How to grab children from parent in E-Commerce application - php

Question

I'm actually trying to create an E-Commerce application in Laravel and have the following database layout...
TABLE PRODUCTS:
product_id PK,
material,
description,
brand_id,
category_id,
TABLE PRODUCTS_CHILDREN:
id,
sku,
color,
price,
size,
qty,
product_id (FK to products table)
Now I'm a beginner in Laravel, but I was thinking to build an E-Commerce application and just wanted solve this issue before going to far.
My question is, is there a way, when displaying the products, to also retrieve the products children?
My thought process was:
Products -> get( product_id, $product_id ) -> getChildren ( product_id, product_id );
I know the syntax is not correct, I was just wondering if this was a possible solution in Laravel - by chaining the query ( as I believe is common with the Laravel framework ).
I guess what I'm asking is, what would the blade syntax look when displaying the data?
Judging from what I've seen from tutorials, it seems this would work, but I just wanted to confirm. Thank you for any help!

Answer 1

Yeah it would work once you set up relationships by following the documentation.
For instance, in your example you would have two models, one for the products table and another for the products_children table (I would call them: Product and Variant respectively).
Between them you would have a 1:N relation (one product can have many variants, one variants belongs to one and only one product).
So you could model the relation as following:
Model: Product
class Product
{
// Other methods/properties...
public function variants()
{
return $this->hasMany(Variant::class);
}
}
Model: Variant
class Variant
{
// This is needed, otherwise Laravel would search for a
// table called as the pluralized model name's (eg: variants)
protected $table = 'products_children';
// Other methods/properties...
public function product()
{
return $this->belongsTo(Product::class, 'products_children');
}
}
Once you set up relations like so you can chain methods like your example:
// Assuming $id is the variable holding the product id you want to retrive
$product = Product::find($id);
$variants = $product->variants;
// You can now access the main Product properties, but you can also
// iterate through each Variant entity linked to that product.
Depending on the query use case, the last query might not be the optimal way to do it. You sometimes have to eager-load the relation for all of entities you are querying. If you want to look more in depth about this topic, refer to the official documentation.
Disclaimer: The code I wrote it's just a PoC and hasn't been tested. It was written to give a quick overview about how simple is to setup and use relationships among models.