如何在Laravel中使用whereHas多层次关系

Question

How to use whereHas on multilevel relationship like:

$parentCats = Category::with(
    'children',
    'children.products',
    'children.products.productDetails'
);

Now I want to do query like:

$parentCats = $parentCats->whereHas(
    'children.products.productDetails',
    function ($q2) use ($size) {
        $q2->where('size', '=', $size);
    }
)->find($id);

this query is giving all data. But I want data only where productDetails have given size.