Laravel call relation from model in when() conditional clauses - laravel

Question

I am creating product filtering and now I have problem when I want to filter product category by name.
I am not sure if is possible to call relation inside when() conditional clauses.
In the product controller, I create:
$results = Product::query();
// Conditional filter
$results->when($request->has('product_code'), function ($q) use ($request) {
return $q->where('product_code', 'like', '%'.$request->query('product_code').'%');
});
$results->when($request->has('status'), function ($q) use ($request) {
return $q->where('status', $request->query('status'));
});
$results->when($request->has('price'), function ($q) use ($request) {
return $q->where('price', $request->query('price'));
});
// Filter by category NAME
// HERE IS PROBLEM
$results->when($request->has('category_name'), function ($q) use ($request) {
return $q->category->where('name', $request->query('cat_name'));
});
// I also try
// This return SQLSTATE[42S22]: Column not found: 1054 Unknown column 'category.name' in 'where clause' (SQL: select count(*) as aggregate from `products` where `category`.`name` = Apple)
$results->when($request->has('category_name'), function ($q) use ($request) {
return $q->where('category.name', $request->query('cat_name'));
});
$results = $results->paginate(20);
Model:
class Product
{
public function category()
{
return $this->hasOne('App\Models\Category', 'id', 'category_id');
}
}

Answer 1

for this filtering do this:
$filter = [];
if($request->product_code!= null)
array_push($filter, ['product_code', 'like', "%$request->product_code%"]);
if($request->price)
array_push($filter, ['price', $request->price]);
// and so on ...
then you have array of conditions, just call where and pass the array:
$results = Product::where($filter);

Answer 2

How about that?
$category_ids = Category::where('category_name', $request->query('category_name'))->pluck('id');
$results = Product::select("*")->when($request->has('category_name'), function ($query) use ($request, $category_ids) {
return $query->whereIntegerInRaw('category_id', $category_ids);
})->get();