Best way to connect to MySQL with PHP securely [duplicate]

Question

I want some input on what you guys think is the most secure way to connect to a MySQL database using PHP. Currently the way I'm doing it is a utility PHP file that I include in the top of all my other PHP files. The utility PHP file is this:

<?php     if(!defined('IN_PHP')){         die("hackerssss");     }     $mysql_host = "localhost";     $mysql_user = "root";     $mysql_pass = "root";     $mysql_db = cokertrading; ?> 

Any suggestions?

Answer 1

Suggestion: You should probably never be running as root; create another account and give it the 'least' privileges required for your site.

Answer 2

I can believe noone has mentioned MYSQLI and prepared statements yet, you may lock your password and database connection away, but thats ultimately futile if I can simply type ';DROP TABLE users;-- in the login form.

Check http://en.wikipedia.org/wiki/SQL_injection for an idea about what I'm talking about.