function wc_update_200_file_paths() {
	global $wpdb;

	// Upgrade old style files paths to support multiple file paths.
	$existing_file_paths = $wpdb->get_results( "SELECT meta_value, meta_id, post_id FROM {$wpdb->postmeta} WHERE meta_key = '_file_path' AND meta_value != '';" );

	if ( $existing_file_paths ) {

		foreach ( $existing_file_paths as $existing_file_path ) {

			$old_file_path = trim( $existing_file_path->meta_value );

			if ( ! empty( $old_file_path ) ) {
				$file_paths = serialize( array( md5( $old_file_path ) => $old_file_path ) );

				$wpdb->query( $wpdb->prepare( "UPDATE {$wpdb->postmeta} SET meta_key = '_file_paths', meta_value = %s WHERE meta_id = %d", $file_paths, $existing_file_path->meta_id ) );

				$wpdb->query( $wpdb->prepare( "UPDATE {$wpdb->prefix}woocommerce_downloadable_product_permissions SET download_id = %s WHERE product_id = %d", md5( $old_file_path ), $existing_file_path->post_id ) );

			}
		}
	}
}