Question to get my head around setting up a database for a one to one and one to many service.
I am thinking about how to design certain tables in a multi vendor, multi services database.
One provider can sell a cooking class for a certain time to many people and another may sell a chocolate making consultancy to just one person.

There is a transaction table,
transaction line items table,
listings table,
availability table,
booking table,
user table etc.
The transaction table contains a seller ID, buyer ID, listing ID, price etc.
The ‘transaction lines item table’ contains the fields quantity, product ID, transaction ID etc.
Should I add a separate quantity table to not confuse payment providers such as Stripe or PayPal or does the quantity option in the ‘transaction times table’ deal with the issue?

Thanks in advance.