 $category->total_inventory