Adds slashes to SQL queries.
addslashes() prepares query strings for SQL servers by adding backslash where needed for quotes and backslashes.
<?php
$msg = "Don't do it";
$query = "SELECT * FROM table WHERE msg = '" . addslashes($msg) . "'";
print $query;
?>
SELECT * FROM table WHERE msg = 'Don\'t do it'
A backslash is added to the query.