How can you connect to MySQL from PHP?

Ans.  

Create a Connection to a MySQL Database

In PHP, this is done with the mysql_connect() function.

In the following example we store the connection in a variable ($con) for later use in the script. The "die" part will be executed if the connection fails:

<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

// some code
?>

What are the current versions of apache, PHP, and MySQL?

Ans.  

 The current versions of apache is 

Stable Release:

2.2.21 (released 2011-09-13)

The current versions of PHP is

Stable Releases

Current PHP 5.3 Stable: 5.3.8

and The current versions of MySQL is

Stable release 5.5.17