On what resource is the protection of php c mysql work well described?

Question

MySQL

Good afternoon, please tell me on which resource you can read the most complete information about secure queries to the database from php to mysql and its maintenance in general.
Before that, I somehow came across articles, but with each new one I realized that I got only pieces of a big pie.
At the moment, I need to make a site for a friend that could only be maintained by him alone, having access to adding pictures and text, and I would not want to substitute him, although we are working with him for the idea, but I don’t want to say, “well, I’m sorry” after .
Please do not leave useless comments or a link to search engines, I found these pieces there (maybe I searched badly or entered the request incorrectly).

Answer 1

php.net/manual/ru/book.pdo.php
is all that is required

Answer 2

I need to make a site for a friend that could only be maintained by him alone with access to adding pictures and text

wordpers?