Eloquent ORM order by deep relation - php

Question

Models:
Category (id, name)
Item (id, name, category_id, ...)
OrderList (id, user_id, ...)
OrderListItem(id, item_id, order_list_id, user_sort_order, ...)
I want OrderListItems of each OrderList to be sorted:
By user_sort_order
Or by Category name
What I do:
$grouped = $request->input('grouped', false) === "true";
$user = User::findOrFail($id);
$order_lists = OrderList::where('kitchen_id', $user->id)
->with(['order_list_items' => function ($q) use ($grouped) {
$q->when($grouped, function ($q) {
return $q->with(['item' => function ($q) {
return $q->with(['category' => function ($q) {
return $q->orderBy('name', 'asc');
}]);
}]);
}, function ($q) {
return $q->orderBy('kitchen_sort_order', 'asc');
})->with('supplier')
->with(['item' => function ($q) {
return $q->with('category');
}]);
}])->get();
Ordering by category name isn't working. I had been searching for hours but found no answer. Is it possible to do something like this in Eloquent ORM? Btw, Django is able to do it in a really nice way.

Answer 1

You can use a HasManyThrough relationship as a BelongsToThrough and combine it with a modified withCount().Not the most elegant solution, but it works:
class OrderListItem extends Model {
public function category() {
return $this->hasManyThrough(Category::class, Item::class,
'id', 'id', 'item_id', 'category_id');
}
}
$order_lists = OrderList::where('kitchen_id', $user->id)
->with(['order_list_items' => function ($q) use ($grouped) {
$q->when($grouped, function ($q) {
return $q->withCount(['category as category_name' => function ($q) {
$q->select('categories.name');
}])->orderBy('category_name');
}, function ($q) {
return $q->orderBy('kitchen_sort_order', 'asc');
})->with('supplier')
->with(['item' => function ($q) {
return $q->with('category');
}]);
}])->get();