You will find limited support to write a full thing for you... we all have our projects and can help sharing ideas when someone is stuck, but if you want someone to write code for you, then it's more for the Gigs and Collaboration forum (and expect to pay for this).
On your needs:
do you expect your database to contact the ESP?
reading or writing is usually initiated [u]by a client[/u] of the Database. (with MySql you could have User Defined Functions within the DB that could trigger an HTTP request but this is not a great practice).
MySql has a REST API you could trigger through http from your ESP but probably best would be to not make your DB directly accessible from the internet and only have a higher level abstraction web server (PHP, Python, ...) that would be your interface to access the DB and read/write the data you want (possibly returning JSON formatted stuff)
I think You should explore first how to reach out from your ESP to a webServer (ie you are a client) and how to receive incoming HTTP request (your ESP is the Server). There are plenty of tutorials for this.
You should explore how database and SQL work.
You should learn the basics of how to program on the server side (PHP or Python for example)
then you should be able to build something ... won't happen in a few hours though