Get Posts by First Letter

<?php
/*
Name: Get Posts by First Letter.
Author: Iftekhar
Author URI: http://www.tips4blog.com/
*/

function get_post_by_first_letters($letter) {
        global $wpdb;
        $table_name = $wpdb->prefix."posts";
        $sql="SELECT ID, post_title FROM $table_name WHERE post_title LIKE '$letter%' AND post_type = 'post'";
        $result = $wpdb->get_results($sql);
        if($result === NULL){
                $result = 0;
        }
        return $result;
}
$post_title = get_post_by_first_letters('H');
echo '<ul>';
foreach($post_title as $title) {
    echo '<li><a href="' . get_permalink($title->ID) . '">' . $title->post_title . '</a></li>';
}
echo '</ul>'