WordPress - Set no index on a bulk list of URLs

snippet.php

<?php
function noindex_urls() {
	global $wpdb;
	
	$debug = true;
	
	$urls = array(
		'http://example.com/ok',
		'http://example.com/blah/?g=ok',
		'http://example.com/blah/foo/'
	);
	$new_urls = array();

	foreach( $urls as $url ) {
		// Only get the actual permalink, remove any query strings
		$url 		= explode( '?', $url );
		
		// We only want the end part of the URL
		$url_parts 	= explode( '/', $url[0] );
		$part 		= $url_parts[ count( $url_parts ) - 1 ];
		if( empty( $part ) ) {
			$part = $url_parts[ count( $url_parts ) - 2 ];
		}
		
		// Get the post ID from the database that matches our URL part
		$id = $wpdb->get_var("SELECT ID from $wpdb->posts WHERE post_name='$part'");

		// Get the permalink for the post
		$permalink = get_permalink( $id );

		// If our URL matches the permalink of the post we found, then set Yoast noindex to true
		if( $url[0] == $permalink ) {
			$new_urls[ $id ] = $url[0];
			update_post_meta( $id, '_yoast_wpseo_meta-robots-noindex', 1 );
		} else {
			if( $debug ) echo $url[0] . ' - ' . $permalink . ' dont match<br>';
		}
	}
	
	// A print of the URLs that were updated
	if( $debug ) {
		echo "<pre>";
		print_r( $new_urls );
		echo "</pre>";
	}
}