Eloquent ORM | Trying to understand relations in Laravel 5.6 - php

Question

Stackoverflow.
I'm newbie to PHP and Laravel. I'm learning it by creating ecommerce shop system.
So the question is about Eloquent ORM and Relations in system.
I have Brands Catalog with Products that belongs to Brand. Than I want to create Catalog with Products, Types, Variants and Photos.
Project Scheme
On scheme below you can see the relations and DB migrations done now.
The Problem
What I have done:
Models relations;
Brand controller (simple CRUD with slug);
What I need to do:
Create adding Product logic (Only 1 ProductVariant).
When adding new Product, by default, it should create 1 ProductVariant with
datas (e.g. ASUS (Brand), ROG (Product), Notebook (Type), Zephyrus (Variant)).
Create adding Product logic (More than 1 ProductVariant).
When adding new Product, but Product has >1 ProductVariant(e.g. Intel (Brand), Core i7 (Product), CPU (Type) and Variants 7700, 7700K, 7600).
So, when I'm creating product (e.g. product/add.blade.php view).
With example form:
<form action="{{ route('name of add route) }} method="post">
here goes brand select with options (foreach brands as brand)
than goes type select with options (foreach types as type)
than goes inputs for Product (name, country, etc.)
than goes inputs for ProductVariant (name, description, price, etc.)
than goes inputs for another ProductVariant.
</form>
The Question
Am I done all relations correctly?
How should I store this data in DB in Controller?
Also, I have Controllers for Product, ProductVariant, ProductType.
I will be very grateful if someone can help me

Answer 1

It's too long to write whole code here or describe how to save relational data in laravel.
Please have a look official documentation and this small tutorial
Connected with correct relationships
Depending on your example I think that you need to have additional description fields for tables Product and ProductVariant, to store short info about product or concrete variant of product.
Also I think that will be a lot of product photos, which will be independent of product variant (will be the same for all variants of that product). To do not have duplicates of photos for each variant you can change ProductPhotos table structure:
id
product_id - belongs to Product
product_variant_id - belongs to ProductVariant (NULL if its for all variants of that product)
photo_url
So to get all photos for concrete variant of product you can get
all photos for that product which are not connected with variant
(product_variant_id IS NULL)
plus all photos for that variant