Connecting to MySQL database via PHP script

script.php

<?php

$host = '127.0.0.1';
$user = 'abc';
$pwd = 'abc';
$db = 'xyz';

$con = mysql_connect($host, $user, $pwd) or die("connection failed");
	mysql_select_db($db,$con) or die("db selection failed");

	$r=mysql_query("select * from class",$con);

	while($row=mysql_fetch_array($r))
	{
		$cls[]=$row;
	}

	print(json_encode($cls));
	mysql_close($con);
?>