How to store the quantity of item for different sizes in the database

Question

I am creating an ecommerce app. I cannot find a way to store quantity of different sizes of the same product. Suppose I have at shirt which has 3 sizes available xl,xxl,xxxl with quantity 20 , 25 , 30 . Now how can I store this into the MySQL table ?

One way I was thinking to do this as to create a String like xl+20,xxl+25,xxxl+30 and store it into a column and I can break this String at "," and "+" while retrieving it but I don't think it is a good idea .

Is there any other better way to do this ?

Answer 1

You can break the same product into separate lines for each size, which is scalable in case you want to add or remove things in the future.

id(pk), product_id, size , quantity
1, 100, xl, 20
2, 100, xxl, 25
3, 100, xxxl ,30