Get first post link in Wordpress

functions.php

<?php
function get_first_post_link() {
	global $wpdb, $table_prefix;
	$result = $wpdb->get_row("select * from {$table_prefix}posts where post_type = 'post' and post_status = 'publish' ORDER BY `{$table_prefix}posts`.`ID` ASC LIMIT 1");
	if($result) {
		return get_permalink( $result->ID );
	}
}

echo get_first_post_link();