How to compensate for the delay?

Question

MySQL

there is a store on the site, it has goods. Due to the high traffic of the site, goods in the store are bought up very quickly and it happens that 2 people buy one product at the same time. There is a check to see if the product was purchased or not, but due to the micro-delay in updating the database, it turns out that the product is bought from two people. How to be?

Answer 1

Read: transactions and locks

Answer 2

When adding to the cart, it is necessary not only to check for availability, but also to write off (or reserve), then return it if a purchase has not been made

Answer 3

At the time of purchase of the goods, use a transaction and a request of the form select for update
Detailed in the documentation

Answer 4

It can be configured so that the product with less than N pieces left is not available for purchase or is marked something like "remains in stock - unknown". In this case, when approaching the minimum, the user simply will not be able to add the product to the cart instead of a bummer when placing an order, or at least be ready for this bummer, realizing that the product may no longer be available.