Working with databases in PHP. MySQL module

If before (before php 5.0) it was possible to use a more or less trivial way of working with databases in php (using the MySQL module), then with new versions of php it is necessary to switch to new modules, such as mysqli or pdo. The MySQL module is deprecated in php 5.5.x and will soon be completely excluded.

In this note we will remind you how to use the MySQL module, but use modern interfaces for work (see the next notes). To use the minimum functionality of the MySQL module you only need to remember a few functions (of course, there are many more of them, here only the necessary minimum is presented).