How to build a query on laravel correctly?

Question

I am grateful in advance for any answer!

there are CATEGORIES

• CATEGORIES (one) 1⟶n PRODUCTS (many)
• PRODUCTS (many) m⟶n STORE (one)
• STORES (one) 1⟶n ADDRESS_CITY (many)

CATEGORIES → PRODUCTS → STORES → ADDRESS_CITY

you must select all the CATEGORIES that have:

• there is at least 1 PRODUCT / / has
• this PRODUCT must have a STORE in which the ADDRESS exists in California

I tried to build a query, it does not work, there is only the hasManyThrough method in the documentation
that jumps through 1 table, and there are more of them here. Or I'm even being stupid)
Help to build a query!

Another question: if I have 1 million products and 1000 stores, will the request be processed normally or do I need to look for other FEATURES:

• save the id_city in JSON in the PRODUCTS
• save the id_city in JSON in the STORE

Answer 1

$result = Category::where('on_off', 1)
    ->whereHas('product', function ($query) use ($city_one) {
        $query->where('on_off', 1)

            ->whereHas('shop', function ($query) use ($city_one) {
                $query->where('on_off', 1)

                    ->whereHas('shop_map_point', function ($query) use ($city_one) {
                        $query->where('city_id', $city_one->id);
                    });
            });
    })
    ->get();