How to solve the database operation with react as the back end of UIkit express?

  node.js, question

For example, a Landing Page must have a database operation, a post request, how to query the database?
Or what if you want to transfer data to the page?
Then you want to keep persistent data?

PS: What is the database operation in Flux?

I haven’t used recat, but generally the front-end and back-end interaction is AJAX. The back-end uses PHP or other server languages to receive data and write it into the database.
Or is there a new method now?