Script to do a bulk change of Drupal 6 user email domains

gistfile1.aw

<?php

/*
 * Does a bulk change of email addresses stored in a Drupal 6 database, eg from *@example.com to *@new-example.com
 *
 * Ensure that a backup is taken before running this.
 * 0. TAKE A BACKUP OF YOUR DATABASE - mysqldump -u[username] -p[password] [dbname] > [dbname].sql
 * 1. Fill out the details below
 * 2. Upload this somewhere accessible over the web
 * 3. Point your browser to it
 */

$dbname 		= 'example_database';
$username 		= 'example_database_username';
$password 		= 'example_database_password';
$existing_domain 	= '@example.com';
$target_domain		= '@new-example.com';

/* Thats it - stop editing */


try {
	
	$dbh = new PDO("mysql:host=localhost;dbname=".$dbname, $username, $password);
	
	$sql_select = 'SELECT uid,mail FROM users WHERE mail LIKE "%' . $existing_domain . '"';
	
	$result = $dbh->query($sql_select);
	
	foreach($result as $row) {
		
		$user_id       = $row['uid'];
		$current_email = $row['mail'];
		$updated_email = str_replace($existing_domain, $target_domain, $current_email);
	
		$sql_update = 'UPDATE users SET mail=? WHERE uid=?';
		
		$query = $dbh->prepare($sql_update);
		
		$query->execute(array($updated_email, $user_id));
	
	  echo $current_email . ' => ' . $updated_email . '<br />';
	
	}

}
catch(PDOException $e) {
	
	echo $e->getMessage();

}