Schema design for products with multiple variants/attributes?

I'm using MySQL. The idea is similar to shopify with a different concept, so users are going to add their own products with multiple types of variants and attributes.

From all the research I've done this seems the most likely solution for me and I'm just wondering if there's anything wrong with the following schema and what are the upsides/downsides?

Thank you

```
Table: products
------------------------------
| ID | ProductName |
|----------------------------|
| 1 | Leather Wallet Case |
| 2 | Jeans |
| 3 | Power Bank |

Table: products_variants
-------------------------------
| ID | ProductId | ParentId | Variant | VariantName | SKU | StockTotal | WholeSalePrice | BuyPrice | OnSale | OnSalePrice |
|---------------------------------------------------------------------------------------------------------------------------|
| 1 | 1 | null | model | iPhone5 | SKU | 10 | 3 | 10 | null | null |
|---------------------------------------------------------------------------------------------------------------------------|
| 2 | 1 | null | model | iPhone4 | null | null | null | null | null | null |
| 3 | 1 | 2 | color | Red | SKU | 10 | 3 | 10 | null | null |
| 4 | 1 | 2 | color | Blue | SKU | 10 | 3 | 10 | null | null |
|---------------------------------------------------------------------------------------------------------------------------|
| 5 | 2 | null | size | M | null | null | null | null | null | null |
| 8 | 2 | 5 | color | Black | SKU | 10 | 3 | 10 | null | null |
| 9 | 2 | null | size | XXL | SKU | 10 | 3 | 10

This is just the info from @lesandru reply, I really find it very useful, so credits to him and @sahalMoidu

Applying normalization to your problem the solution is as given. Run and see it on Fiddle

Fiddle

CREATE TABLE products 
    (
     product_id int auto_increment primary key, 
     name varchar(20), 
     description varchar(30)

    );

INSERT INTO products
(name, description)
VALUES
('Rug', 'A cool rug'  ),
('Cup', 'A coffee cup');

create table variants (variant_id int auto_increment primary key,
                       variant varchar(50)
                       );
insert into variants (variant)
values ('color'),('material'),('size') ;   
create table variant_value(value_id int auto_increment primary key, 
                           variant_id int ,
                           value varchar(50)
                           );

insert into variant_value (variant_id,value)
values (1 ,'red'),(1 ,'blue'),(1 ,'green'),
        (2 ,'wool'),(2 ,'polyester'),
        (3 ,'small'),(3 ,'medium'),(3 ,'large');

create table product_Variants( product_Variants_id int  auto_increment primary key,
                            product_id int,
                            productVariantName varchar(50),
                            sku varchar(50),
                            price float
                            );

create table product_details(product_detail_id int auto_increment primary key,
                             product_Variants_id int,

                             value_id int
                             );

insert into product_Variants(product_id,productVariantName,sku,price)
values (1,'red-wool' ,'a121',50);

insert into product_details(product_Variants_id , value_id)
values( 1,1),(1,4);

insert into product_Variants(product_id,productVariantName,sku,price)
values (1,'red-polyester' ,'a122',50);

insert into product_details(product_Variants_id , value_id)
values( 2,1),(2,5);

StackExchange Database Administrators Q#123467, answer score: 7