Connection String

PHP5 :

<?php
// Create connection
$con=mysqli_connect("example.com","peter","abc123","my_db");

// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

OLD Method:

<?php
$username = "";
$password = "";
$hostname = "localhost";
$database = "";

$conn = mysql_connect($hostname, $username, $password)
or die("Connecting to MySQL failed");

mysql_select_db($database, $conn)
or die("Selecting MySQL database failed");

mysql_close($conn);
?>