Abandoned cart. How to implement correctly?

Question

PHP

Good afternoon!
I'm asking for help in implementing the abandoned cart module in the online store.
You need to send out emails to customers who have not completed the checkout process.
Required for registered users only. Cart made in sessions.
The question is how to save the basket of goods in the database correctly and how to track that the user has left the site and left the basket.
I ask for advice and recommendations!

Answer 1

profseo2012 : so there is no difference in implementation. Now you are writing / reading data to the session, but you need to write to the database.
We also write there the time of the last user activity on the site.
Then we make crons every N minutes, if the last activity of the user was a long time ago, we send letters to him.